ClickHouse/src/Storages/StorageReplicatedMergeTree.cpp
2022-03-25 15:54:05 +01:00

7914 lines
326 KiB
C++

#include <Core/Defines.h>
#include "Common/hex.h"
#include <Common/Macros.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/ZooKeeper/KeeperException.h>
#include <Common/ZooKeeper/Types.h>
#include <Common/escapeForFileName.h>
#include <Common/formatReadable.h>
#include <Common/thread_local_rng.h>
#include <Common/typeid_cast.h>
#include <base/sort.h>
#include <Storages/AlterCommands.h>
#include <Storages/PartitionCommands.h>
#include <Storages/ColumnsDescription.h>
#include <Storages/StorageReplicatedMergeTree.h>
#include <Storages/MergeTree/IMergeTreeDataPart.h>
#include <Storages/MergeTree/MergeList.h>
#include <Storages/MergeTree/MergeTreeBackgroundExecutor.h>
#include <Storages/MergeTree/MergedBlockOutputStream.h>
#include <Storages/MergeTree/PinnedPartUUIDs.h>
#include <Storages/MergeTree/ReplicatedMergeTreeTableMetadata.h>
#include <Storages/MergeTree/ReplicatedMergeTreeSink.h>
#include <Storages/MergeTree/ReplicatedMergeTreeQuorumEntry.h>
#include <Storages/MergeTree/ReplicatedMergeTreeMutationEntry.h>
#include <Storages/MergeTree/ReplicatedMergeTreeAddress.h>
#include <Storages/MergeTree/ReplicatedMergeTreeQuorumAddedParts.h>
#include <Storages/MergeTree/ReplicatedMergeTreePartHeader.h>
#include <Storages/MergeTree/MergeFromLogEntryTask.h>
#include <Storages/MergeTree/MutateFromLogEntryTask.h>
#include <Storages/VirtualColumnUtils.h>
#include <Storages/MergeTree/MergeTreeReaderCompact.h>
#include <Storages/MergeTree/LeaderElection.h>
#include <Storages/MergeTree/ZeroCopyLock.h>
#include <Databases/DatabaseOnDisk.h>
#include <Parsers/formatAST.h>
#include <Parsers/parseQuery.h>
#include <Parsers/ASTDropQuery.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTOptimizeQuery.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/queryToString.h>
#include <Parsers/ASTCheckQuery.h>
#include <Parsers/ExpressionListParsers.h>
#include <Processors/QueryPlan/QueryPlan.h>
#include <Processors/Sources/RemoteSource.h>
#include <Processors/QueryPlan/BuildQueryPipelineSettings.h>
#include <Processors/QueryPlan/Optimizations/QueryPlanOptimizationSettings.h>
#include <Processors/QueryPlan/ReadFromPreparedSource.h>
#include <IO/ReadBufferFromString.h>
#include <IO/Operators.h>
#include <IO/ConnectionTimeouts.h>
#include <IO/ConnectionTimeoutsContext.h>
#include <Interpreters/InterpreterAlterQuery.h>
#include <Interpreters/PartLog.h>
#include <Interpreters/Context.h>
#include <Interpreters/DDLTask.h>
#include <Interpreters/InterserverCredentials.h>
#include <Interpreters/SelectQueryOptions.h>
#include <Interpreters/InterpreterSelectQuery.h>
#include <Poco/DirectoryIterator.h>
#include <base/scope_guard.h>
#include <base/scope_guard_safe.h>
#include <boost/algorithm/string/join.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <algorithm>
#include <ctime>
#include <filesystem>
#include <iterator>
#include <numeric>
#include <thread>
#include <future>
namespace fs = std::filesystem;
namespace ProfileEvents
{
extern const Event ReplicatedPartFailedFetches;
extern const Event ReplicatedPartFetchesOfMerged;
extern const Event ObsoleteReplicatedParts;
extern const Event ReplicatedPartFetches;
extern const Event CreatedLogEntryForMerge;
extern const Event NotCreatedLogEntryForMerge;
extern const Event CreatedLogEntryForMutation;
extern const Event NotCreatedLogEntryForMutation;
}
namespace CurrentMetrics
{
extern const Metric BackgroundFetchesPoolTask;
}
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_READ_ALL_DATA;
extern const int NOT_IMPLEMENTED;
extern const int NO_ZOOKEEPER;
extern const int INCORRECT_DATA;
extern const int INCOMPATIBLE_COLUMNS;
extern const int REPLICA_IS_ALREADY_EXIST;
extern const int NO_REPLICA_HAS_PART;
extern const int LOGICAL_ERROR;
extern const int TOO_MANY_UNEXPECTED_DATA_PARTS;
extern const int ABORTED;
extern const int REPLICA_IS_NOT_IN_QUORUM;
extern const int TABLE_IS_READ_ONLY;
extern const int NOT_FOUND_NODE;
extern const int NO_ACTIVE_REPLICAS;
extern const int NOT_A_LEADER;
extern const int TABLE_WAS_NOT_DROPPED;
extern const int PARTITION_ALREADY_EXISTS;
extern const int TOO_MANY_RETRIES_TO_FETCH_PARTS;
extern const int RECEIVED_ERROR_FROM_REMOTE_IO_SERVER;
extern const int PARTITION_DOESNT_EXIST;
extern const int UNFINISHED;
extern const int RECEIVED_ERROR_TOO_MANY_REQUESTS;
extern const int PART_IS_TEMPORARILY_LOCKED;
extern const int CANNOT_ASSIGN_OPTIMIZE;
extern const int KEEPER_EXCEPTION;
extern const int ALL_REPLICAS_LOST;
extern const int REPLICA_STATUS_CHANGED;
extern const int CANNOT_ASSIGN_ALTER;
extern const int DIRECTORY_ALREADY_EXISTS;
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
extern const int UNKNOWN_POLICY;
extern const int NO_SUCH_DATA_PART;
extern const int INTERSERVER_SCHEME_DOESNT_MATCH;
extern const int DUPLICATE_DATA_PART;
extern const int BAD_ARGUMENTS;
extern const int CONCURRENT_ACCESS_NOT_SUPPORTED;
extern const int CHECKSUM_DOESNT_MATCH;
}
namespace ActionLocks
{
extern const StorageActionBlockType PartsMerge;
extern const StorageActionBlockType PartsFetch;
extern const StorageActionBlockType PartsSend;
extern const StorageActionBlockType ReplicationQueue;
extern const StorageActionBlockType PartsTTLMerge;
extern const StorageActionBlockType PartsMove;
}
static const auto QUEUE_UPDATE_ERROR_SLEEP_MS = 1 * 1000;
static const auto MUTATIONS_FINALIZING_SLEEP_MS = 1 * 1000;
static const auto MUTATIONS_FINALIZING_IDLE_SLEEP_MS = 5 * 1000;
void StorageReplicatedMergeTree::setZooKeeper()
{
/// Every ReplicatedMergeTree table is using only one ZooKeeper session.
/// But if several ReplicatedMergeTree tables are using different
/// ZooKeeper sessions, some queries like ATTACH PARTITION FROM may have
/// strange effects. So we always use only one session for all tables.
/// (excluding auxiliary zookeepers)
std::lock_guard lock(current_zookeeper_mutex);
if (zookeeper_name == default_zookeeper_name)
{
current_zookeeper = getContext()->getZooKeeper();
}
else
{
current_zookeeper = getContext()->getAuxiliaryZooKeeper(zookeeper_name);
}
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::tryGetZooKeeper() const
{
std::lock_guard lock(current_zookeeper_mutex);
return current_zookeeper;
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::getZooKeeper() const
{
auto res = tryGetZooKeeper();
if (!res)
throw Exception("Cannot get ZooKeeper", ErrorCodes::NO_ZOOKEEPER);
return res;
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::getZooKeeperAndAssertNotReadonly() const
{
/// There's a short period of time after connection loss when new session is created,
/// but replication queue is not reinitialized. We must ensure that table is not readonly anymore
/// before using new ZooKeeper session to write something (except maybe GET_PART) into replication log.
auto res = getZooKeeper();
assertNotReadonly();
return res;
}
static MergeTreePartInfo makeDummyDropRangeForMovePartitionOrAttachPartitionFrom(const String & partition_id)
{
/// NOTE We don't have special log entry type for MOVE PARTITION/ATTACH PARTITION FROM,
/// so we use REPLACE_RANGE with dummy range of one block, which means "attach, not replace".
/// It's safe to fill drop range for MOVE PARTITION/ATTACH PARTITION FROM with zeros,
/// because drop range for REPLACE PARTITION must contain at least 2 blocks,
/// so we can distinguish dummy drop range from any real or virtual part.
/// But we should never construct such part name, even for virtual part,
/// because it can be confused with real part <partition>_0_0_0.
/// TODO get rid of this.
MergeTreePartInfo drop_range;
drop_range.partition_id = partition_id;
drop_range.min_block = 0;
drop_range.max_block = 0;
drop_range.level = 0;
drop_range.mutation = 0;
return drop_range;
}
StorageReplicatedMergeTree::StorageReplicatedMergeTree(
const String & zookeeper_path_,
const String & replica_name_,
bool attach,
const StorageID & table_id_,
const String & relative_data_path_,
const StorageInMemoryMetadata & metadata_,
ContextMutablePtr context_,
const String & date_column_name,
const MergingParams & merging_params_,
std::unique_ptr<MergeTreeSettings> settings_,
bool has_force_restore_data_flag,
bool allow_renaming_)
: MergeTreeData(table_id_,
relative_data_path_,
metadata_,
context_,
date_column_name,
merging_params_,
std::move(settings_),
true, /// require_part_metadata
attach,
[this] (const std::string & name) { enqueuePartForCheck(name); })
, zookeeper_name(zkutil::extractZooKeeperName(zookeeper_path_))
, zookeeper_path(zkutil::extractZooKeeperPath(zookeeper_path_, /* check_starts_with_slash */ !attach, log))
, replica_name(replica_name_)
, replica_path(fs::path(zookeeper_path) / "replicas" / replica_name_)
, reader(*this)
, writer(*this)
, merger_mutator(*this,
getContext()->getSettingsRef().background_merges_mutations_concurrency_ratio *
getContext()->getSettingsRef().background_pool_size)
, merge_strategy_picker(*this)
, queue(*this, merge_strategy_picker)
, fetcher(*this)
, cleanup_thread(*this)
, part_check_thread(*this)
, restarting_thread(*this)
, part_moves_between_shards_orchestrator(*this)
, allow_renaming(allow_renaming_)
, replicated_fetches_pool_size(getContext()->getSettingsRef().background_fetches_pool_size)
, replicated_fetches_throttler(std::make_shared<Throttler>(getSettings()->max_replicated_fetches_network_bandwidth, getContext()->getReplicatedFetchesThrottler()))
, replicated_sends_throttler(std::make_shared<Throttler>(getSettings()->max_replicated_sends_network_bandwidth, getContext()->getReplicatedSendsThrottler()))
{
queue_updating_task = getContext()->getSchedulePool().createTask(
getStorageID().getFullTableName() + " (StorageReplicatedMergeTree::queueUpdatingTask)", [this]{ queueUpdatingTask(); });
mutations_updating_task = getContext()->getSchedulePool().createTask(
getStorageID().getFullTableName() + " (StorageReplicatedMergeTree::mutationsUpdatingTask)", [this]{ mutationsUpdatingTask(); });
merge_selecting_task = getContext()->getSchedulePool().createTask(
getStorageID().getFullTableName() + " (StorageReplicatedMergeTree::mergeSelectingTask)", [this] { mergeSelectingTask(); });
/// Will be activated if we win leader election.
merge_selecting_task->deactivate();
mutations_finalizing_task = getContext()->getSchedulePool().createTask(
getStorageID().getFullTableName() + " (StorageReplicatedMergeTree::mutationsFinalizingTask)", [this] { mutationsFinalizingTask(); });
if (getContext()->hasZooKeeper() || getContext()->hasAuxiliaryZooKeeper(zookeeper_name))
{
/// It's possible for getZooKeeper() to timeout if zookeeper host(s) can't
/// be reached. In such cases Poco::Exception is thrown after a connection
/// timeout - refer to src/Common/ZooKeeper/ZooKeeperImpl.cpp:866 for more info.
///
/// Side effect of this is that the CreateQuery gets interrupted and it exits.
/// But the data Directories for the tables being created aren't cleaned up.
/// This unclean state will hinder table creation on any retries and will
/// complain that the Directory for table already exists.
///
/// To achieve a clean state on failed table creations, catch this error and
/// call dropIfEmpty() method only if the operation isn't ATTACH then proceed
/// throwing the exception. Without this, the Directory for the tables need
/// to be manually deleted before retrying the CreateQuery.
try
{
if (zookeeper_name == default_zookeeper_name)
{
current_zookeeper = getContext()->getZooKeeper();
}
else
{
current_zookeeper = getContext()->getAuxiliaryZooKeeper(zookeeper_name);
}
}
catch (...)
{
if (!attach)
dropIfEmpty();
throw;
}
}
bool skip_sanity_checks = false;
if (current_zookeeper && current_zookeeper->exists(replica_path + "/flags/force_restore_data"))
{
skip_sanity_checks = true;
current_zookeeper->remove(replica_path + "/flags/force_restore_data");
LOG_WARNING(log, "Skipping the limits on severity of changes to data parts and columns (flag {}/flags/force_restore_data).", replica_path);
}
else if (has_force_restore_data_flag)
{
skip_sanity_checks = true;
LOG_WARNING(log, "Skipping the limits on severity of changes to data parts and columns (flag force_restore_data).");
}
loadDataParts(skip_sanity_checks);
if (!current_zookeeper)
{
if (!attach)
{
dropIfEmpty();
throw Exception("Can't create replicated table without ZooKeeper", ErrorCodes::NO_ZOOKEEPER);
}
/// Do not activate the replica. It will be readonly.
LOG_ERROR(log, "No ZooKeeper: table will be in readonly mode.");
has_metadata_in_zookeeper = std::nullopt;
return;
}
if (attach && !current_zookeeper->exists(zookeeper_path + "/metadata"))
{
LOG_WARNING(log, "No metadata in ZooKeeper for {}: table will be in readonly mode.", zookeeper_path);
has_metadata_in_zookeeper = false;
return;
}
auto metadata_snapshot = getInMemoryMetadataPtr();
/// May it be ZK lost not the whole root, so the upper check passed, but only the /replicas/replica
/// folder.
if (attach && !current_zookeeper->exists(replica_path))
{
LOG_WARNING(log, "No metadata in ZooKeeper for {}: table will be in readonly mode", replica_path);
has_metadata_in_zookeeper = false;
return;
}
has_metadata_in_zookeeper = true;
if (!attach)
{
if (!getDataParts().empty())
throw Exception("Data directory for table already contains data parts"
" - probably it was unclean DROP table or manual intervention."
" You must either clear directory by hand or use ATTACH TABLE"
" instead of CREATE TABLE if you need to use that parts.", ErrorCodes::INCORRECT_DATA);
try
{
bool is_first_replica = createTableIfNotExists(metadata_snapshot);
try
{
/// NOTE If it's the first replica, these requests to ZooKeeper look redundant, we already know everything.
/// We have to check granularity on other replicas. If it's fixed we
/// must create our new replica with fixed granularity and store this
/// information in /replica/metadata.
other_replicas_fixed_granularity = checkFixedGranularityInZookeeper();
checkTableStructure(zookeeper_path, metadata_snapshot);
Coordination::Stat metadata_stat;
current_zookeeper->get(zookeeper_path + "/metadata", &metadata_stat);
metadata_version = metadata_stat.version;
}
catch (Coordination::Exception & e)
{
if (!is_first_replica && e.code == Coordination::Error::ZNONODE)
throw Exception("Table " + zookeeper_path + " was suddenly removed.", ErrorCodes::ALL_REPLICAS_LOST);
else
throw;
}
if (!is_first_replica)
createReplica(metadata_snapshot);
}
catch (...)
{
/// If replica was not created, rollback creation of data directory.
dropIfEmpty();
throw;
}
}
else
{
/// In old tables this node may missing or be empty
String replica_metadata;
const bool replica_metadata_exists = current_zookeeper->tryGet(replica_path + "/metadata", replica_metadata);
if (!replica_metadata_exists || replica_metadata.empty())
{
/// We have to check shared node granularity before we create ours.
other_replicas_fixed_granularity = checkFixedGranularityInZookeeper();
ReplicatedMergeTreeTableMetadata current_metadata(*this, metadata_snapshot);
current_zookeeper->createOrUpdate(replica_path + "/metadata", current_metadata.toString(),
zkutil::CreateMode::Persistent);
}
checkTableStructure(replica_path, metadata_snapshot);
checkParts(skip_sanity_checks);
if (current_zookeeper->exists(replica_path + "/metadata_version"))
{
metadata_version = parse<int>(current_zookeeper->get(replica_path + "/metadata_version"));
}
else
{
/// This replica was created with old clickhouse version, so we have
/// to take version of global node. If somebody will alter our
/// table, then we will fill /metadata_version node in zookeeper.
/// Otherwise on the next restart we can again use version from
/// shared metadata node because it was not changed.
Coordination::Stat metadata_stat;
current_zookeeper->get(zookeeper_path + "/metadata", &metadata_stat);
metadata_version = metadata_stat.version;
}
/// Temporary directories contain uninitialized results of Merges or Fetches (after forced restart),
/// don't allow to reinitialize them, delete each of them immediately.
clearOldTemporaryDirectories(0);
clearOldWriteAheadLogs();
}
createNewZooKeeperNodes();
syncPinnedPartUUIDs();
createTableSharedID();
}
bool StorageReplicatedMergeTree::checkFixedGranularityInZookeeper()
{
auto zookeeper = getZooKeeper();
String metadata_str = zookeeper->get(zookeeper_path + "/metadata");
auto metadata_from_zk = ReplicatedMergeTreeTableMetadata::parse(metadata_str);
return metadata_from_zk.index_granularity_bytes == 0;
}
void StorageReplicatedMergeTree::waitMutationToFinishOnReplicas(
const Strings & replicas, const String & mutation_id) const
{
if (replicas.empty())
return;
std::set<String> inactive_replicas;
for (const String & replica : replicas)
{
LOG_DEBUG(log, "Waiting for {} to apply mutation {}", replica, mutation_id);
zkutil::EventPtr wait_event = std::make_shared<Poco::Event>();
while (!partial_shutdown_called)
{
/// Mutation maybe killed or whole replica was deleted.
/// Wait event will unblock at this moment.
Coordination::Stat exists_stat;
if (!getZooKeeper()->exists(fs::path(zookeeper_path) / "mutations" / mutation_id, &exists_stat, wait_event))
{
throw Exception(ErrorCodes::UNFINISHED, "Mutation {} was killed, manually removed or table was dropped", mutation_id);
}
auto zookeeper = getZooKeeper();
/// Replica could be inactive.
if (!zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active"))
{
LOG_WARNING(log, "Replica {} is not active during mutation. Mutation will be done asynchronously when replica becomes active.", replica);
inactive_replicas.emplace(replica);
break;
}
String mutation_pointer = fs::path(zookeeper_path) / "replicas" / replica / "mutation_pointer";
std::string mutation_pointer_value;
/// Replica could be removed
if (!zookeeper->tryGet(mutation_pointer, mutation_pointer_value, nullptr, wait_event))
{
LOG_WARNING(log, "Replica {} was removed", replica);
break;
}
else if (mutation_pointer_value >= mutation_id) /// Maybe we already processed more fresh mutation
break; /// (numbers like 0000000000 and 0000000001)
/// Replica can become inactive, so wait with timeout and recheck it
if (wait_event->tryWait(1000))
continue;
/// Here we check mutation for errors on local replica. If they happen on this replica
/// they will happen on each replica, so we can check only in-memory info.
auto mutation_status = queue.getIncompleteMutationsStatus(mutation_id);
/// If mutation status is empty, than local replica may just not loaded it into memory.
if (mutation_status && !mutation_status->latest_fail_reason.empty())
break;
}
/// This replica inactive, don't check anything
if (!inactive_replicas.empty() && inactive_replicas.count(replica))
break;
/// It maybe already removed from zk, but local in-memory mutations
/// state was not updated.
if (!getZooKeeper()->exists(fs::path(zookeeper_path) / "mutations" / mutation_id))
{
throw Exception(ErrorCodes::UNFINISHED, "Mutation {} was killed, manually removed or table was dropped", mutation_id);
}
if (partial_shutdown_called)
throw Exception("Mutation is not finished because table shutdown was called. It will be done after table restart.",
ErrorCodes::UNFINISHED);
/// Replica inactive, don't check mutation status
if (!inactive_replicas.empty() && inactive_replicas.count(replica))
continue;
/// At least we have our current mutation
std::set<String> mutation_ids;
mutation_ids.insert(mutation_id);
/// Here we check mutation for errors or kill on local replica. If they happen on this replica
/// they will happen on each replica, so we can check only in-memory info.
auto mutation_status = queue.getIncompleteMutationsStatus(mutation_id, &mutation_ids);
checkMutationStatus(mutation_status, mutation_ids);
}
if (!inactive_replicas.empty())
{
throw Exception(ErrorCodes::UNFINISHED,
"Mutation is not finished because some replicas are inactive right now: {}. Mutation will be done asynchronously",
boost::algorithm::join(inactive_replicas, ", "));
}
}
void StorageReplicatedMergeTree::createNewZooKeeperNodes()
{
auto zookeeper = getZooKeeper();
/// Working with quorum.
zookeeper->createIfNotExists(zookeeper_path + "/quorum", String());
zookeeper->createIfNotExists(zookeeper_path + "/quorum/parallel", String());
zookeeper->createIfNotExists(zookeeper_path + "/quorum/last_part", String());
zookeeper->createIfNotExists(zookeeper_path + "/quorum/failed_parts", String());
/// Tracking lag of replicas.
zookeeper->createIfNotExists(replica_path + "/min_unprocessed_insert_time", String());
zookeeper->createIfNotExists(replica_path + "/max_processed_insert_time", String());
/// Mutations
zookeeper->createIfNotExists(zookeeper_path + "/mutations", String());
zookeeper->createIfNotExists(replica_path + "/mutation_pointer", String());
/// Nodes for remote fs zero-copy replication
const auto settings = getSettings();
if (settings->allow_remote_fs_zero_copy_replication)
{
zookeeper->createIfNotExists(zookeeper_path + "/zero_copy_s3", String());
zookeeper->createIfNotExists(zookeeper_path + "/zero_copy_s3/shared", String());
zookeeper->createIfNotExists(zookeeper_path + "/zero_copy_hdfs", String());
zookeeper->createIfNotExists(zookeeper_path + "/zero_copy_hdfs/shared", String());
}
/// Part movement.
zookeeper->createIfNotExists(zookeeper_path + "/part_moves_shard", String());
zookeeper->createIfNotExists(zookeeper_path + "/pinned_part_uuids", getPinnedPartUUIDs()->toString());
/// For ALTER PARTITION with multi-leaders
zookeeper->createIfNotExists(zookeeper_path + "/alter_partition_version", String());
}
bool StorageReplicatedMergeTree::createTableIfNotExists(const StorageMetadataPtr & metadata_snapshot)
{
auto zookeeper = getZooKeeper();
zookeeper->createAncestors(zookeeper_path);
for (size_t i = 0; i < 1000; ++i)
{
/// Invariant: "replicas" does not exist if there is no table or if there are leftovers from incompletely dropped table.
if (zookeeper->exists(zookeeper_path + "/replicas"))
{
LOG_DEBUG(log, "This table {} is already created, will add new replica", zookeeper_path);
return false;
}
/// There are leftovers from incompletely dropped table.
if (zookeeper->exists(zookeeper_path + "/dropped"))
{
/// This condition may happen when the previous drop attempt was not completed
/// or when table is dropped by another replica right now.
/// This is Ok because another replica is definitely going to drop the table.
LOG_WARNING(log, "Removing leftovers from table {} (this might take several minutes)", zookeeper_path);
String drop_lock_path = zookeeper_path + "/dropped/lock";
Coordination::Error code = zookeeper->tryCreate(drop_lock_path, "", zkutil::CreateMode::Ephemeral);
if (code == Coordination::Error::ZNONODE || code == Coordination::Error::ZNODEEXISTS)
{
LOG_WARNING(log, "The leftovers from table {} were removed by another replica", zookeeper_path);
}
else if (code != Coordination::Error::ZOK)
{
throw Coordination::Exception(code, drop_lock_path);
}
else
{
auto metadata_drop_lock = zkutil::EphemeralNodeHolder::existing(drop_lock_path, *zookeeper);
if (!removeTableNodesFromZooKeeper(zookeeper, zookeeper_path, metadata_drop_lock, log))
{
/// Someone is recursively removing table right now, we cannot create new table until old one is removed
continue;
}
}
}
LOG_DEBUG(log, "Creating table {}", zookeeper_path);
/// We write metadata of table so that the replicas can check table parameters with them.
String metadata_str = ReplicatedMergeTreeTableMetadata(*this, metadata_snapshot).toString();
Coordination::Requests ops;
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path, "", zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/metadata", metadata_str,
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/columns", metadata_snapshot->getColumns().toString(),
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/log", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/blocks", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/block_numbers", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/nonincrement_block_numbers", "",
zkutil::CreateMode::Persistent)); /// /nonincrement_block_numbers dir is unused, but is created nonetheless for backwards compatibility.
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/leader_election", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/temp", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/replicas", "last added replica: " + replica_name,
zkutil::CreateMode::Persistent));
/// And create first replica atomically. See also "createReplica" method that is used to create not the first replicas.
ops.emplace_back(zkutil::makeCreateRequest(replica_path, "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/host", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/log_pointer", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/queue", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/parts", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/flags", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/is_lost", "0",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/metadata", metadata_str,
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/columns", metadata_snapshot->getColumns().toString(),
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/metadata_version", std::to_string(metadata_version),
zkutil::CreateMode::Persistent));
Coordination::Responses responses;
auto code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZNODEEXISTS)
{
LOG_WARNING(log, "It looks like the table {} was created by another server at the same moment, will retry", zookeeper_path);
continue;
}
else if (code != Coordination::Error::ZOK)
{
zkutil::KeeperMultiException::check(code, ops, responses);
}
return true;
}
/// Do not use LOGICAL_ERROR code, because it may happen if user has specified wrong zookeeper_path
throw Exception("Cannot create table, because it is created concurrently every time "
"or because of wrong zookeeper_path "
"or because of logical error", ErrorCodes::REPLICA_IS_ALREADY_EXIST);
}
void StorageReplicatedMergeTree::createReplica(const StorageMetadataPtr & metadata_snapshot)
{
auto zookeeper = getZooKeeper();
LOG_DEBUG(log, "Creating replica {}", replica_path);
Coordination::Error code;
do
{
Coordination::Stat replicas_stat;
String replicas_value;
if (!zookeeper->tryGet(zookeeper_path + "/replicas", replicas_value, &replicas_stat))
throw Exception(ErrorCodes::ALL_REPLICAS_LOST,
"Cannot create a replica of the table {}, because the last replica of the table was dropped right now",
zookeeper_path);
/// It is not the first replica, we will mark it as "lost", to immediately repair (clone) from existing replica.
/// By the way, it's possible that the replica will be first, if all previous replicas were removed concurrently.
const String is_lost_value = replicas_stat.numChildren ? "1" : "0";
Coordination::Requests ops;
ops.emplace_back(zkutil::makeCreateRequest(replica_path, "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/host", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/log_pointer", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/queue", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/parts", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/flags", "",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/is_lost", is_lost_value,
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/metadata", ReplicatedMergeTreeTableMetadata(*this, metadata_snapshot).toString(),
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/columns", metadata_snapshot->getColumns().toString(),
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(replica_path + "/metadata_version", std::to_string(metadata_version),
zkutil::CreateMode::Persistent));
/// Check version of /replicas to see if there are any replicas created at the same moment of time.
ops.emplace_back(zkutil::makeSetRequest(zookeeper_path + "/replicas", "last added replica: " + replica_name, replicas_stat.version));
Coordination::Responses responses;
code = zookeeper->tryMulti(ops, responses);
switch (code)
{
case Coordination::Error::ZNODEEXISTS:
throw Exception(ErrorCodes::REPLICA_IS_ALREADY_EXIST, "Replica {} already exists", replica_path);
case Coordination::Error::ZBADVERSION:
LOG_ERROR(log, "Retrying createReplica(), because some other replicas were created at the same time");
break;
case Coordination::Error::ZNONODE:
throw Exception(ErrorCodes::ALL_REPLICAS_LOST, "Table {} was suddenly removed", zookeeper_path);
default:
zkutil::KeeperMultiException::check(code, ops, responses);
}
} while (code == Coordination::Error::ZBADVERSION);
}
void StorageReplicatedMergeTree::drop()
{
/// There is also the case when user has configured ClickHouse to wrong ZooKeeper cluster
/// or metadata of staled replica were removed manually,
/// in this case, has_metadata_in_zookeeper = false, and we also permit to drop the table.
bool maybe_has_metadata_in_zookeeper = !has_metadata_in_zookeeper.has_value() || *has_metadata_in_zookeeper;
if (maybe_has_metadata_in_zookeeper)
{
/// Table can be shut down, restarting thread is not active
/// and calling StorageReplicatedMergeTree::getZooKeeper()/getAuxiliaryZooKeeper() won't suffice.
zkutil::ZooKeeperPtr zookeeper;
if (zookeeper_name == default_zookeeper_name)
zookeeper = getContext()->getZooKeeper();
else
zookeeper = getContext()->getAuxiliaryZooKeeper(zookeeper_name);
/// If probably there is metadata in ZooKeeper, we don't allow to drop the table.
if (!zookeeper)
throw Exception("Can't drop readonly replicated table (need to drop data in ZooKeeper as well)", ErrorCodes::TABLE_IS_READ_ONLY);
shutdown();
dropReplica(zookeeper, zookeeper_path, replica_name, log);
}
dropAllData();
}
void StorageReplicatedMergeTree::dropReplica(zkutil::ZooKeeperPtr zookeeper, const String & zookeeper_path, const String & replica, Poco::Logger * logger)
{
if (zookeeper->expired())
throw Exception("Table was not dropped because ZooKeeper session has expired.", ErrorCodes::TABLE_WAS_NOT_DROPPED);
auto remote_replica_path = zookeeper_path + "/replicas/" + replica;
LOG_INFO(logger, "Removing replica {}, marking it as lost", remote_replica_path);
/// Mark itself lost before removing, because the following recursive removal may fail
/// and partially dropped replica may be considered as alive one (until someone will mark it lost)
zookeeper->trySet(remote_replica_path + "/is_lost", "1");
/// NOTE: we should check for remote_replica_path existence,
/// since otherwise DROP REPLICA will fail if the replica had been already removed.
if (!zookeeper->exists(remote_replica_path))
{
LOG_INFO(logger, "Removing replica {} does not exist", remote_replica_path);
return;
}
/// Analog of removeRecursive(remote_replica_path)
/// but it removes "metadata" firstly.
///
/// This will allow to mark table as readonly
/// and skip any checks of parts between on-disk and in the zookeeper.
///
/// Without this removeRecursive() may remove "parts" first
/// and on DETACH/ATTACH (or server restart) it will trigger the following error:
///
/// "The local set of parts of table X doesn't look like the set of parts in ZooKeeper"
///
{
Strings children = zookeeper->getChildren(remote_replica_path);
if (std::find(children.begin(), children.end(), "metadata") != children.end())
zookeeper->remove(fs::path(remote_replica_path) / "metadata");
for (const auto & child : children)
{
if (child != "metadata")
zookeeper->removeRecursive(fs::path(remote_replica_path) / child);
}
zookeeper->remove(remote_replica_path);
}
/// It may left some garbage if replica_path subtree are concurrently modified
if (zookeeper->exists(remote_replica_path))
LOG_ERROR(logger, "Replica was not completely removed from ZooKeeper, {} still exists and may contain some garbage.", remote_replica_path);
/// Check that `zookeeper_path` exists: it could have been deleted by another replica after execution of previous line.
Strings replicas;
if (Coordination::Error::ZOK != zookeeper->tryGetChildren(zookeeper_path + "/replicas", replicas) || !replicas.empty())
return;
LOG_INFO(logger, "{} is the last replica, will remove table", remote_replica_path);
/** At this moment, another replica can be created and we cannot remove the table.
* Try to remove /replicas node first. If we successfully removed it,
* it guarantees that we are the only replica that proceed to remove the table
* and no new replicas can be created after that moment (it requires the existence of /replicas node).
* and table cannot be recreated with new /replicas node on another servers while we are removing data,
* because table creation is executed in single transaction that will conflict with remaining nodes.
*/
/// Node /dropped works like a lock that protects from concurrent removal of old table and creation of new table.
/// But recursive removal may fail in the middle of operation leaving some garbage in zookeeper_path, so
/// we remove it on table creation if there is /dropped node. Creating thread may remove /dropped node created by
/// removing thread, and it causes race condition if removing thread is not finished yet.
/// To avoid this we also create ephemeral child before starting recursive removal.
/// (The existence of child node does not allow to remove parent node).
Coordination::Requests ops;
Coordination::Responses responses;
String drop_lock_path = zookeeper_path + "/dropped/lock";
ops.emplace_back(zkutil::makeRemoveRequest(zookeeper_path + "/replicas", -1));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_path + "/dropped", "", zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(drop_lock_path, "", zkutil::CreateMode::Ephemeral));
Coordination::Error code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZNONODE || code == Coordination::Error::ZNODEEXISTS)
{
LOG_WARNING(logger, "Table {} is already started to be removing by another replica right now", remote_replica_path);
}
else if (code == Coordination::Error::ZNOTEMPTY)
{
LOG_WARNING(logger, "Another replica was suddenly created, will keep the table {}", remote_replica_path);
}
else if (code != Coordination::Error::ZOK)
{
zkutil::KeeperMultiException::check(code, ops, responses);
}
else
{
auto metadata_drop_lock = zkutil::EphemeralNodeHolder::existing(drop_lock_path, *zookeeper);
LOG_INFO(logger, "Removing table {} (this might take several minutes)", zookeeper_path);
removeTableNodesFromZooKeeper(zookeeper, zookeeper_path, metadata_drop_lock, logger);
}
}
bool StorageReplicatedMergeTree::removeTableNodesFromZooKeeper(zkutil::ZooKeeperPtr zookeeper,
const String & zookeeper_path, const zkutil::EphemeralNodeHolder::Ptr & metadata_drop_lock, Poco::Logger * logger)
{
bool completely_removed = false;
Strings children;
Coordination::Error code = zookeeper->tryGetChildren(zookeeper_path, children);
if (code == Coordination::Error::ZNONODE)
throw Exception(ErrorCodes::LOGICAL_ERROR, "There is a race condition between creation and removal of replicated table. It's a bug");
for (const auto & child : children)
if (child != "dropped")
zookeeper->tryRemoveRecursive(fs::path(zookeeper_path) / child);
Coordination::Requests ops;
Coordination::Responses responses;
ops.emplace_back(zkutil::makeRemoveRequest(metadata_drop_lock->getPath(), -1));
ops.emplace_back(zkutil::makeRemoveRequest(fs::path(zookeeper_path) / "dropped", -1));
ops.emplace_back(zkutil::makeRemoveRequest(zookeeper_path, -1));
code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZNONODE)
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "There is a race condition between creation and removal of replicated table. It's a bug");
}
else if (code == Coordination::Error::ZNOTEMPTY)
{
LOG_ERROR(logger, "Table was not completely removed from ZooKeeper, {} still exists and may contain some garbage,"
"but someone is removing it right now.", zookeeper_path);
}
else if (code != Coordination::Error::ZOK)
{
/// It is still possible that ZooKeeper session is expired or server is killed in the middle of the delete operation.
zkutil::KeeperMultiException::check(code, ops, responses);
}
else
{
metadata_drop_lock->setAlreadyRemoved();
completely_removed = true;
LOG_INFO(logger, "Table {} was successfully removed from ZooKeeper", zookeeper_path);
}
return completely_removed;
}
/** Verify that list of columns and table storage_settings_ptr match those specified in ZK (/metadata).
* If not, throw an exception.
*/
void StorageReplicatedMergeTree::checkTableStructure(const String & zookeeper_prefix, const StorageMetadataPtr & metadata_snapshot)
{
auto zookeeper = getZooKeeper();
ReplicatedMergeTreeTableMetadata old_metadata(*this, metadata_snapshot);
Coordination::Stat metadata_stat;
String metadata_str = zookeeper->get(fs::path(zookeeper_prefix) / "metadata", &metadata_stat);
auto metadata_from_zk = ReplicatedMergeTreeTableMetadata::parse(metadata_str);
old_metadata.checkEquals(metadata_from_zk, metadata_snapshot->getColumns(), getContext());
Coordination::Stat columns_stat;
auto columns_from_zk = ColumnsDescription::parse(zookeeper->get(fs::path(zookeeper_prefix) / "columns", &columns_stat));
const ColumnsDescription & old_columns = metadata_snapshot->getColumns();
if (columns_from_zk != old_columns)
{
throw Exception(ErrorCodes::INCOMPATIBLE_COLUMNS,
"Table columns structure in ZooKeeper is different from local table structure. Local columns:\n"
"{}\nZookeeper columns:\n{}", old_columns.toString(), columns_from_zk.toString());
}
}
void StorageReplicatedMergeTree::setTableStructure(
ColumnsDescription new_columns, const ReplicatedMergeTreeTableMetadata::Diff & metadata_diff)
{
StorageInMemoryMetadata new_metadata = getInMemoryMetadata();
StorageInMemoryMetadata old_metadata = getInMemoryMetadata();
new_metadata.columns = new_columns;
if (!metadata_diff.empty())
{
auto parse_key_expr = [] (const String & key_expr)
{
ParserNotEmptyExpressionList parser(false);
auto new_sorting_key_expr_list = parseQuery(parser, key_expr, 0, DBMS_DEFAULT_MAX_PARSER_DEPTH);
ASTPtr order_by_ast;
if (new_sorting_key_expr_list->children.size() == 1)
order_by_ast = new_sorting_key_expr_list->children[0];
else
{
auto tuple = makeASTFunction("tuple");
tuple->arguments->children = new_sorting_key_expr_list->children;
order_by_ast = tuple;
}
return order_by_ast;
};
if (metadata_diff.sorting_key_changed)
{
auto order_by_ast = parse_key_expr(metadata_diff.new_sorting_key);
auto & sorting_key = new_metadata.sorting_key;
auto & primary_key = new_metadata.primary_key;
sorting_key.recalculateWithNewAST(order_by_ast, new_metadata.columns, getContext());
if (primary_key.definition_ast == nullptr)
{
/// Primary and sorting key become independent after this ALTER so we have to
/// save the old ORDER BY expression as the new primary key.
auto old_sorting_key_ast = old_metadata.getSortingKey().definition_ast;
primary_key = KeyDescription::getKeyFromAST(
old_sorting_key_ast, new_metadata.columns, getContext());
}
}
if (metadata_diff.sampling_expression_changed)
{
if (!metadata_diff.new_sampling_expression.empty())
{
auto sample_by_ast = parse_key_expr(metadata_diff.new_sampling_expression);
new_metadata.sampling_key.recalculateWithNewAST(sample_by_ast, new_metadata.columns, getContext());
}
else /// SAMPLE BY was removed
{
new_metadata.sampling_key = {};
}
}
if (metadata_diff.skip_indices_changed)
new_metadata.secondary_indices = IndicesDescription::parse(metadata_diff.new_skip_indices, new_columns, getContext());
if (metadata_diff.constraints_changed)
new_metadata.constraints = ConstraintsDescription::parse(metadata_diff.new_constraints);
if (metadata_diff.projections_changed)
new_metadata.projections = ProjectionsDescription::parse(metadata_diff.new_projections, new_columns, getContext());
if (metadata_diff.ttl_table_changed)
{
if (!metadata_diff.new_ttl_table.empty())
{
ParserTTLExpressionList parser;
auto ttl_for_table_ast = parseQuery(parser, metadata_diff.new_ttl_table, 0, DBMS_DEFAULT_MAX_PARSER_DEPTH);
new_metadata.table_ttl = TTLTableDescription::getTTLForTableFromAST(
ttl_for_table_ast, new_metadata.columns, getContext(), new_metadata.primary_key);
}
else /// TTL was removed
{
new_metadata.table_ttl = TTLTableDescription{};
}
}
}
/// Changes in columns may affect following metadata fields
new_metadata.column_ttls_by_name.clear();
for (const auto & [name, ast] : new_metadata.columns.getColumnTTLs())
{
auto new_ttl_entry = TTLDescription::getTTLFromAST(ast, new_metadata.columns, getContext(), new_metadata.primary_key);
new_metadata.column_ttls_by_name[name] = new_ttl_entry;
}
if (new_metadata.partition_key.definition_ast != nullptr)
new_metadata.partition_key.recalculateWithNewColumns(new_metadata.columns, getContext());
if (!metadata_diff.sorting_key_changed) /// otherwise already updated
new_metadata.sorting_key.recalculateWithNewColumns(new_metadata.columns, getContext());
/// Primary key is special, it exists even if not defined
if (new_metadata.primary_key.definition_ast != nullptr)
{
new_metadata.primary_key.recalculateWithNewColumns(new_metadata.columns, getContext());
}
else
{
new_metadata.primary_key = KeyDescription::getKeyFromAST(new_metadata.sorting_key.definition_ast, new_metadata.columns, getContext());
new_metadata.primary_key.definition_ast = nullptr;
}
if (!metadata_diff.sampling_expression_changed && new_metadata.sampling_key.definition_ast != nullptr)
new_metadata.sampling_key.recalculateWithNewColumns(new_metadata.columns, getContext());
if (!metadata_diff.skip_indices_changed) /// otherwise already updated
{
for (auto & index : new_metadata.secondary_indices)
index.recalculateWithNewColumns(new_metadata.columns, getContext());
}
if (!metadata_diff.ttl_table_changed && new_metadata.table_ttl.definition_ast != nullptr)
new_metadata.table_ttl = TTLTableDescription::getTTLForTableFromAST(
new_metadata.table_ttl.definition_ast, new_metadata.columns, getContext(), new_metadata.primary_key);
/// Even if the primary/sorting/partition keys didn't change we must reinitialize it
/// because primary/partition key column types might have changed.
checkTTLExpressions(new_metadata, old_metadata);
setProperties(new_metadata, old_metadata);
auto table_id = getStorageID();
DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(getContext(), table_id, new_metadata);
}
/** If necessary, restore a part, replica itself adds a record for its receipt.
* What time should I put for this entry in the queue? Time is taken into account when calculating lag of replica.
* For these purposes, it makes sense to use creation time of missing part
* (that is, in calculating lag, it will be taken into account how old is the part we need to recover).
*/
static time_t tryGetPartCreateTime(zkutil::ZooKeeperPtr & zookeeper, const String & replica_path, const String & part_name)
{
time_t res = 0;
/// We get creation time of part, if it still exists (was not merged, for example).
Coordination::Stat stat;
String unused;
if (zookeeper->tryGet(fs::path(replica_path) / "parts" / part_name, unused, &stat))
res = stat.ctime / 1000;
return res;
}
void StorageReplicatedMergeTree::checkParts(bool skip_sanity_checks)
{
auto zookeeper = getZooKeeper();
Strings expected_parts_vec = zookeeper->getChildren(fs::path(replica_path) / "parts");
/// Parts in ZK.
NameSet expected_parts(expected_parts_vec.begin(), expected_parts_vec.end());
/// There are no PreActive parts at startup.
auto parts = getDataParts({MergeTreeDataPartState::Active, MergeTreeDataPartState::Outdated});
/** Local parts that are not in ZK.
* In very rare cases they may cover missing parts
* and someone may think that pushing them to zookeeper is good idea.
* But actually we can't precisely determine that ALL missing parts
* covered by this unexpected part. So missing parts will be downloaded.
*/
DataParts unexpected_parts;
/// Collect unexpected parts
for (const auto & part : parts)
if (!expected_parts.count(part->name))
unexpected_parts.insert(part); /// this parts we will place to detached with ignored_ prefix
/// Which parts should be taken from other replicas.
Strings parts_to_fetch;
for (const String & missing_name : expected_parts)
if (!getActiveContainingPart(missing_name))
parts_to_fetch.push_back(missing_name);
/** To check the adequacy, for the parts that are in the FS, but not in ZK, we will only consider not the most recent parts.
* Because unexpected new parts usually arise only because they did not have time to enroll in ZK with a rough restart of the server.
* It also occurs from deduplicated parts that did not have time to retire.
*/
size_t unexpected_parts_nonnew = 0;
UInt64 unexpected_parts_nonnew_rows = 0;
UInt64 unexpected_parts_rows = 0;
for (const auto & part : unexpected_parts)
{
if (part->info.level > 0)
{
++unexpected_parts_nonnew;
unexpected_parts_nonnew_rows += part->rows_count;
}
unexpected_parts_rows += part->rows_count;
}
const UInt64 parts_to_fetch_blocks = std::accumulate(parts_to_fetch.cbegin(), parts_to_fetch.cend(), 0,
[&](UInt64 acc, const String& part_name)
{
if (const auto part_info = MergeTreePartInfo::tryParsePartName(part_name, format_version))
return acc + part_info->getBlocksCount();
LOG_ERROR(log, "Unexpected part name: {}", part_name);
return acc;
});
/** We can automatically synchronize data,
* if the ratio of the total number of errors to the total number of parts (minimum - on the local filesystem or in ZK)
* is no more than some threshold (for example 50%).
*
* A large ratio of mismatches in the data on the filesystem and the expected data
* may indicate a configuration error (the server accidentally connected as a replica not from right shard).
* In this case, the protection mechanism does not allow the server to start.
*/
UInt64 total_rows_on_filesystem = 0;
for (const auto & part : parts)
total_rows_on_filesystem += part->rows_count;
const auto storage_settings_ptr = getSettings();
bool insane = unexpected_parts_rows > total_rows_on_filesystem * storage_settings_ptr->replicated_max_ratio_of_wrong_parts;
constexpr const char * sanity_report_fmt = "The local set of parts of table {} doesn't look like the set of parts in ZooKeeper: "
"{} rows of {} total rows in filesystem are suspicious. "
"There are {} unexpected parts with {} rows ({} of them is not just-written with {} rows), "
"{} missing parts (with {} blocks).";
if (insane && !skip_sanity_checks)
{
throw Exception(ErrorCodes::TOO_MANY_UNEXPECTED_DATA_PARTS, sanity_report_fmt, getStorageID().getNameForLogs(),
formatReadableQuantity(unexpected_parts_rows), formatReadableQuantity(total_rows_on_filesystem),
unexpected_parts.size(), unexpected_parts_rows, unexpected_parts_nonnew, unexpected_parts_nonnew_rows,
parts_to_fetch.size(), parts_to_fetch_blocks);
}
if (unexpected_parts_nonnew_rows > 0)
{
LOG_WARNING(log, fmt::runtime(sanity_report_fmt), getStorageID().getNameForLogs(),
formatReadableQuantity(unexpected_parts_rows), formatReadableQuantity(total_rows_on_filesystem),
unexpected_parts.size(), unexpected_parts_rows, unexpected_parts_nonnew, unexpected_parts_nonnew_rows,
parts_to_fetch.size(), parts_to_fetch_blocks);
}
/// Add to the queue jobs to pick up the missing parts from other replicas and remove from ZK the information that we have them.
queue.setBrokenPartsToEnqueueFetchesOnLoading(std::move(parts_to_fetch));
/// Remove extra local parts.
for (const DataPartPtr & part : unexpected_parts)
{
LOG_ERROR(log, "Renaming unexpected part {} to ignored_{}", part->name, part->name);
forgetPartAndMoveToDetached(part, "ignored", true);
}
}
void StorageReplicatedMergeTree::syncPinnedPartUUIDs()
{
auto zookeeper = getZooKeeper();
Coordination::Stat stat;
String s = zookeeper->get(zookeeper_path + "/pinned_part_uuids", &stat);
std::lock_guard lock(pinned_part_uuids_mutex);
/// Unsure whether or not this can be called concurrently.
if (pinned_part_uuids->stat.version < stat.version)
{
auto new_pinned_part_uuids = std::make_shared<PinnedPartUUIDs>();
new_pinned_part_uuids->fromString(s);
new_pinned_part_uuids->stat = stat;
pinned_part_uuids = new_pinned_part_uuids;
}
}
void StorageReplicatedMergeTree::checkPartChecksumsAndAddCommitOps(const zkutil::ZooKeeperPtr & zookeeper,
const DataPartPtr & part, Coordination::Requests & ops, String part_name, NameSet * absent_replicas_paths)
{
if (part_name.empty())
part_name = part->name;
auto local_part_header = ReplicatedMergeTreePartHeader::fromColumnsAndChecksums(
part->getColumns(), part->checksums);
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
bool has_been_already_added = false;
for (const String & replica : replicas)
{
String current_part_path = fs::path(zookeeper_path) / "replicas" / replica / "parts" / part_name;
String part_zk_str;
if (!zookeeper->tryGet(current_part_path, part_zk_str))
{
if (absent_replicas_paths)
absent_replicas_paths->emplace(current_part_path);
continue;
}
ReplicatedMergeTreePartHeader replica_part_header;
if (part_zk_str.empty())
{
String columns_str;
String checksums_str;
if (zookeeper->tryGet(fs::path(current_part_path) / "columns", columns_str) &&
zookeeper->tryGet(fs::path(current_part_path) / "checksums", checksums_str))
{
replica_part_header = ReplicatedMergeTreePartHeader::fromColumnsAndChecksumsZNodes(columns_str, checksums_str);
}
else
{
if (zookeeper->exists(current_part_path))
throw Exception(ErrorCodes::LOGICAL_ERROR, "Part {} has empty header and does not have columns and checksums. "
"Looks like a bug.", current_part_path);
LOG_INFO(log, "Not checking checksums of part {} with replica {} because part was removed from ZooKeeper", part_name, replica);
continue;
}
}
else
{
replica_part_header = ReplicatedMergeTreePartHeader::fromString(part_zk_str);
}
if (replica_part_header.getColumnsHash() != local_part_header.getColumnsHash())
{
/// Currently there are two (known) cases when it may happen:
/// - KILL MUTATION query had removed mutation before all replicas have executed assigned MUTATE_PART entries.
/// Some replicas may skip this mutation and update part version without actually applying any changes.
/// It leads to mismatching checksum if changes were applied on other replicas.
/// - ALTER_METADATA and MERGE_PARTS were reordered on some replicas.
/// It may lead to different number of columns in merged parts on these replicas.
throw Exception(ErrorCodes::CHECKSUM_DOESNT_MATCH, "Part {} from {} has different columns hash "
"(it may rarely happen on race condition with KILL MUTATION or ALTER COLUMN).", part_name, replica);
}
replica_part_header.getChecksums().checkEqual(local_part_header.getChecksums(), true);
if (replica == replica_name)
has_been_already_added = true;
/// If we verify checksums in "sequential manner" (i.e. recheck absence of checksums on other replicas when commit)
/// then it is enough to verify checksums on at least one replica since checksums on other replicas must be the same.
if (absent_replicas_paths)
{
absent_replicas_paths->clear();
break;
}
}
if (!has_been_already_added)
{
const auto storage_settings_ptr = getSettings();
String part_path = fs::path(replica_path) / "parts" / part_name;
if (storage_settings_ptr->use_minimalistic_part_header_in_zookeeper)
{
ops.emplace_back(zkutil::makeCreateRequest(
part_path, local_part_header.toString(), zkutil::CreateMode::Persistent));
}
else
{
ops.emplace_back(zkutil::makeCreateRequest(
part_path, "", zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(part_path) / "columns", part->getColumns().toString(), zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(part_path) / "checksums", getChecksumsForZooKeeper(part->checksums), zkutil::CreateMode::Persistent));
}
}
else
{
LOG_WARNING(log, "checkPartAndAddToZooKeeper: node {} already exists. Will not commit any nodes.",
(fs::path(replica_path) / "parts" / part_name).string());
}
}
MergeTreeData::DataPartsVector StorageReplicatedMergeTree::checkPartChecksumsAndCommit(Transaction & transaction,
const DataPartPtr & part)
{
auto zookeeper = getZooKeeper();
while (true)
{
Coordination::Requests ops;
NameSet absent_part_paths_on_replicas;
/// Checksums are checked here and `ops` is filled. In fact, the part is added to ZK just below, when executing `multi`.
checkPartChecksumsAndAddCommitOps(zookeeper, part, ops, part->name, &absent_part_paths_on_replicas);
/// Do not commit if the part is obsolete, we have just briefly checked its checksums
if (transaction.isEmpty())
return {};
/// Will check that the part did not suddenly appear on skipped replicas
if (!absent_part_paths_on_replicas.empty())
{
Coordination::Requests new_ops;
for (const String & part_path : absent_part_paths_on_replicas)
{
/// NOTE Create request may fail with ZNONODE if replica is being dropped, we will throw an exception
new_ops.emplace_back(zkutil::makeCreateRequest(part_path, "", zkutil::CreateMode::Persistent));
new_ops.emplace_back(zkutil::makeRemoveRequest(part_path, -1));
}
/// Add check ops at the beginning
new_ops.insert(new_ops.end(), ops.begin(), ops.end());
ops = std::move(new_ops);
}
try
{
zookeeper->multi(ops);
return transaction.commit();
}
catch (const zkutil::KeeperMultiException & e)
{
size_t num_check_ops = 2 * absent_part_paths_on_replicas.size();
size_t failed_op_index = e.failed_op_index;
if (failed_op_index < num_check_ops && e.code == Coordination::Error::ZNODEEXISTS)
{
LOG_INFO(log, "The part {} on a replica suddenly appeared, will recheck checksums", e.getPathForFirstFailedOp());
}
else
throw;
}
}
}
String StorageReplicatedMergeTree::getChecksumsForZooKeeper(const MergeTreeDataPartChecksums & checksums) const
{
return MinimalisticDataPartChecksums::getSerializedString(checksums,
getSettings()->use_minimalistic_checksums_in_zookeeper);
}
MergeTreeData::MutableDataPartPtr StorageReplicatedMergeTree::attachPartHelperFoundValidPart(const LogEntry& entry) const
{
const MergeTreePartInfo actual_part_info = MergeTreePartInfo::fromPartName(entry.new_part_name, format_version);
const String part_new_name = actual_part_info.getPartName();
for (const DiskPtr & disk : getStoragePolicy()->getDisks())
for (const auto it = disk->iterateDirectory(fs::path(relative_data_path) / "detached/"); it->isValid(); it->next())
{
const auto part_info = MergeTreePartInfo::tryParsePartName(it->name(), format_version);
if (!part_info || part_info->partition_id != actual_part_info.partition_id)
continue;
const String part_old_name = part_info->getPartName();
const String part_path = fs::path("detached") / part_old_name;
const VolumePtr volume = std::make_shared<SingleDiskVolume>("volume_" + part_old_name, disk);
/// actual_part_info is more recent than part_info so we use it
MergeTreeData::MutableDataPartPtr part = createPart(part_new_name, actual_part_info, volume, part_path);
try
{
part->loadColumnsChecksumsIndexes(true, true);
}
catch (const Exception&)
{
/// This method throws if the part data is corrupted or partly missing. In this case, we simply don't
/// process the part.
continue;
}
if (entry.part_checksum == part->checksums.getTotalChecksumHex())
{
part->modification_time = disk->getLastModified(part->getFullRelativePath()).epochTime();
return part;
}
}
return {};
}
bool StorageReplicatedMergeTree::executeLogEntry(LogEntry & entry)
{
if (entry.type == LogEntry::DROP_RANGE)
{
executeDropRange(entry);
return true;
}
if (entry.type == LogEntry::REPLACE_RANGE)
{
executeReplaceRange(entry);
return true;
}
const bool is_get_or_attach = entry.type == LogEntry::GET_PART || entry.type == LogEntry::ATTACH_PART;
if (is_get_or_attach || entry.type == LogEntry::MERGE_PARTS || entry.type == LogEntry::MUTATE_PART)
{
/// If we already have this part or a part covering it, we do not need to do anything.
/// The part may be still in the PreActive -> Active transition so we first search
/// among PreActive parts to definitely find the desired part if it exists.
DataPartPtr existing_part = getPartIfExists(entry.new_part_name, {MergeTreeDataPartState::PreActive});
if (!existing_part)
existing_part = getActiveContainingPart(entry.new_part_name);
/// Even if the part is local, it (in exceptional cases) may not be in ZooKeeper. Let's check that it is there.
if (existing_part && getZooKeeper()->exists(fs::path(replica_path) / "parts" / existing_part->name))
{
if (!is_get_or_attach || entry.source_replica != replica_name)
LOG_DEBUG(log, "Skipping action for part {} because part {} already exists.",
entry.new_part_name, existing_part->name);
return true;
}
}
if (entry.type == LogEntry::ATTACH_PART)
{
if (MutableDataPartPtr part = attachPartHelperFoundValidPart(entry); part)
{
LOG_TRACE(log, "Found valid local part for {}, preparing the transaction", part->name);
Transaction transaction(*this);
renameTempPartAndReplace(part, nullptr, &transaction);
checkPartChecksumsAndCommit(transaction, part);
writePartLog(PartLogElement::Type::NEW_PART, {}, 0 /** log entry is fake so we don't measure the time */,
part->name, part, {} /** log entry is fake so there are no initial parts */, nullptr);
return true;
}
LOG_TRACE(log, "Didn't find valid local part for {} ({}), will fetch it from other replica",
entry.new_part_name,
entry.actual_new_part_name);
}
if (is_get_or_attach && entry.source_replica == replica_name)
LOG_WARNING(log, "Part {} from own log doesn't exist.", entry.new_part_name);
/// Perhaps we don't need this part, because during write with quorum, the quorum has failed
/// (see below about `/quorum/failed_parts`).
if (entry.quorum && getZooKeeper()->exists(fs::path(zookeeper_path) / "quorum" / "failed_parts" / entry.new_part_name))
{
LOG_DEBUG(log, "Skipping action for part {} because quorum for that part was failed.", entry.new_part_name);
return true; /// NOTE Deletion from `virtual_parts` is not done, but it is only necessary for merge.
}
// bool do_fetch = false;
switch (entry.type)
{
case LogEntry::ATTACH_PART:
/// We surely don't have this part locally as we've checked it before, so download it.
[[fallthrough]];
case LogEntry::GET_PART:
return executeFetch(entry);
// do_fetch = true;
case LogEntry::MERGE_PARTS:
throw Exception(ErrorCodes::LOGICAL_ERROR, "Merge has to be executed by another function");
case LogEntry::MUTATE_PART:
throw Exception(ErrorCodes::LOGICAL_ERROR, "Mutation has to be executed by another function");
case LogEntry::ALTER_METADATA:
return executeMetadataAlter(entry);
case LogEntry::SYNC_PINNED_PART_UUIDS:
syncPinnedPartUUIDs();
return true;
case LogEntry::CLONE_PART_FROM_SHARD:
executeClonePartFromShard(entry);
return true;
default:
throw Exception(ErrorCodes::LOGICAL_ERROR, "Unexpected log entry type: {}", static_cast<int>(entry.type));
}
// return true;
}
bool StorageReplicatedMergeTree::executeFetch(LogEntry & entry, bool need_to_check_missing_part)
{
/// Looking for covering part. After that entry.actual_new_part_name may be filled.
String replica = findReplicaHavingCoveringPart(entry, true);
const auto storage_settings_ptr = getSettings();
auto metadata_snapshot = getInMemoryMetadataPtr();
try
{
if (replica.empty())
{
/** If a part is to be written with a quorum and the quorum is not reached yet,
* then (due to the fact that a part is impossible to download right now),
* the quorum entry should be considered unsuccessful.
* TODO Complex code, extract separately.
*/
if (entry.quorum)
{
if (entry.type != LogEntry::GET_PART)
throw Exception("Logical error: log entry with quorum but type is not GET_PART", ErrorCodes::LOGICAL_ERROR);
LOG_DEBUG(log, "No active replica has part {} which needs to be written with quorum. Will try to mark that quorum as failed.", entry.new_part_name);
/** Atomically:
* - if replicas do not become active;
* - if there is a `quorum` node with this part;
* - delete `quorum` node;
* - add a part to the list `quorum/failed_parts`;
* - if the part is not already removed from the list for deduplication `blocks/block_num`, then delete it;
*
* If something changes, then we will nothing - we'll get here again next time.
*/
/** We collect the `host` node versions from the replicas.
* When the replica becomes active, it changes the value of host in the same transaction (with the creation of `is_active`).
* This will ensure that the replicas do not become active.
*/
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
Coordination::Requests ops;
for (const auto & path_part : replicas)
{
Coordination::Stat stat;
String path = fs::path(zookeeper_path) / "replicas" / path_part / "host";
zookeeper->get(path, &stat);
ops.emplace_back(zkutil::makeCheckRequest(path, stat.version));
}
/// We verify that while we were collecting versions, the replica with the necessary part did not come alive.
replica = findReplicaHavingPart(entry.new_part_name, true);
/// Also during this time a completely new replica could be created.
/// But if a part does not appear on the old, then it can not be on the new one either.
if (replica.empty())
{
Coordination::Stat quorum_stat;
const String quorum_unparallel_path = fs::path(zookeeper_path) / "quorum" / "status";
const String quorum_parallel_path = fs::path(zookeeper_path) / "quorum" / "parallel" / entry.new_part_name;
String quorum_str, quorum_path;
ReplicatedMergeTreeQuorumEntry quorum_entry;
if (zookeeper->tryGet(quorum_unparallel_path, quorum_str, &quorum_stat))
quorum_path = quorum_unparallel_path;
else
{
quorum_str = zookeeper->get(quorum_parallel_path, &quorum_stat);
quorum_path = quorum_parallel_path;
}
quorum_entry.fromString(quorum_str);
if (quorum_entry.part_name == entry.new_part_name)
{
ops.emplace_back(zkutil::makeRemoveRequest(quorum_path, quorum_stat.version));
auto part_info = MergeTreePartInfo::fromPartName(entry.new_part_name, format_version);
if (part_info.min_block != part_info.max_block)
throw Exception("Logical error: log entry with quorum for part covering more than one block number",
ErrorCodes::LOGICAL_ERROR);
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(zookeeper_path) / "quorum" / "failed_parts" / entry.new_part_name,
"",
zkutil::CreateMode::Persistent));
/// Deleting from `blocks`.
if (!entry.block_id.empty() && zookeeper->exists(fs::path(zookeeper_path) / "blocks" / entry.block_id))
ops.emplace_back(zkutil::makeRemoveRequest(fs::path(zookeeper_path) / "blocks" / entry.block_id, -1));
Coordination::Responses responses;
auto code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZOK)
{
LOG_DEBUG(log, "Marked quorum for part {} as failed.", entry.new_part_name);
queue.removeFailedQuorumPart(part_info);
return true;
}
else if (code == Coordination::Error::ZBADVERSION || code == Coordination::Error::ZNONODE || code == Coordination::Error::ZNODEEXISTS)
{
LOG_DEBUG(log, "State was changed or isn't expected when trying to mark quorum for part {} as failed. Code: {}",
entry.new_part_name, Coordination::errorMessage(code));
}
else
throw Coordination::Exception(code);
}
else
{
LOG_WARNING(log, "No active replica has part {}, "
"but that part needs quorum and /quorum/status contains entry about another part {}. "
"It means that part was successfully written to {} replicas, but then all of them goes offline. "
"Or it is a bug.", entry.new_part_name, quorum_entry.part_name, entry.quorum);
}
}
}
if (replica.empty())
{
ProfileEvents::increment(ProfileEvents::ReplicatedPartFailedFetches);
if (!need_to_check_missing_part)
return false;
throw Exception("No active replica has part " + entry.new_part_name + " or covering part", ErrorCodes::NO_REPLICA_HAS_PART);
}
}
try
{
String part_name = entry.actual_new_part_name.empty() ? entry.new_part_name : entry.actual_new_part_name;
if (!entry.actual_new_part_name.empty())
LOG_DEBUG(log, "Will fetch part {} instead of {}", entry.actual_new_part_name, entry.new_part_name);
if (!fetchPart(part_name, metadata_snapshot, fs::path(zookeeper_path) / "replicas" / replica, false, entry.quorum))
return false;
}
catch (Exception & e)
{
/// No stacktrace, just log message
if (e.code() == ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS)
e.addMessage("Too busy replica. Will try later.");
throw;
}
if (entry.type == LogEntry::MERGE_PARTS)
ProfileEvents::increment(ProfileEvents::ReplicatedPartFetchesOfMerged);
}
catch (...)
{
/** If we can not download the part we need for some merge, it's better not to try to get other parts for this merge,
* but try to get already merged part. To do this, move the action to get the remaining parts
* for this merge at the end of the queue.
*/
try
{
auto parts_for_merge = queue.moveSiblingPartsForMergeToEndOfQueue(entry.new_part_name);
if (!parts_for_merge.empty() && replica.empty())
{
LOG_INFO(log, "No active replica has part {}. Will fetch merged part instead.", entry.new_part_name);
/// We should enqueue it for check, because merged part may never appear if source part is lost
enqueuePartForCheck(entry.new_part_name);
return false;
}
/** If no active replica has a part, and there is no merge in the queue with its participation,
* check to see if any (active or inactive) replica has such a part or covering it.
*/
if (replica.empty())
enqueuePartForCheck(entry.new_part_name);
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
}
throw;
}
return true;
}
bool StorageReplicatedMergeTree::executeFetchShared(
const String & source_replica,
const String & new_part_name,
const DiskPtr & disk,
const String & path)
{
if (source_replica.empty())
{
LOG_INFO(log, "No active replica has part {} on shared storage.", new_part_name);
return false;
}
const auto storage_settings_ptr = getSettings();
auto metadata_snapshot = getInMemoryMetadataPtr();
try
{
if (!fetchExistsPart(new_part_name, metadata_snapshot, fs::path(zookeeper_path) / "replicas" / source_replica, disk, path))
return false;
}
catch (Exception & e)
{
if (e.code() == ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS)
e.addMessage("Too busy replica. Will try later.");
tryLogCurrentException(log, __PRETTY_FUNCTION__);
throw;
}
return true;
}
void StorageReplicatedMergeTree::executeDropRange(const LogEntry & entry)
{
LOG_TRACE(log, "Executing DROP_RANGE {}", entry.new_part_name);
auto drop_range_info = MergeTreePartInfo::fromPartName(entry.new_part_name, format_version);
getContext()->getMergeList().cancelInPartition(getStorageID(), drop_range_info.partition_id, drop_range_info.max_block);
part_check_thread.cancelRemovedPartsCheck(drop_range_info);
queue.removePartProducingOpsInRange(getZooKeeper(), drop_range_info, entry);
/// Delete the parts contained in the range to be deleted.
/// It's important that no old parts remain (after the merge), because otherwise,
/// after adding a new replica, this new replica downloads them, but does not delete them.
/// And, if you do not, the parts will come to life after the server is restarted.
/// Therefore, we use all data parts.
auto metadata_snapshot = getInMemoryMetadataPtr();
DataPartsVector parts_to_remove;
{
auto data_parts_lock = lockParts();
parts_to_remove = removePartsInRangeFromWorkingSet(drop_range_info, true, data_parts_lock);
if (parts_to_remove.empty())
{
if (!drop_range_info.isFakeDropRangePart())
LOG_INFO(log, "Log entry {} tried to drop single part {}, but part does not exist", entry.znode_name, entry.new_part_name);
return;
}
}
if (entry.detach)
LOG_DEBUG(log, "Detaching parts.");
else
LOG_DEBUG(log, "Removing parts.");
if (entry.detach)
{
/// If DETACH clone parts to detached/ directory
for (const auto & part : parts_to_remove)
{
LOG_INFO(log, "Detaching {}", part->relative_path);
part->makeCloneInDetached("", metadata_snapshot);
}
}
/// Forcibly remove parts from ZooKeeper
removePartsFromZooKeeperWithRetries(parts_to_remove);
if (entry.detach)
LOG_DEBUG(log, "Detached {} parts inside {}.", parts_to_remove.size(), entry.new_part_name);
else
LOG_DEBUG(log, "Removed {} parts inside {}.", parts_to_remove.size(), entry.new_part_name);
/// We want to remove dropped parts from disk as soon as possible
/// To be removed a partition should have zero refcount, therefore call the cleanup thread at exit
parts_to_remove.clear();
cleanup_thread.wakeup();
}
bool StorageReplicatedMergeTree::executeReplaceRange(const LogEntry & entry)
{
Stopwatch watch;
auto & entry_replace = *entry.replace_range_entry;
LOG_DEBUG(log, "Executing log entry {} to replace parts range {} with {} parts from {}.{}",
entry.znode_name, entry_replace.drop_range_part_name, entry_replace.new_part_names.size(),
entry_replace.from_database, entry_replace.from_table);
auto metadata_snapshot = getInMemoryMetadataPtr();
MergeTreePartInfo drop_range = MergeTreePartInfo::fromPartName(entry_replace.drop_range_part_name, format_version);
/// Range with only one block has special meaning: it's ATTACH PARTITION or MOVE PARTITION, so there is no drop range
bool replace = !LogEntry::ReplaceRangeEntry::isMovePartitionOrAttachFrom(drop_range);
if (replace)
{
getContext()->getMergeList().cancelInPartition(getStorageID(), drop_range.partition_id, drop_range.max_block);
part_check_thread.cancelRemovedPartsCheck(drop_range);
queue.removePartProducingOpsInRange(getZooKeeper(), drop_range, entry);
}
else
{
drop_range = {};
}
struct PartDescription
{
PartDescription(
size_t index_,
const String & src_part_name_,
const String & new_part_name_,
const String & checksum_hex_,
MergeTreeDataFormatVersion format_version)
: index(index_)
, src_part_name(src_part_name_)
, src_part_info(MergeTreePartInfo::fromPartName(src_part_name_, format_version))
, new_part_name(new_part_name_)
, new_part_info(MergeTreePartInfo::fromPartName(new_part_name_, format_version))
, checksum_hex(checksum_hex_)
{
}
size_t index; // in log entry arrays
String src_part_name;
MergeTreePartInfo src_part_info;
String new_part_name;
MergeTreePartInfo new_part_info;
String checksum_hex;
/// Part which will be committed
MutableDataPartPtr res_part;
/// We could find a covering part
MergeTreePartInfo found_new_part_info;
String found_new_part_name;
/// Hold pointer to part in source table if will clone it from local table
DataPartPtr src_table_part;
/// A replica that will be used to fetch part
String replica;
};
using PartDescriptionPtr = std::shared_ptr<PartDescription>;
using PartDescriptions = std::vector<PartDescriptionPtr>;
PartDescriptions all_parts;
PartDescriptions parts_to_add;
DataPartsVector parts_to_remove;
auto table_lock_holder_dst_table = lockForShare(
RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
auto dst_metadata_snapshot = getInMemoryMetadataPtr();
for (size_t i = 0; i < entry_replace.new_part_names.size(); ++i)
{
all_parts.emplace_back(std::make_shared<PartDescription>(i,
entry_replace.src_part_names.at(i),
entry_replace.new_part_names.at(i),
entry_replace.part_names_checksums.at(i),
format_version));
}
/// What parts we should add? Or we have already added all required parts (we an replica-initializer)
{
auto data_parts_lock = lockParts();
for (const PartDescriptionPtr & part_desc : all_parts)
{
if (!getActiveContainingPart(part_desc->new_part_info, MergeTreeDataPartState::Active, data_parts_lock))
parts_to_add.emplace_back(part_desc);
}
if (parts_to_add.empty() && replace)
{
parts_to_remove = removePartsInRangeFromWorkingSet(drop_range, true, data_parts_lock);
String parts_to_remove_str;
for (const auto & part : parts_to_remove)
{
parts_to_remove_str += part->name;
parts_to_remove_str += " ";
}
LOG_TRACE(log, "Replacing {} parts {}with empty set", parts_to_remove.size(), parts_to_remove_str);
}
}
if (parts_to_add.empty())
{
LOG_INFO(log, "All parts from REPLACE PARTITION command have been already attached");
removePartsFromZooKeeperWithRetries(parts_to_remove);
return true;
}
if (parts_to_add.size() < all_parts.size())
{
LOG_WARNING(log, "Some (but not all) parts from REPLACE PARTITION command already exist. REPLACE PARTITION will not be atomic.");
}
StoragePtr source_table;
TableLockHolder table_lock_holder_src_table;
StorageID source_table_id{entry_replace.from_database, entry_replace.from_table};
auto clone_data_parts_from_source_table = [&] () -> size_t
{
source_table = DatabaseCatalog::instance().tryGetTable(source_table_id, getContext());
if (!source_table)
{
LOG_DEBUG(log, "Can't use {} as source table for REPLACE PARTITION command. It does not exist.", source_table_id.getNameForLogs());
return 0;
}
auto src_metadata_snapshot = source_table->getInMemoryMetadataPtr();
MergeTreeData * src_data = nullptr;
try
{
src_data = &checkStructureAndGetMergeTreeData(source_table, src_metadata_snapshot, dst_metadata_snapshot);
}
catch (Exception &)
{
LOG_INFO(log, "Can't use {} as source table for REPLACE PARTITION command. Will fetch all parts. Reason: {}", source_table_id.getNameForLogs(), getCurrentExceptionMessage(false));
return 0;
}
table_lock_holder_src_table = source_table->lockForShare(
RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
DataPartStates valid_states{
MergeTreeDataPartState::PreActive, MergeTreeDataPartState::Active, MergeTreeDataPartState::Outdated};
size_t num_clonable_parts = 0;
for (PartDescriptionPtr & part_desc : parts_to_add)
{
auto src_part = src_data->getPartIfExists(part_desc->src_part_info, valid_states);
if (!src_part)
{
LOG_DEBUG(log, "There is no part {} in {}", part_desc->src_part_name, source_table_id.getNameForLogs());
continue;
}
String checksum_hex = src_part->checksums.getTotalChecksumHex();
if (checksum_hex != part_desc->checksum_hex)
{
LOG_DEBUG(log, "Part {} of {} has inappropriate checksum", part_desc->src_part_name, source_table_id.getNameForLogs());
/// TODO: check version
continue;
}
part_desc->found_new_part_name = part_desc->new_part_name;
part_desc->found_new_part_info = part_desc->new_part_info;
part_desc->src_table_part = src_part;
++num_clonable_parts;
}
return num_clonable_parts;
};
size_t num_clonable_parts = clone_data_parts_from_source_table();
LOG_DEBUG(log, "Found {} parts that could be cloned (of {} required parts)", num_clonable_parts, parts_to_add.size());
ActiveDataPartSet adding_parts_active_set(format_version);
std::unordered_map<String, PartDescriptionPtr> part_name_to_desc;
for (PartDescriptionPtr & part_desc : parts_to_add)
{
if (part_desc->src_table_part)
{
/// It is clonable part
adding_parts_active_set.add(part_desc->new_part_name);
part_name_to_desc.emplace(part_desc->new_part_name, part_desc);
continue;
}
/// Firstly, try find exact part to produce more accurate part set
String replica = findReplicaHavingPart(part_desc->new_part_name, true);
String found_part_name;
/// TODO: check version
if (replica.empty())
{
LOG_DEBUG(log, "Part {} is not found on remote replicas", part_desc->new_part_name);
/// Fallback to covering part
replica = findReplicaHavingCoveringPart(part_desc->new_part_name, true, found_part_name);
if (replica.empty())
{
/// It is not fail, since adjacent parts could cover current part
LOG_DEBUG(log, "Parts covering {} are not found on remote replicas", part_desc->new_part_name);
continue;
}
}
else
{
found_part_name = part_desc->new_part_name;
}
part_desc->found_new_part_name = found_part_name;
part_desc->found_new_part_info = MergeTreePartInfo::fromPartName(found_part_name, format_version);
part_desc->replica = replica;
adding_parts_active_set.add(part_desc->found_new_part_name);
part_name_to_desc.emplace(part_desc->found_new_part_name, part_desc);
}
/// Check that we could cover whole range
for (PartDescriptionPtr & part_desc : parts_to_add)
{
if (adding_parts_active_set.getContainingPart(part_desc->new_part_info).empty())
{
throw Exception("Not found part " + part_desc->new_part_name +
" (or part covering it) neither source table neither remote replicas" , ErrorCodes::NO_REPLICA_HAS_PART);
}
}
/// Filter covered parts
PartDescriptions final_parts;
Strings final_part_names;
{
final_part_names = adding_parts_active_set.getParts();
for (const String & final_part_name : final_part_names)
{
auto part_desc = part_name_to_desc[final_part_name];
if (!part_desc)
throw Exception("There is no final part " + final_part_name + ". This is a bug", ErrorCodes::LOGICAL_ERROR);
final_parts.emplace_back(part_desc);
if (final_parts.size() > 1)
{
auto & prev = *final_parts[final_parts.size() - 2];
auto & curr = *final_parts[final_parts.size() - 1];
if (!prev.found_new_part_info.isDisjoint(curr.found_new_part_info))
{
throw Exception("Intersected final parts detected: " + prev.found_new_part_name
+ " and " + curr.found_new_part_name + ". It should be investigated.", ErrorCodes::LOGICAL_ERROR);
}
}
}
}
static const String TMP_PREFIX = "tmp_replace_from_";
auto obtain_part = [&] (PartDescriptionPtr & part_desc)
{
if (part_desc->src_table_part)
{
if (part_desc->checksum_hex != part_desc->src_table_part->checksums.getTotalChecksumHex())
throw Exception("Checksums of " + part_desc->src_table_part->name + " is suddenly changed", ErrorCodes::UNFINISHED);
part_desc->res_part = cloneAndLoadDataPartOnSameDisk(
part_desc->src_table_part, TMP_PREFIX + "clone_", part_desc->new_part_info, metadata_snapshot);
}
else if (!part_desc->replica.empty())
{
String source_replica_path = fs::path(zookeeper_path) / "replicas" / part_desc->replica;
ReplicatedMergeTreeAddress address(getZooKeeper()->get(fs::path(source_replica_path) / "host"));
auto timeouts = getFetchPartHTTPTimeouts(getContext());
auto credentials = getContext()->getInterserverCredentials();
String interserver_scheme = getContext()->getInterserverScheme();
if (interserver_scheme != address.scheme)
throw Exception("Interserver schemas are different '" + interserver_scheme + "' != '" + address.scheme + "', can't fetch part from " + address.host, ErrorCodes::LOGICAL_ERROR);
part_desc->res_part = fetcher.fetchPart(
metadata_snapshot, getContext(), part_desc->found_new_part_name, source_replica_path,
address.host, address.replication_port, timeouts, credentials->getUser(), credentials->getPassword(),
interserver_scheme, replicated_fetches_throttler, false, TMP_PREFIX + "fetch_");
/// TODO: check columns_version of fetched part
ProfileEvents::increment(ProfileEvents::ReplicatedPartFetches);
}
else
throw Exception("There is no receipt to produce part " + part_desc->new_part_name + ". This is bug", ErrorCodes::LOGICAL_ERROR);
};
/// Download or clone parts
/// TODO: make it in parallel
for (PartDescriptionPtr & part_desc : final_parts)
obtain_part(part_desc);
MutableDataPartsVector res_parts;
for (PartDescriptionPtr & part_desc : final_parts)
res_parts.emplace_back(part_desc->res_part);
try
{
/// Commit parts
auto zookeeper = getZooKeeper();
Transaction transaction(*this);
Coordination::Requests ops;
for (PartDescriptionPtr & part_desc : final_parts)
{
renameTempPartAndReplace(part_desc->res_part, nullptr, &transaction);
getCommitPartOps(ops, part_desc->res_part);
}
if (!ops.empty())
zookeeper->multi(ops);
{
auto data_parts_lock = lockParts();
transaction.commit(&data_parts_lock);
if (replace)
{
parts_to_remove = removePartsInRangeFromWorkingSet(drop_range, true, data_parts_lock);
String parts_to_remove_str;
for (const auto & part : parts_to_remove)
{
parts_to_remove_str += part->name;
parts_to_remove_str += " ";
}
LOG_TRACE(log, "Replacing {} parts {}with {} parts {}", parts_to_remove.size(), parts_to_remove_str,
final_parts.size(), boost::algorithm::join(final_part_names, ", "));
}
}
PartLog::addNewParts(getContext(), res_parts, watch.elapsed());
}
catch (...)
{
PartLog::addNewParts(getContext(), res_parts, watch.elapsed(), ExecutionStatus::fromCurrentException());
throw;
}
removePartsFromZooKeeperWithRetries(parts_to_remove);
res_parts.clear();
parts_to_remove.clear();
cleanup_thread.wakeup();
return true;
}
void StorageReplicatedMergeTree::executeClonePartFromShard(const LogEntry & entry)
{
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(entry.source_shard + "/replicas");
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
String replica;
for (const String & candidate : replicas)
{
if (zookeeper->exists(entry.source_shard + "/replicas/" + candidate + "/is_active"))
{
replica = candidate;
break;
}
}
if (replica.empty())
throw Exception(ErrorCodes::NO_REPLICA_HAS_PART, "Not found active replica on shard {} to clone part {}", entry.source_shard, entry.new_part_name);
LOG_INFO(log, "Will clone part from shard {} and replica {}", entry.source_shard, replica);
MutableDataPartPtr part;
{
auto metadata_snapshot = getInMemoryMetadataPtr();
String source_replica_path = entry.source_shard + "/replicas/" + replica;
ReplicatedMergeTreeAddress address(getZooKeeper()->get(source_replica_path + "/host"));
auto timeouts = ConnectionTimeouts::getHTTPTimeouts(getContext());
auto credentials = getContext()->getInterserverCredentials();
String interserver_scheme = getContext()->getInterserverScheme();
auto get_part = [&, address, timeouts, credentials, interserver_scheme]()
{
if (interserver_scheme != address.scheme)
throw Exception("Interserver schemes are different: '" + interserver_scheme
+ "' != '" + address.scheme + "', can't fetch part from " + address.host,
ErrorCodes::LOGICAL_ERROR);
return fetcher.fetchPart(
metadata_snapshot, getContext(), entry.new_part_name, source_replica_path,
address.host, address.replication_port,
timeouts, credentials->getUser(), credentials->getPassword(), interserver_scheme,
replicated_fetches_throttler, true);
};
part = get_part();
// The fetched part is valuable and should not be cleaned like a temp part.
part->is_temp = false;
part->renameTo("detached/" + entry.new_part_name, true);
LOG_INFO(log, "Cloned part {} to detached directory", part->name);
}
}
void StorageReplicatedMergeTree::cloneReplica(const String & source_replica, Coordination::Stat source_is_lost_stat, zkutil::ZooKeeperPtr & zookeeper)
{
String source_path = fs::path(zookeeper_path) / "replicas" / source_replica;
/// The order of the following three actions is important.
Strings source_queue_names;
/// We are trying to get consistent /log_pointer and /queue state. Otherwise
/// we can possibly duplicate entries in queue of cloned replica.
while (true)
{
Coordination::Stat log_pointer_stat;
String raw_log_pointer = zookeeper->get(fs::path(source_path) / "log_pointer", &log_pointer_stat);
Coordination::Requests ops;
ops.push_back(zkutil::makeSetRequest(fs::path(replica_path) / "log_pointer", raw_log_pointer, -1));
/// For support old versions CH.
if (source_is_lost_stat.version == -1)
{
/// We check that it was not suddenly upgraded to new version.
/// Otherwise it can be upgraded and instantly become lost, but we cannot notice that.
ops.push_back(zkutil::makeCreateRequest(fs::path(source_path) / "is_lost", "0", zkutil::CreateMode::Persistent));
ops.push_back(zkutil::makeRemoveRequest(fs::path(source_path) / "is_lost", -1));
}
else /// The replica we clone should not suddenly become lost.
ops.push_back(zkutil::makeCheckRequest(fs::path(source_path) / "is_lost", source_is_lost_stat.version));
Coordination::Responses responses;
/// Let's remember the queue of the reference/master replica.
source_queue_names = zookeeper->getChildren(fs::path(source_path) / "queue");
/// Check that log pointer of source replica didn't changed while we read queue entries
ops.push_back(zkutil::makeCheckRequest(fs::path(source_path) / "log_pointer", log_pointer_stat.version));
auto rc = zookeeper->tryMulti(ops, responses);
if (rc == Coordination::Error::ZOK)
{
break;
}
else if (rc == Coordination::Error::ZNODEEXISTS)
{
throw Exception(
"Can not clone replica, because the " + source_replica + " updated to new ClickHouse version",
ErrorCodes::REPLICA_STATUS_CHANGED);
}
else if (responses[1]->error == Coordination::Error::ZBADVERSION)
{
/// If is_lost node version changed than source replica also lost,
/// so we cannot clone from it.
throw Exception(
"Can not clone replica, because the " + source_replica + " became lost", ErrorCodes::REPLICA_STATUS_CHANGED);
}
else if (responses.back()->error == Coordination::Error::ZBADVERSION)
{
/// If source replica's log_pointer changed than we probably read
/// stale state of /queue and have to try one more time.
LOG_WARNING(log, "Log pointer of source replica {} changed while we loading queue nodes. Will retry.", source_replica);
continue;
}
else
{
zkutil::KeeperMultiException::check(rc, ops, responses);
}
}
::sort(source_queue_names.begin(), source_queue_names.end());
struct QueueEntryInfo
{
String data = {};
Coordination::Stat stat = {};
LogEntryPtr parsed_entry = {};
};
/// We got log pointer and list of queue entries of source replica.
/// At first we will get queue entries and then we will get list of active parts of source replica
/// to enqueue fetches for missing parts. If source replica executes and removes some entry concurrently
/// we will see produced part (or covering part) in replicas/source/parts and will enqueue fetch.
/// We will try to parse queue entries before copying them
/// to avoid creation of excessive and duplicating entries in our queue.
/// See also removePartAndEnqueueFetch(...)
std::vector<QueueEntryInfo> source_queue;
ActiveDataPartSet get_part_set{format_version};
ActiveDataPartSet drop_range_set{format_version};
{
std::vector<zkutil::ZooKeeper::FutureGet> queue_get_futures;
queue_get_futures.reserve(source_queue_names.size());
for (const String & entry_name : source_queue_names)
queue_get_futures.push_back(zookeeper->asyncTryGet(fs::path(source_path) / "queue" / entry_name));
source_queue.reserve(source_queue_names.size());
for (size_t i = 0; i < source_queue_names.size(); ++i)
{
auto res = queue_get_futures[i].get();
/// It's ok if entry is already executed and removed: we also will get source parts set.
if (res.error == Coordination::Error::ZNONODE)
continue;
assert(res.error == Coordination::Error::ZOK);
source_queue.emplace_back();
auto & info = source_queue.back();
info.data = std::move(res.data);
info.stat = std::move(res.stat);
try
{
info.parsed_entry = LogEntry::parse(info.data, info.stat);
}
catch (...)
{
tryLogCurrentException(log, "Cannot parse source queue entry " + source_queue_names[i]);
}
/// It may be ok if source replica has newer version. We will copy entry as is.
if (!info.parsed_entry)
continue;
info.parsed_entry->znode_name = source_queue_names[i];
if (info.parsed_entry->type == LogEntry::DROP_RANGE)
drop_range_set.add(info.parsed_entry->new_part_name);
if (info.parsed_entry->type == LogEntry::GET_PART)
{
String maybe_covering_drop_range = drop_range_set.getContainingPart(info.parsed_entry->new_part_name);
if (maybe_covering_drop_range.empty())
get_part_set.add(info.parsed_entry->new_part_name);
}
}
}
/// We should do it after copying queue, because some ALTER_METADATA entries can be lost otherwise.
cloneMetadataIfNeeded(source_replica, source_path, zookeeper);
/// Add to the queue jobs to receive all the active parts that the reference/master replica has.
Strings source_replica_parts = zookeeper->getChildren(fs::path(source_path) / "parts");
for (const auto & active_part : source_replica_parts)
get_part_set.add(active_part);
Strings active_parts = get_part_set.getParts();
/// Remove local parts if source replica does not have them, because such parts will never be fetched by other replicas.
Strings local_parts_in_zk = zookeeper->getChildren(fs::path(replica_path) / "parts");
Strings parts_to_remove_from_zk;
for (const auto & part : local_parts_in_zk)
{
if (get_part_set.getContainingPart(part).empty())
{
parts_to_remove_from_zk.emplace_back(part);
LOG_WARNING(log, "Source replica does not have part {}. Removing it from ZooKeeper.", part);
}
}
{
/// Check "is_lost" version after retrieving queue and parts.
/// If version has changed, then replica most likely has been dropped and parts set is inconsistent,
/// so throw exception and retry cloning.
Coordination::Stat is_lost_stat_new;
zookeeper->get(fs::path(source_path) / "is_lost", &is_lost_stat_new);
if (is_lost_stat_new.version != source_is_lost_stat.version)
throw Exception(ErrorCodes::REPLICA_STATUS_CHANGED, "Cannot clone {}, because it suddenly become lost "
"or removed broken part from ZooKeeper", source_replica);
}
removePartsFromZooKeeperWithRetries(parts_to_remove_from_zk);
auto local_active_parts = getDataParts();
DataPartsVector parts_to_remove_from_working_set;
for (const auto & part : local_active_parts)
{
if (get_part_set.getContainingPart(part->name).empty())
{
parts_to_remove_from_working_set.emplace_back(part);
LOG_WARNING(log, "Source replica does not have part {}. Removing it from working set.", part->name);
}
}
if (getSettings()->detach_old_local_parts_when_cloning_replica)
{
auto metadata_snapshot = getInMemoryMetadataPtr();
for (const auto & part : parts_to_remove_from_working_set)
{
LOG_INFO(log, "Detaching {}", part->relative_path);
part->makeCloneInDetached("clone", metadata_snapshot);
}
}
removePartsFromWorkingSet(parts_to_remove_from_working_set, true);
std::unordered_set<String> created_get_parts;
/// Avoid creation of GET_PART entries which covered by another GET_PART or DROP_RANGE
/// and creation of multiple entries with the same new_part_name.
auto should_ignore_log_entry = [&drop_range_set, &get_part_set, this] (std::unordered_set<String> & created_gets,
const String & part_name, const String & log_msg_context) -> bool
{
/// We should not create entries covered by DROP_RANGE, because we will remove them anyway (kind of optimization).
String covering_drop_range = drop_range_set.getContainingPart(part_name);
if (!covering_drop_range.empty())
{
LOG_TRACE(log, "{} {}: it's covered by DROP_RANGE {}", log_msg_context, part_name, covering_drop_range);
return true;
}
/// We should not create entries covered by GET_PART,
/// because GET_PART entry has no source parts and we can execute it only by fetching.
/// Parts covered by GET_PART are useless and may cause replication to stuck if covered part is lost.
String covering_get_part_entry = get_part_set.getContainingPart(part_name);
if (covering_get_part_entry.empty())
return false;
if (covering_get_part_entry != part_name)
{
LOG_TRACE(log, "{} {}: it's covered by GET_PART {}", log_msg_context, part_name, covering_get_part_entry);
return true;
}
/// NOTE: It does not completely avoids duplication of GET_PART entries,
/// because it's possible that source replica has executed some GET_PART after we copied it's queue,
/// but before we copied its active parts set. In this case we will GET_PART entry in our queue
/// and later will pull the original GET_PART from replication log.
/// It should not cause any issues, but it does not allow to get rid of duplicated entries and add an assertion.
if (created_gets.count(part_name))
{
/// NOTE It would be better to copy log entry instead of creating GET_PART
/// if there are GET_PART and log entry of other type with the same new_part_name.
/// But it's a bit harder to implement, because it requires full-fledged virtual_parts set.
LOG_TRACE(log, "{} {}: GET_PART for it is already created", log_msg_context, part_name);
return true;
}
return false;
};
for (const String & name : active_parts)
{
if (should_ignore_log_entry(created_get_parts, name, "Not fetching"))
continue;
LogEntry log_entry;
if (are_restoring_replica)
{
LOG_DEBUG(log, "Obtaining checksum for path {}", name);
// The part we want to fetch is probably present in detached/ folder.
// However, we need to get part's checksum to check if it's not corrupt.
log_entry.type = LogEntry::ATTACH_PART;
MinimalisticDataPartChecksums desired_checksums;
const fs::path part_path = fs::path(source_path) / "parts" / name;
const String part_znode = zookeeper->get(part_path);
if (!part_znode.empty())
desired_checksums = ReplicatedMergeTreePartHeader::fromString(part_znode).getChecksums();
else
{
String desired_checksums_str = zookeeper->get(part_path / "checksums");
desired_checksums = MinimalisticDataPartChecksums::deserializeFrom(desired_checksums_str);
}
const auto [lo, hi] = desired_checksums.hash_of_all_files;
log_entry.part_checksum = getHexUIntUppercase(hi) + getHexUIntUppercase(lo);
}
else
{
log_entry.type = LogEntry::GET_PART;
}
log_entry.source_replica = "";
log_entry.new_part_name = name;
log_entry.create_time = tryGetPartCreateTime(zookeeper, source_path, name);
LOG_TEST(log, "Enqueueing {} for fetch", name);
zookeeper->create(fs::path(replica_path) / "queue/queue-", log_entry.toString(), zkutil::CreateMode::PersistentSequential);
created_get_parts.insert(name);
}
size_t total_parts_to_fetch = created_get_parts.size();
LOG_DEBUG(log, "Queued {} parts to be fetched, {} parts ignored", total_parts_to_fetch, active_parts.size() - total_parts_to_fetch);
/// Add content of the reference/master replica queue to the queue.
size_t total_entries_to_copy = 0;
for (const auto & entry_info : source_queue)
{
assert(!entry_info.data.empty());
if (entry_info.parsed_entry && !entry_info.parsed_entry->new_part_name.empty())
{
const String & part_name = entry_info.parsed_entry->new_part_name;
const String & entry_name = entry_info.parsed_entry->znode_name;
const auto & entry_type = entry_info.parsed_entry->type;
if (should_ignore_log_entry(created_get_parts, part_name, fmt::format("Not copying {} {} ", entry_name, entry_type)))
continue;
if (entry_info.parsed_entry->type == LogEntry::GET_PART)
created_get_parts.insert(part_name);
}
LOG_TEST(log, "Copying entry {}", entry_info.data);
zookeeper->create(fs::path(replica_path) / "queue/queue-", entry_info.data, zkutil::CreateMode::PersistentSequential);
++total_entries_to_copy;
}
LOG_DEBUG(log, "Copied {} queue entries, {} entries ignored", total_entries_to_copy, source_queue.size() - total_entries_to_copy);
}
void StorageReplicatedMergeTree::cloneMetadataIfNeeded(const String & source_replica, const String & source_path, zkutil::ZooKeeperPtr & zookeeper)
{
String source_metadata_version_str;
bool metadata_version_exists = zookeeper->tryGet(source_path + "/metadata_version", source_metadata_version_str);
if (!metadata_version_exists)
{
/// For compatibility with version older than 20.3
/// TODO fix tests and delete it
LOG_WARNING(log, "Node {} does not exist. "
"Most likely it's because too old version of ClickHouse is running on replica {}. "
"Will not check metadata consistency",
source_path + "/metadata_version", source_replica);
return;
}
Int32 source_metadata_version = parse<Int32>(source_metadata_version_str);
if (metadata_version == source_metadata_version)
return;
/// Our metadata it not up to date with source replica metadata.
/// Metadata is updated by ALTER_METADATA entries, but some entries are probably cleaned up from the log.
/// It's also possible that some newer ALTER_METADATA entries are present in source_queue list,
/// and source replica are executing such entry right now (or had executed recently).
/// More than that, /metadata_version update is not atomic with /columns and /metadata update...
/// Fortunately, ALTER_METADATA seems to be idempotent,
/// and older entries of such type can be replaced with newer entries.
/// Let's try to get consistent values of source replica's /columns and /metadata
/// and prepend dummy ALTER_METADATA to our replication queue.
/// It should not break anything if source_queue already contains ALTER_METADATA entry
/// with greater or equal metadata_version, but it will update our metadata
/// if all such entries were cleaned up from the log and source_queue.
LOG_WARNING(log, "Metadata version ({}) on replica is not up to date with metadata ({}) on source replica {}",
metadata_version, source_metadata_version, source_replica);
String source_metadata;
String source_columns;
while (true)
{
Coordination::Stat metadata_stat;
Coordination::Stat columns_stat;
source_metadata = zookeeper->get(source_path + "/metadata", &metadata_stat);
source_columns = zookeeper->get(source_path + "/columns", &columns_stat);
Coordination::Requests ops;
Coordination::Responses responses;
ops.emplace_back(zkutil::makeCheckRequest(source_path + "/metadata", metadata_stat.version));
ops.emplace_back(zkutil::makeCheckRequest(source_path + "/columns", columns_stat.version));
Coordination::Error code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZOK)
break;
else if (code == Coordination::Error::ZBADVERSION)
LOG_WARNING(log, "Metadata of replica {} was changed", source_path);
else
zkutil::KeeperMultiException::check(code, ops, responses);
}
ReplicatedMergeTreeLogEntryData dummy_alter;
dummy_alter.type = LogEntry::ALTER_METADATA;
dummy_alter.source_replica = source_replica;
dummy_alter.metadata_str = source_metadata;
dummy_alter.columns_str = source_columns;
dummy_alter.alter_version = source_metadata_version;
dummy_alter.create_time = time(nullptr);
zookeeper->create(replica_path + "/queue/queue-", dummy_alter.toString(), zkutil::CreateMode::PersistentSequential);
/// We don't need to do anything with mutation_pointer, because mutation log cleanup process is different from
/// replication log cleanup. A mutation is removed from ZooKeeper only if all replicas had executed the mutation,
/// so all mutations which are greater or equal to our mutation pointer are still present in ZooKeeper.
}
void StorageReplicatedMergeTree::cloneReplicaIfNeeded(zkutil::ZooKeeperPtr zookeeper)
{
Coordination::Stat is_lost_stat;
bool is_new_replica = true;
String res;
if (zookeeper->tryGet(fs::path(replica_path) / "is_lost", res, &is_lost_stat))
{
if (res == "0")
return;
if (is_lost_stat.version)
is_new_replica = false;
}
else
{
/// Replica was created by old version of CH, so me must create "/is_lost".
/// Note that in old version of CH there was no "lost" replicas possible.
/// TODO is_lost node should always exist since v18.12, maybe we can replace `tryGet` with `get` and remove old code?
zookeeper->create(fs::path(replica_path) / "is_lost", "0", zkutil::CreateMode::Persistent);
return;
}
/// is_lost is "1": it means that we are in repair mode.
/// Try choose source replica to clone.
/// Source replica must not be lost and should have minimal queue size and maximal log pointer.
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
std::vector<zkutil::ZooKeeper::FutureGet> futures;
for (const String & source_replica_name : replicas)
{
/// Do not clone from myself.
if (source_replica_name == replica_name)
continue;
String source_replica_path = fs::path(zookeeper_path) / "replicas" / source_replica_name;
/// Obviously the following get operations are not atomic, but it's ok to choose good enough replica, not the best one.
/// NOTE: We may count some entries twice if log_pointer is moved.
futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "is_lost"));
futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "log_pointer"));
futures.emplace_back(zookeeper->asyncTryGet(fs::path(source_replica_path) / "queue"));
}
/// Wait for results before getting log entries
for (auto & future : futures)
future.wait();
Strings log_entries = zookeeper->getChildren(fs::path(zookeeper_path) / "log");
size_t max_log_entry = 0;
if (!log_entries.empty())
{
String last_entry = *std::max_element(log_entries.begin(), log_entries.end());
max_log_entry = parse<UInt64>(last_entry.substr(strlen("log-")));
}
/// log_pointer can point to future entry, which was not created yet
++max_log_entry;
size_t min_replication_lag = std::numeric_limits<size_t>::max();
String source_replica;
Coordination::Stat source_is_lost_stat;
size_t future_num = 0;
for (const String & source_replica_name : replicas)
{
if (source_replica_name == replica_name)
continue;
auto get_is_lost = futures[future_num++].get();
auto get_log_pointer = futures[future_num++].get();
auto get_queue = futures[future_num++].get();
if (get_is_lost.error != Coordination::Error::ZOK)
{
LOG_INFO(log, "Not cloning {}, cannot get '/is_lost': {}", source_replica_name, Coordination::errorMessage(get_is_lost.error));
continue;
}
else if (get_is_lost.data != "0")
{
LOG_INFO(log, "Not cloning {}, it's lost", source_replica_name);
continue;
}
if (get_log_pointer.error != Coordination::Error::ZOK)
{
LOG_INFO(log, "Not cloning {}, cannot get '/log_pointer': {}", source_replica_name, Coordination::errorMessage(get_log_pointer.error));
continue;
}
if (get_queue.error != Coordination::Error::ZOK)
{
LOG_INFO(log, "Not cloning {}, cannot get '/queue': {}", source_replica_name, Coordination::errorMessage(get_queue.error));
continue;
}
/// Replica is not lost and we can clone it. Let's calculate approx replication lag.
size_t source_log_pointer = get_log_pointer.data.empty() ? 0 : parse<UInt64>(get_log_pointer.data);
assert(source_log_pointer <= max_log_entry);
size_t replica_queue_lag = max_log_entry - source_log_pointer;
size_t replica_queue_size = get_queue.stat.numChildren;
size_t replication_lag = replica_queue_lag + replica_queue_size;
LOG_INFO(log, "Replica {} has log pointer '{}', approximate {} queue lag and {} queue size",
source_replica_name, get_log_pointer.data, replica_queue_lag, replica_queue_size);
if (replication_lag < min_replication_lag)
{
source_replica = source_replica_name;
source_is_lost_stat = get_is_lost.stat;
min_replication_lag = replication_lag;
}
}
if (source_replica.empty())
throw Exception("All replicas are lost", ErrorCodes::ALL_REPLICAS_LOST);
if (is_new_replica)
LOG_INFO(log, "Will mimic {}", source_replica);
else
LOG_WARNING(log, "Will mimic {}", source_replica);
/// Clear obsolete queue that we no longer need.
zookeeper->removeChildren(fs::path(replica_path) / "queue");
queue.clear();
/// Will do repair from the selected replica.
cloneReplica(source_replica, source_is_lost_stat, zookeeper);
/// If repair fails to whatever reason, the exception is thrown, is_lost will remain "1" and the replica will be repaired later.
/// If replica is repaired successfully, we remove is_lost flag.
zookeeper->set(fs::path(replica_path) / "is_lost", "0");
}
String StorageReplicatedMergeTree::getLastQueueUpdateException() const
{
std::unique_lock lock(last_queue_update_exception_lock);
return last_queue_update_exception;
}
void StorageReplicatedMergeTree::queueUpdatingTask()
{
if (!queue_update_in_progress)
{
last_queue_update_start_time.store(time(nullptr));
queue_update_in_progress = true;
}
try
{
queue.pullLogsToQueue(getZooKeeperAndAssertNotReadonly(), queue_updating_task->getWatchCallback(), ReplicatedMergeTreeQueue::UPDATE);
last_queue_update_finish_time.store(time(nullptr));
queue_update_in_progress = false;
}
catch (const Coordination::Exception & e)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
std::unique_lock lock(last_queue_update_exception_lock);
last_queue_update_exception = getCurrentExceptionMessage(false);
if (e.code == Coordination::Error::ZSESSIONEXPIRED)
{
restarting_thread.wakeup();
return;
}
queue_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
std::unique_lock lock(last_queue_update_exception_lock);
last_queue_update_exception = getCurrentExceptionMessage(false);
queue_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
}
}
void StorageReplicatedMergeTree::mutationsUpdatingTask()
{
try
{
queue.updateMutations(getZooKeeper(), mutations_updating_task->getWatchCallback());
}
catch (const Coordination::Exception & e)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
if (e.code == Coordination::Error::ZSESSIONEXPIRED)
return;
mutations_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
mutations_updating_task->scheduleAfter(QUEUE_UPDATE_ERROR_SLEEP_MS);
}
}
ReplicatedMergeTreeQueue::SelectedEntryPtr StorageReplicatedMergeTree::selectQueueEntry()
{
/// This object will mark the element of the queue as running.
ReplicatedMergeTreeQueue::SelectedEntryPtr selected;
try
{
selected = queue.selectEntryToProcess(merger_mutator, *this);
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
}
return selected;
}
bool StorageReplicatedMergeTree::processQueueEntry(ReplicatedMergeTreeQueue::SelectedEntryPtr selected_entry)
{
LogEntryPtr & entry = selected_entry->log_entry;
return queue.processEntry([this]{ return getZooKeeper(); }, entry, [&](LogEntryPtr & entry_to_process)
{
try
{
return executeLogEntry(*entry_to_process);
}
catch (const Exception & e)
{
if (e.code() == ErrorCodes::NO_REPLICA_HAS_PART)
{
/// If no one has the right part, probably not all replicas work; We will not write to log with Error level.
LOG_INFO(log, fmt::runtime(e.displayText()));
}
else if (e.code() == ErrorCodes::ABORTED)
{
/// Interrupted merge or downloading a part is not an error.
LOG_INFO(log, fmt::runtime(e.message()));
}
else if (e.code() == ErrorCodes::PART_IS_TEMPORARILY_LOCKED)
{
/// Part cannot be added temporarily
LOG_INFO(log, fmt::runtime(e.displayText()));
cleanup_thread.wakeup();
}
else
tryLogCurrentException(log, __PRETTY_FUNCTION__);
/** This exception will be written to the queue element, and it can be looked up using `system.replication_queue` table.
* The thread that performs this action will sleep a few seconds after the exception.
* See `queue.processEntry` function.
*/
throw;
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
throw;
}
});
}
bool StorageReplicatedMergeTree::scheduleDataProcessingJob(BackgroundJobsAssignee & assignee)
{
/// If replication queue is stopped exit immediately as we successfully executed the task
if (queue.actions_blocker.isCancelled())
return false;
/// This object will mark the element of the queue as running.
ReplicatedMergeTreeQueue::SelectedEntryPtr selected_entry = selectQueueEntry();
if (!selected_entry)
return false;
auto job_type = selected_entry->log_entry->type;
/// Depending on entry type execute in fetches (small) pool or big merge_mutate pool
if (job_type == LogEntry::GET_PART)
{
assignee.scheduleFetchTask(ExecutableLambdaAdapter::create(
[this, selected_entry] () mutable
{
return processQueueEntry(selected_entry);
}, common_assignee_trigger, getStorageID()));
return true;
}
else if (job_type == LogEntry::MERGE_PARTS)
{
auto task = MergeFromLogEntryTask::create(selected_entry, *this, common_assignee_trigger);
assignee.scheduleMergeMutateTask(task);
return true;
}
else if (job_type == LogEntry::MUTATE_PART)
{
auto task = MutateFromLogEntryTask::create(selected_entry, *this, common_assignee_trigger);
assignee.scheduleMergeMutateTask(task);
return true;
}
else
{
assignee.scheduleCommonTask(ExecutableLambdaAdapter::create(
[this, selected_entry] () mutable
{
return processQueueEntry(selected_entry);
}, common_assignee_trigger, getStorageID()), /* need_trigger */ true);
return true;
}
}
bool StorageReplicatedMergeTree::canExecuteFetch(const ReplicatedMergeTreeLogEntry & entry, String & disable_reason) const
{
if (fetcher.blocker.isCancelled())
{
disable_reason = fmt::format("Not executing fetch of part {} because replicated fetches are cancelled now.", entry.new_part_name);
return false;
}
size_t busy_threads_in_pool = CurrentMetrics::values[CurrentMetrics::BackgroundFetchesPoolTask].load(std::memory_order_relaxed);
if (busy_threads_in_pool >= replicated_fetches_pool_size)
{
disable_reason = fmt::format("Not executing fetch of part {} because {} fetches already executing, max {}.", entry.new_part_name, busy_threads_in_pool, replicated_fetches_pool_size);
return false;
}
if (replicated_fetches_throttler->isThrottling())
{
disable_reason = fmt::format("Not executing fetch of part {} because fetches have already throttled by network settings "
"<max_replicated_fetches_network_bandwidth> or <max_replicated_fetches_network_bandwidth_for_server>.", entry.new_part_name);
return false;
}
return true;
}
bool StorageReplicatedMergeTree::partIsAssignedToBackgroundOperation(const DataPartPtr & part) const
{
return queue.isVirtualPart(part);
}
void StorageReplicatedMergeTree::mergeSelectingTask()
{
if (!is_leader)
return;
const auto storage_settings_ptr = getSettings();
const bool deduplicate = false; /// TODO: read deduplicate option from table config
const Names deduplicate_by_columns = {};
CreateMergeEntryResult create_result = CreateMergeEntryResult::Other;
try
{
/// We must select parts for merge under merge_selecting_mutex because other threads
/// (OPTIMIZE queries) can assign new merges.
std::lock_guard merge_selecting_lock(merge_selecting_mutex);
auto zookeeper = getZooKeeperAndAssertNotReadonly();
ReplicatedMergeTreeMergePredicate merge_pred = queue.getMergePredicate(zookeeper);
/// If many merges is already queued, then will queue only small enough merges.
/// Otherwise merge queue could be filled with only large merges,
/// and in the same time, many small parts could be created and won't be merged.
auto merges_and_mutations_queued = queue.countMergesAndPartMutations();
size_t merges_and_mutations_sum = merges_and_mutations_queued.merges + merges_and_mutations_queued.mutations;
if (merges_and_mutations_sum >= storage_settings_ptr->max_replicated_merges_in_queue)
{
LOG_TRACE(log, "Number of queued merges ({}) and part mutations ({})"
" is greater than max_replicated_merges_in_queue ({}), so won't select new parts to merge or mutate.",
merges_and_mutations_queued.merges,
merges_and_mutations_queued.mutations,
storage_settings_ptr->max_replicated_merges_in_queue);
}
else
{
UInt64 max_source_parts_size_for_merge = merger_mutator.getMaxSourcePartsSizeForMerge(
storage_settings_ptr->max_replicated_merges_in_queue, merges_and_mutations_sum);
UInt64 max_source_part_size_for_mutation = merger_mutator.getMaxSourcePartSizeForMutation();
bool merge_with_ttl_allowed = merges_and_mutations_queued.merges_with_ttl < storage_settings_ptr->max_replicated_merges_with_ttl_in_queue &&
getTotalMergesWithTTLInMergeList() < storage_settings_ptr->max_number_of_merges_with_ttl_in_pool;
auto future_merged_part = std::make_shared<FutureMergedMutatedPart>();
if (storage_settings.get()->assign_part_uuids)
future_merged_part->uuid = UUIDHelpers::generateV4();
if (max_source_parts_size_for_merge > 0 &&
merger_mutator.selectPartsToMerge(future_merged_part, false, max_source_parts_size_for_merge, merge_pred, merge_with_ttl_allowed, nullptr) == SelectPartsDecision::SELECTED)
{
create_result = createLogEntryToMergeParts(
zookeeper,
future_merged_part->parts,
future_merged_part->name,
future_merged_part->uuid,
future_merged_part->type,
deduplicate,
deduplicate_by_columns,
nullptr,
merge_pred.getVersion(),
future_merged_part->merge_type);
}
/// If there are many mutations in queue, it may happen, that we cannot enqueue enough merges to merge all new parts
else if (max_source_part_size_for_mutation > 0 && queue.countMutations() > 0
&& merges_and_mutations_queued.mutations < storage_settings_ptr->max_replicated_mutations_in_queue)
{
/// Choose a part to mutate.
DataPartsVector data_parts = getDataPartsVector();
for (const auto & part : data_parts)
{
if (part->getBytesOnDisk() > max_source_part_size_for_mutation)
continue;
std::optional<std::pair<Int64, int>> desired_mutation_version = merge_pred.getDesiredMutationVersion(part);
if (!desired_mutation_version)
continue;
create_result = createLogEntryToMutatePart(
*part,
future_merged_part->uuid,
desired_mutation_version->first,
desired_mutation_version->second,
merge_pred.getVersion());
if (create_result == CreateMergeEntryResult::Ok ||
create_result == CreateMergeEntryResult::LogUpdated)
break;
}
}
}
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
}
if (!is_leader)
return;
if (create_result != CreateMergeEntryResult::Ok
&& create_result != CreateMergeEntryResult::LogUpdated)
{
merge_selecting_task->scheduleAfter(storage_settings_ptr->merge_selecting_sleep_ms);
}
else
{
merge_selecting_task->schedule();
}
}
void StorageReplicatedMergeTree::mutationsFinalizingTask()
{
bool needs_reschedule = false;
try
{
needs_reschedule = queue.tryFinalizeMutations(getZooKeeperAndAssertNotReadonly());
}
catch (...)
{
tryLogCurrentException(log, __PRETTY_FUNCTION__);
needs_reschedule = true;
}
if (needs_reschedule)
{
mutations_finalizing_task->scheduleAfter(MUTATIONS_FINALIZING_SLEEP_MS);
}
else
{
/// Even if no mutations seems to be done or appeared we are trying to
/// finalize them in background because manual control the launch of
/// this function is error prone. This can lead to mutations that
/// processed all the parts but have is_done=0 state for a long time. Or
/// killed mutations, which are also considered as undone.
mutations_finalizing_task->scheduleAfter(MUTATIONS_FINALIZING_IDLE_SLEEP_MS);
}
}
StorageReplicatedMergeTree::CreateMergeEntryResult StorageReplicatedMergeTree::createLogEntryToMergeParts(
zkutil::ZooKeeperPtr & zookeeper,
const DataPartsVector & parts,
const String & merged_name,
const UUID & merged_part_uuid,
const MergeTreeDataPartType & merged_part_type,
bool deduplicate,
const Names & deduplicate_by_columns,
ReplicatedMergeTreeLogEntryData * out_log_entry,
int32_t log_version,
MergeType merge_type)
{
std::vector<std::future<Coordination::ExistsResponse>> exists_futures;
exists_futures.reserve(parts.size());
for (const auto & part : parts)
exists_futures.emplace_back(zookeeper->asyncExists(fs::path(replica_path) / "parts" / part->name));
bool all_in_zk = true;
for (size_t i = 0; i < parts.size(); ++i)
{
/// If there is no information about part in ZK, we will not merge it.
if (exists_futures[i].get().error == Coordination::Error::ZNONODE)
{
all_in_zk = false;
const auto & part = parts[i];
if (part->modification_time + MAX_AGE_OF_LOCAL_PART_THAT_WASNT_ADDED_TO_ZOOKEEPER < time(nullptr))
{
LOG_WARNING(log, "Part {} (that was selected for merge) with age {} seconds exists locally but not in ZooKeeper. Won't do merge with that part and will check it.", part->name, (time(nullptr) - part->modification_time));
enqueuePartForCheck(part->name);
}
}
}
if (!all_in_zk)
return CreateMergeEntryResult::MissingPart;
ReplicatedMergeTreeLogEntryData entry;
entry.type = LogEntry::MERGE_PARTS;
entry.source_replica = replica_name;
entry.new_part_name = merged_name;
entry.new_part_uuid = merged_part_uuid;
entry.new_part_type = merged_part_type;
entry.merge_type = merge_type;
entry.deduplicate = deduplicate;
entry.deduplicate_by_columns = deduplicate_by_columns;
entry.create_time = time(nullptr);
for (const auto & part : parts)
entry.source_parts.push_back(part->name);
Coordination::Requests ops;
Coordination::Responses responses;
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(zookeeper_path) / "log/log-", entry.toString(),
zkutil::CreateMode::PersistentSequential));
ops.emplace_back(zkutil::makeSetRequest(
fs::path(zookeeper_path) / "log", "", log_version)); /// Check and update version.
Coordination::Error code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZOK)
{
String path_created = dynamic_cast<const Coordination::CreateResponse &>(*responses.front()).path_created;
entry.znode_name = path_created.substr(path_created.find_last_of('/') + 1);
ProfileEvents::increment(ProfileEvents::CreatedLogEntryForMerge);
LOG_TRACE(log, "Created log entry {} for merge {}", path_created, merged_name);
}
else if (code == Coordination::Error::ZBADVERSION)
{
ProfileEvents::increment(ProfileEvents::NotCreatedLogEntryForMerge);
LOG_TRACE(log, "Log entry is not created for merge {} because log was updated", merged_name);
return CreateMergeEntryResult::LogUpdated;
}
else
{
zkutil::KeeperMultiException::check(code, ops, responses);
}
if (out_log_entry)
*out_log_entry = entry;
return CreateMergeEntryResult::Ok;
}
StorageReplicatedMergeTree::CreateMergeEntryResult StorageReplicatedMergeTree::createLogEntryToMutatePart(
const IMergeTreeDataPart & part, const UUID & new_part_uuid, Int64 mutation_version, int32_t alter_version, int32_t log_version)
{
auto zookeeper = getZooKeeper();
/// If there is no information about part in ZK, we will not mutate it.
if (!zookeeper->exists(fs::path(replica_path) / "parts" / part.name))
{
if (part.modification_time + MAX_AGE_OF_LOCAL_PART_THAT_WASNT_ADDED_TO_ZOOKEEPER < time(nullptr))
{
LOG_WARNING(log, "Part {} (that was selected for mutation) with age {} seconds exists locally but not in ZooKeeper."
" Won't mutate that part and will check it.", part.name, (time(nullptr) - part.modification_time));
enqueuePartForCheck(part.name);
}
return CreateMergeEntryResult::MissingPart;
}
MergeTreePartInfo new_part_info = part.info;
new_part_info.mutation = mutation_version;
String new_part_name = part.getNewName(new_part_info);
ReplicatedMergeTreeLogEntryData entry;
entry.type = LogEntry::MUTATE_PART;
entry.source_replica = replica_name;
entry.source_parts.push_back(part.name);
entry.new_part_name = new_part_name;
entry.new_part_uuid = new_part_uuid;
entry.create_time = time(nullptr);
entry.alter_version = alter_version;
Coordination::Requests ops;
Coordination::Responses responses;
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(zookeeper_path) / "log/log-", entry.toString(),
zkutil::CreateMode::PersistentSequential));
ops.emplace_back(zkutil::makeSetRequest(
fs::path(zookeeper_path) / "log", "", log_version)); /// Check and update version.
Coordination::Error code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZBADVERSION)
{
ProfileEvents::increment(ProfileEvents::NotCreatedLogEntryForMutation);
LOG_TRACE(log, "Log entry is not created for mutation {} because log was updated", new_part_name);
return CreateMergeEntryResult::LogUpdated;
}
zkutil::KeeperMultiException::check(code, ops, responses);
ProfileEvents::increment(ProfileEvents::CreatedLogEntryForMutation);
LOG_TRACE(log, "Created log entry for mutation {}", new_part_name);
return CreateMergeEntryResult::Ok;
}
void StorageReplicatedMergeTree::removePartFromZooKeeper(const String & part_name, Coordination::Requests & ops, bool has_children)
{
String part_path = fs::path(replica_path) / "parts" / part_name;
if (has_children)
{
ops.emplace_back(zkutil::makeRemoveRequest(fs::path(part_path) / "checksums", -1));
ops.emplace_back(zkutil::makeRemoveRequest(fs::path(part_path) / "columns", -1));
}
ops.emplace_back(zkutil::makeRemoveRequest(part_path, -1));
}
void StorageReplicatedMergeTree::removePartFromZooKeeper(const String & part_name)
{
auto zookeeper = getZooKeeper();
String part_path = fs::path(replica_path) / "parts" / part_name;
Coordination::Stat stat;
/// Part doesn't exist, nothing to remove
if (!zookeeper->exists(part_path, &stat))
return;
Coordination::Requests ops;
removePartFromZooKeeper(part_name, ops, stat.numChildren > 0);
zookeeper->multi(ops);
}
void StorageReplicatedMergeTree::removePartAndEnqueueFetch(const String & part_name)
{
auto zookeeper = getZooKeeper();
/// We don't know exactly what happened to broken part
/// and we are going to remove all covered log entries.
/// It's quite dangerous, so clone covered parts to detached.
auto broken_part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
auto partition_range = getDataPartsVectorInPartition(MergeTreeDataPartState::Active, broken_part_info.partition_id);
for (const auto & part : partition_range)
{
if (!broken_part_info.contains(part->info))
continue;
/// Broken part itself ether already moved to detached or does not exist.
assert(broken_part_info != part->info);
part->makeCloneInDetached("covered-by-broken", getInMemoryMetadataPtr());
}
/// It's possible that queue contains entries covered by part_name.
/// For example, we had GET_PART all_1_42_5 and MUTATE_PART all_1_42_5_63,
/// then all_1_42_5_63 was executed by fetching, but part was written to disk incorrectly.
/// In this case we have to remove it as broken and create GET_PART all_1_42_5_63 to fetch it again,
/// but GET_PART all_1_42_5 may be still in the queue.
/// We should remove all covered entries before creating GET_PART entry, because:
/// 1. In the situation described above, we do not know how to merge/mutate all_1_42_5_63 from all_1_42_5,
/// so GET_PART all_1_42_5 (and all source parts) is useless. The only thing we can do is to fetch all_1_42_5_63.
/// 2. If all_1_42_5_63 is lost, then replication may stuck waiting for all_1_42_5_63 to appear,
/// because we may have some covered parts (more precisely, parts with the same min and max blocks)
queue.removePartProducingOpsInRange(zookeeper, broken_part_info, {});
String part_path = fs::path(replica_path) / "parts" / part_name;
Coordination::Requests ops;
time_t part_create_time = 0;
Coordination::Stat stat;
if (zookeeper->exists(part_path, &stat))
{
/// Update version of /is_lost node to avoid race condition with cloneReplica(...).
/// cloneReplica(...) expects that if some entry was executed, then its new_part_name is added to /parts,
/// but we are going to remove it from /parts and add to queue again.
Coordination::Stat is_lost_stat;
String is_lost_value = zookeeper->get(replica_path + "/is_lost", &is_lost_stat);
assert(is_lost_value == "0");
ops.emplace_back(zkutil::makeSetRequest(replica_path + "/is_lost", is_lost_value, is_lost_stat.version));
part_create_time = stat.ctime / 1000;
removePartFromZooKeeper(part_name, ops, stat.numChildren > 0);
}
LogEntryPtr log_entry = std::make_shared<LogEntry>();
log_entry->type = LogEntry::GET_PART;
log_entry->create_time = part_create_time;
log_entry->source_replica = "";
log_entry->new_part_name = part_name;
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(replica_path) / "queue/queue-", log_entry->toString(),
zkutil::CreateMode::PersistentSequential));
auto results = zookeeper->multi(ops);
String path_created = dynamic_cast<const Coordination::CreateResponse &>(*results.back()).path_created;
log_entry->znode_name = path_created.substr(path_created.find_last_of('/') + 1);
queue.insert(zookeeper, log_entry);
}
void StorageReplicatedMergeTree::startBeingLeader()
{
if (!getSettings()->replicated_can_become_leader)
{
LOG_INFO(log, "Will not enter leader election because replicated_can_become_leader=0");
return;
}
zkutil::checkNoOldLeaders(log, *current_zookeeper, fs::path(zookeeper_path) / "leader_election");
LOG_INFO(log, "Became leader");
is_leader = true;
}
void StorageReplicatedMergeTree::stopBeingLeader()
{
if (!is_leader)
return;
LOG_INFO(log, "Stopped being leader");
is_leader = false;
}
ConnectionTimeouts StorageReplicatedMergeTree::getFetchPartHTTPTimeouts(ContextPtr local_context)
{
auto timeouts = ConnectionTimeouts::getHTTPTimeouts(local_context);
auto settings = getSettings();
if (settings->replicated_fetches_http_connection_timeout.changed)
timeouts.connection_timeout = settings->replicated_fetches_http_connection_timeout;
if (settings->replicated_fetches_http_send_timeout.changed)
timeouts.send_timeout = settings->replicated_fetches_http_send_timeout;
if (settings->replicated_fetches_http_receive_timeout.changed)
timeouts.receive_timeout = settings->replicated_fetches_http_receive_timeout;
return timeouts;
}
bool StorageReplicatedMergeTree::checkReplicaHavePart(const String & replica, const String & part_name)
{
auto zookeeper = getZooKeeper();
return zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "parts" / part_name);
}
String StorageReplicatedMergeTree::findReplicaHavingPart(const String & part_name, bool active)
{
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
/// Select replicas in uniformly random order.
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
LOG_TRACE(log, "Candidate replicas: {}", replicas.size());
for (const String & replica : replicas)
{
/// We aren't interested in ourself.
if (replica == replica_name)
continue;
LOG_TRACE(log, "Candidate replica: {}", replica);
if (checkReplicaHavePart(replica, part_name) &&
(!active || zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active")))
return replica;
/// Obviously, replica could become inactive or even vanish after return from this method.
}
return {};
}
String StorageReplicatedMergeTree::findReplicaHavingCoveringPart(LogEntry & entry, bool active)
{
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
/// Select replicas in uniformly random order.
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
for (const String & replica : replicas)
{
if (replica == replica_name)
continue;
if (active && !zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active"))
continue;
String largest_part_found;
Strings parts = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas" / replica / "parts");
for (const String & part_on_replica : parts)
{
if (part_on_replica == entry.new_part_name
|| MergeTreePartInfo::contains(part_on_replica, entry.new_part_name, format_version))
{
if (largest_part_found.empty()
|| MergeTreePartInfo::contains(part_on_replica, largest_part_found, format_version))
{
largest_part_found = part_on_replica;
}
}
}
if (!largest_part_found.empty())
{
bool the_same_part = largest_part_found == entry.new_part_name;
/// Make a check in case if selected part differs from source part
if (!the_same_part)
{
String reject_reason;
if (!queue.addFuturePartIfNotCoveredByThem(largest_part_found, entry, reject_reason))
{
LOG_INFO(log, "Will not fetch part {} covering {}. {}", largest_part_found, entry.new_part_name, reject_reason);
return {};
}
}
return replica;
}
}
return {};
}
String StorageReplicatedMergeTree::findReplicaHavingCoveringPart(
const String & part_name, bool active, String & found_part_name)
{
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
/// Select replicas in uniformly random order.
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
String largest_part_found;
String largest_replica_found;
for (const String & replica : replicas)
{
if (replica == replica_name)
continue;
if (active && !zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active"))
continue;
Strings parts = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas" / replica / "parts");
for (const String & part_on_replica : parts)
{
if (part_on_replica == part_name
|| MergeTreePartInfo::contains(part_on_replica, part_name, format_version))
{
if (largest_part_found.empty()
|| MergeTreePartInfo::contains(part_on_replica, largest_part_found, format_version))
{
largest_part_found = part_on_replica;
largest_replica_found = replica;
}
}
}
}
found_part_name = largest_part_found;
return largest_replica_found;
}
/** If a quorum is tracked for a part, update information about it in ZK.
*/
void StorageReplicatedMergeTree::updateQuorum(const String & part_name, bool is_parallel)
{
auto zookeeper = getZooKeeper();
/// Information on which replicas a part has been added, if the quorum has not yet been reached.
String quorum_status_path = fs::path(zookeeper_path) / "quorum" / "status";
if (is_parallel)
quorum_status_path = fs::path(zookeeper_path) / "quorum" / "parallel" / part_name;
/// The name of the previous part for which the quorum was reached.
const String quorum_last_part_path = fs::path(zookeeper_path) / "quorum" / "last_part";
String value;
Coordination::Stat stat;
/// If there is no node, then all quorum INSERTs have already reached the quorum, and nothing is needed.
while (zookeeper->tryGet(quorum_status_path, value, &stat))
{
ReplicatedMergeTreeQuorumEntry quorum_entry(value);
if (quorum_entry.part_name != part_name)
{
LOG_TRACE(log, "Quorum {}, already achieved for part {} current part {}",
quorum_status_path, part_name, quorum_entry.part_name);
/// The quorum has already been achieved. Moreover, another INSERT with a quorum has already started.
break;
}
quorum_entry.replicas.insert(replica_name);
if (quorum_entry.replicas.size() >= quorum_entry.required_number_of_replicas)
{
/// The quorum is reached. Delete the node, and update information about the last part that was successfully written with quorum.
LOG_TRACE(log, "Got {} replicas confirmed quorum {}, going to remove node",
quorum_entry.replicas.size(), quorum_status_path);
Coordination::Requests ops;
Coordination::Responses responses;
if (!is_parallel)
{
Coordination::Stat added_parts_stat;
String old_added_parts = zookeeper->get(quorum_last_part_path, &added_parts_stat);
ReplicatedMergeTreeQuorumAddedParts parts_with_quorum(format_version);
if (!old_added_parts.empty())
parts_with_quorum.fromString(old_added_parts);
auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
/// We store one last part which reached quorum for each partition.
parts_with_quorum.added_parts[part_info.partition_id] = part_name;
String new_added_parts = parts_with_quorum.toString();
ops.emplace_back(zkutil::makeRemoveRequest(quorum_status_path, stat.version));
ops.emplace_back(zkutil::makeSetRequest(quorum_last_part_path, new_added_parts, added_parts_stat.version));
}
else
ops.emplace_back(zkutil::makeRemoveRequest(quorum_status_path, stat.version));
auto code = zookeeper->tryMulti(ops, responses);
if (code == Coordination::Error::ZOK)
{
break;
}
else if (code == Coordination::Error::ZNONODE)
{
/// The quorum has already been achieved.
break;
}
else if (code == Coordination::Error::ZBADVERSION)
{
/// Node was updated meanwhile. We must re-read it and repeat all the actions.
continue;
}
else
throw Coordination::Exception(code, quorum_status_path);
}
else
{
LOG_TRACE(log, "Quorum {} still not satisfied (have only {} replicas), updating node",
quorum_status_path, quorum_entry.replicas.size());
/// We update the node, registering there one more replica.
auto code = zookeeper->trySet(quorum_status_path, quorum_entry.toString(), stat.version);
if (code == Coordination::Error::ZOK)
{
break;
}
else if (code == Coordination::Error::ZNONODE)
{
/// The quorum has already been achieved.
break;
}
else if (code == Coordination::Error::ZBADVERSION)
{
/// Node was updated meanwhile. We must re-read it and repeat all the actions.
continue;
}
else
throw Coordination::Exception(code, quorum_status_path);
}
}
}
void StorageReplicatedMergeTree::cleanLastPartNode(const String & partition_id)
{
auto zookeeper = getZooKeeper();
/// The name of the previous part for which the quorum was reached.
const String quorum_last_part_path = fs::path(zookeeper_path) / "quorum" / "last_part";
/// Delete information from "last_part" node.
while (true)
{
Coordination::Stat added_parts_stat;
String old_added_parts = zookeeper->get(quorum_last_part_path, &added_parts_stat);
ReplicatedMergeTreeQuorumAddedParts parts_with_quorum(format_version);
if (!old_added_parts.empty())
parts_with_quorum.fromString(old_added_parts);
/// Delete information about particular partition.
if (!parts_with_quorum.added_parts.count(partition_id))
{
/// There is no information about interested part.
break;
}
parts_with_quorum.added_parts.erase(partition_id);
String new_added_parts = parts_with_quorum.toString();
auto code = zookeeper->trySet(quorum_last_part_path, new_added_parts, added_parts_stat.version);
if (code == Coordination::Error::ZOK)
{
break;
}
else if (code == Coordination::Error::ZNONODE)
{
/// Node is deleted. It is impossible, but it is Ok.
break;
}
else if (code == Coordination::Error::ZBADVERSION)
{
/// Node was updated meanwhile. We must re-read it and repeat all the actions.
continue;
}
else
throw Coordination::Exception(code, quorum_last_part_path);
}
}
bool StorageReplicatedMergeTree::partIsInsertingWithParallelQuorum(const MergeTreePartInfo & part_info) const
{
auto zookeeper = getZooKeeper();
return zookeeper->exists(fs::path(zookeeper_path) / "quorum" / "parallel" / part_info.getPartName());
}
bool StorageReplicatedMergeTree::partIsLastQuorumPart(const MergeTreePartInfo & part_info) const
{
auto zookeeper = getZooKeeper();
const String parts_with_quorum_path = fs::path(zookeeper_path) / "quorum" / "last_part";
String parts_with_quorum_str = zookeeper->get(parts_with_quorum_path);
if (parts_with_quorum_str.empty())
return false;
ReplicatedMergeTreeQuorumAddedParts parts_with_quorum(format_version);
parts_with_quorum.fromString(parts_with_quorum_str);
auto partition_it = parts_with_quorum.added_parts.find(part_info.partition_id);
if (partition_it == parts_with_quorum.added_parts.end())
return false;
return partition_it->second == part_info.getPartName();
}
bool StorageReplicatedMergeTree::fetchPart(const String & part_name, const StorageMetadataPtr & metadata_snapshot,
const String & source_replica_path, bool to_detached, size_t quorum, zkutil::ZooKeeper::Ptr zookeeper_)
{
auto zookeeper = zookeeper_ ? zookeeper_ : getZooKeeper();
const auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
if (!to_detached)
{
if (auto part = getPartIfExists(part_info, {IMergeTreeDataPart::State::Outdated, IMergeTreeDataPart::State::Deleting}))
{
LOG_DEBUG(log, "Part {} should be deleted after previous attempt before fetch", part->name);
/// Force immediate parts cleanup to delete the part that was left from the previous fetch attempt.
cleanup_thread.wakeup();
return false;
}
}
{
std::lock_guard lock(currently_fetching_parts_mutex);
if (!currently_fetching_parts.insert(part_name).second)
{
LOG_DEBUG(log, "Part {} is already fetching right now", part_name);
return false;
}
}
SCOPE_EXIT_MEMORY
({
std::lock_guard lock(currently_fetching_parts_mutex);
currently_fetching_parts.erase(part_name);
});
LOG_DEBUG(log, "Fetching part {} from {}", part_name, source_replica_path);
TableLockHolder table_lock_holder;
if (!to_detached)
table_lock_holder = lockForShare(RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
/// Logging
Stopwatch stopwatch;
MutableDataPartPtr part;
DataPartsVector replaced_parts;
auto write_part_log = [&] (const ExecutionStatus & execution_status)
{
writePartLog(
PartLogElement::DOWNLOAD_PART, execution_status, stopwatch.elapsed(),
part_name, part, replaced_parts, nullptr);
};
DataPartPtr part_to_clone;
{
/// If the desired part is a result of a part mutation, try to find the source part and compare
/// its checksums to the checksums of the desired part. If they match, we can just clone the local part.
/// If we have the source part, its part_info will contain covered_part_info.
auto covered_part_info = part_info;
covered_part_info.mutation = 0;
auto source_part = getActiveContainingPart(covered_part_info);
if (source_part)
{
auto source_part_header = ReplicatedMergeTreePartHeader::fromColumnsAndChecksums(
source_part->getColumns(), source_part->checksums);
String part_path = fs::path(source_replica_path) / "parts" / part_name;
String part_znode = zookeeper->get(part_path);
std::optional<ReplicatedMergeTreePartHeader> desired_part_header;
if (!part_znode.empty())
{
desired_part_header = ReplicatedMergeTreePartHeader::fromString(part_znode);
}
else
{
String columns_str;
String checksums_str;
if (zookeeper->tryGet(fs::path(part_path) / "columns", columns_str) &&
zookeeper->tryGet(fs::path(part_path) / "checksums", checksums_str))
{
desired_part_header = ReplicatedMergeTreePartHeader::fromColumnsAndChecksumsZNodes(columns_str, checksums_str);
}
else
{
LOG_INFO(log, "Not checking checksums of part {} with replica {} because part was removed from ZooKeeper", part_name, source_replica_path);
}
}
/// Checking both checksums and columns hash. For example we can have empty part
/// with same checksums but different columns. And we attaching it exception will
/// be thrown.
if (desired_part_header
&& source_part_header.getColumnsHash() == desired_part_header->getColumnsHash()
&& source_part_header.getChecksums() == desired_part_header->getChecksums())
{
LOG_TRACE(log, "Found local part {} with the same checksums and columns hash as {}", source_part->name, part_name);
part_to_clone = source_part;
}
}
}
ReplicatedMergeTreeAddress address;
ConnectionTimeouts timeouts;
String interserver_scheme;
InterserverCredentialsPtr credentials;
std::optional<CurrentlySubmergingEmergingTagger> tagger_ptr;
std::function<MutableDataPartPtr()> get_part;
if (part_to_clone)
{
get_part = [&, part_to_clone]()
{
return cloneAndLoadDataPartOnSameDisk(part_to_clone, "tmp_clone_", part_info, metadata_snapshot);
};
}
else
{
address.fromString(zookeeper->get(fs::path(source_replica_path) / "host"));
timeouts = getFetchPartHTTPTimeouts(getContext());
credentials = getContext()->getInterserverCredentials();
interserver_scheme = getContext()->getInterserverScheme();
get_part = [&, address, timeouts, credentials, interserver_scheme]()
{
if (interserver_scheme != address.scheme)
throw Exception("Interserver schemes are different: '" + interserver_scheme
+ "' != '" + address.scheme + "', can't fetch part from " + address.host,
ErrorCodes::INTERSERVER_SCHEME_DOESNT_MATCH);
return fetcher.fetchPart(
metadata_snapshot,
getContext(),
part_name,
source_replica_path,
address.host,
address.replication_port,
timeouts,
credentials->getUser(),
credentials->getPassword(),
interserver_scheme,
replicated_fetches_throttler,
to_detached,
"",
&tagger_ptr,
true);
};
}
try
{
part = get_part();
if (!to_detached)
{
Transaction transaction(*this);
renameTempPartAndReplace(part, nullptr, &transaction);
replaced_parts = checkPartChecksumsAndCommit(transaction, part);
/** If a quorum is tracked for this part, you must update it.
* If you do not have time, in case of losing the session, when you restart the server - see the `ReplicatedMergeTreeRestartingThread::updateQuorumIfWeHavePart` method.
*/
if (quorum)
{
/// Check if this quorum insert is parallel or not
if (zookeeper->exists(fs::path(zookeeper_path) / "quorum" / "parallel" / part_name))
updateQuorum(part_name, true);
else if (zookeeper->exists(fs::path(zookeeper_path) / "quorum" / "status"))
updateQuorum(part_name, false);
}
/// merged parts that are still inserted with quorum. if it only contains one block, it hasn't been merged before
if (part_info.level != 0 || part_info.mutation != 0)
{
Strings quorum_parts = zookeeper->getChildren(fs::path(zookeeper_path) / "quorum" / "parallel");
for (const String & quorum_part : quorum_parts)
{
auto quorum_part_info = MergeTreePartInfo::fromPartName(quorum_part, format_version);
if (part_info.contains(quorum_part_info))
updateQuorum(quorum_part, true);
}
}
merge_selecting_task->schedule();
for (const auto & replaced_part : replaced_parts)
{
LOG_DEBUG(log, "Part {} is rendered obsolete by fetching part {}", replaced_part->name, part_name);
ProfileEvents::increment(ProfileEvents::ObsoleteReplicatedParts);
}
write_part_log({});
}
else
{
// The fetched part is valuable and should not be cleaned like a temp part.
part->is_temp = false;
part->renameTo(fs::path("detached") / part_name, true);
}
}
catch (const Exception & e)
{
/// The same part is being written right now (but probably it's not committed yet).
/// We will check the need for fetch later.
if (e.code() == ErrorCodes::DIRECTORY_ALREADY_EXISTS)
return false;
throw;
}
catch (...)
{
if (!to_detached)
write_part_log(ExecutionStatus::fromCurrentException());
throw;
}
ProfileEvents::increment(ProfileEvents::ReplicatedPartFetches);
if (part_to_clone)
LOG_DEBUG(log, "Cloned part {} from {}{}", part_name, part_to_clone->name, to_detached ? " (to 'detached' directory)" : "");
else
LOG_DEBUG(log, "Fetched part {} from {}{}", part_name, source_replica_path, to_detached ? " (to 'detached' directory)" : "");
return true;
}
bool StorageReplicatedMergeTree::fetchExistsPart(const String & part_name, const StorageMetadataPtr & metadata_snapshot,
const String & source_replica_path, DiskPtr replaced_disk, String replaced_part_path)
{
auto zookeeper = getZooKeeper();
const auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
if (auto part = getPartIfExists(part_info, {IMergeTreeDataPart::State::Outdated, IMergeTreeDataPart::State::Deleting}))
{
LOG_DEBUG(log, "Part {} should be deleted after previous attempt before fetch", part->name);
/// Force immediate parts cleanup to delete the part that was left from the previous fetch attempt.
cleanup_thread.wakeup();
return false;
}
{
std::lock_guard lock(currently_fetching_parts_mutex);
if (!currently_fetching_parts.insert(part_name).second)
{
LOG_DEBUG(log, "Part {} is already fetching right now", part_name);
return false;
}
}
SCOPE_EXIT_MEMORY
({
std::lock_guard lock(currently_fetching_parts_mutex);
currently_fetching_parts.erase(part_name);
});
LOG_DEBUG(log, "Fetching part {} from {}", part_name, source_replica_path);
TableLockHolder table_lock_holder = lockForShare(RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
/// Logging
Stopwatch stopwatch;
MutableDataPartPtr part;
DataPartsVector replaced_parts;
auto write_part_log = [&] (const ExecutionStatus & execution_status)
{
writePartLog(
PartLogElement::DOWNLOAD_PART, execution_status, stopwatch.elapsed(),
part_name, part, replaced_parts, nullptr);
};
std::function<MutableDataPartPtr()> get_part;
ReplicatedMergeTreeAddress address(zookeeper->get(fs::path(source_replica_path) / "host"));
auto timeouts = ConnectionTimeouts::getHTTPTimeouts(getContext());
auto credentials = getContext()->getInterserverCredentials();
String interserver_scheme = getContext()->getInterserverScheme();
get_part = [&, address, timeouts, interserver_scheme, credentials]()
{
if (interserver_scheme != address.scheme)
throw Exception("Interserver schemes are different: '" + interserver_scheme
+ "' != '" + address.scheme + "', can't fetch part from " + address.host,
ErrorCodes::INTERSERVER_SCHEME_DOESNT_MATCH);
return fetcher.fetchPart(
metadata_snapshot, getContext(), part_name, source_replica_path,
address.host, address.replication_port,
timeouts, credentials->getUser(), credentials->getPassword(),
interserver_scheme, replicated_fetches_throttler, false, "", nullptr, true,
replaced_disk);
};
try
{
part = get_part();
if (part->volume->getDisk()->getName() != replaced_disk->getName())
throw Exception("Part " + part->name + " fetched on wrong disk " + part->volume->getDisk()->getName(), ErrorCodes::LOGICAL_ERROR);
replaced_disk->removeFileIfExists(replaced_part_path);
replaced_disk->moveDirectory(part->getFullRelativePath(), replaced_part_path);
}
catch (const Exception & e)
{
/// The same part is being written right now (but probably it's not committed yet).
/// We will check the need for fetch later.
if (e.code() == ErrorCodes::DIRECTORY_ALREADY_EXISTS)
return false;
throw;
}
catch (...)
{
write_part_log(ExecutionStatus::fromCurrentException());
throw;
}
ProfileEvents::increment(ProfileEvents::ReplicatedPartFetches);
LOG_DEBUG(log, "Fetched part {} from {}", part_name, source_replica_path);
return true;
}
void StorageReplicatedMergeTree::startup()
{
/// Do not start replication if ZooKeeper is not configured or there is no metadata in zookeeper
if (!has_metadata_in_zookeeper.has_value() || !*has_metadata_in_zookeeper)
return;
try
{
InterserverIOEndpointPtr data_parts_exchange_ptr = std::make_shared<DataPartsExchange::Service>(*this);
[[maybe_unused]] auto prev_ptr = std::atomic_exchange(&data_parts_exchange_endpoint, data_parts_exchange_ptr);
assert(prev_ptr == nullptr);
getContext()->getInterserverIOHandler().addEndpoint(data_parts_exchange_ptr->getId(replica_path), data_parts_exchange_ptr);
startBeingLeader();
/// In this thread replica will be activated.
restarting_thread.start();
/// Wait while restarting_thread finishing initialization.
/// NOTE It does not mean that replication is actually started after receiving this event.
/// It only means that an attempt to startup replication was made.
/// Table may be still in readonly mode if this attempt failed for any reason.
startup_event.wait();
startBackgroundMovesIfNeeded();
part_moves_between_shards_orchestrator.start();
}
catch (...)
{
/// Exception safety: failed "startup" does not require a call to "shutdown" from the caller.
/// And it should be able to safely destroy table after exception in "startup" method.
/// It means that failed "startup" must not create any background tasks that we will have to wait.
try
{
shutdown();
}
catch (...)
{
std::terminate();
}
/// Note: after failed "startup", the table will be in a state that only allows to destroy the object.
throw;
}
}
void StorageReplicatedMergeTree::flush()
{
if (flush_called.exchange(true))
return;
flushAllInMemoryPartsIfNeeded();
}
void StorageReplicatedMergeTree::shutdown()
{
if (shutdown_called.exchange(true))
return;
/// Cancel fetches, merges and mutations to force the queue_task to finish ASAP.
fetcher.blocker.cancelForever();
merger_mutator.merges_blocker.cancelForever();
parts_mover.moves_blocker.cancelForever();
stopBeingLeader();
restarting_thread.shutdown();
background_operations_assignee.finish();
part_moves_between_shards_orchestrator.shutdown();
{
auto lock = queue.lockQueue();
/// Cancel logs pulling after background task were cancelled. It's still
/// required because we can trigger pullLogsToQueue during manual OPTIMIZE,
/// MUTATE, etc. query.
queue.pull_log_blocker.cancelForever();
}
background_moves_assignee.finish();
auto data_parts_exchange_ptr = std::atomic_exchange(&data_parts_exchange_endpoint, InterserverIOEndpointPtr{});
if (data_parts_exchange_ptr)
{
getContext()->getInterserverIOHandler().removeEndpointIfExists(data_parts_exchange_ptr->getId(replica_path));
/// Ask all parts exchange handlers to finish asap. New ones will fail to start
data_parts_exchange_ptr->blocker.cancelForever();
/// Wait for all of them
std::unique_lock lock(data_parts_exchange_ptr->rwlock);
}
}
StorageReplicatedMergeTree::~StorageReplicatedMergeTree()
{
try
{
shutdown();
}
catch (...)
{
tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock StorageReplicatedMergeTree::getMaxAddedBlocks() const
{
ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock max_added_blocks;
for (const auto & data_part : getDataParts())
{
max_added_blocks[data_part->info.partition_id]
= std::max(max_added_blocks[data_part->info.partition_id], data_part->info.max_block);
}
auto zookeeper = getZooKeeper();
const String quorum_status_path = fs::path(zookeeper_path) / "quorum" / "status";
String value;
Coordination::Stat stat;
if (zookeeper->tryGet(quorum_status_path, value, &stat))
{
ReplicatedMergeTreeQuorumEntry quorum_entry;
quorum_entry.fromString(value);
auto part_info = MergeTreePartInfo::fromPartName(quorum_entry.part_name, format_version);
max_added_blocks[part_info.partition_id] = part_info.max_block - 1;
}
String added_parts_str;
if (zookeeper->tryGet(fs::path(zookeeper_path) / "quorum" / "last_part", added_parts_str))
{
if (!added_parts_str.empty())
{
ReplicatedMergeTreeQuorumAddedParts part_with_quorum(format_version);
part_with_quorum.fromString(added_parts_str);
auto added_parts = part_with_quorum.added_parts;
for (const auto & added_part : added_parts)
if (!getActiveContainingPart(added_part.second))
throw Exception(
"Replica doesn't have part " + added_part.second
+ " which was successfully written to quorum of other replicas."
" Send query to another replica or disable 'select_sequential_consistency' setting.",
ErrorCodes::REPLICA_IS_NOT_IN_QUORUM);
for (const auto & max_block : part_with_quorum.getMaxInsertedBlocks())
max_added_blocks[max_block.first] = max_block.second;
}
}
return max_added_blocks;
}
void StorageReplicatedMergeTree::read(
QueryPlan & query_plan,
const Names & column_names,
const StorageSnapshotPtr & storage_snapshot,
SelectQueryInfo & query_info,
ContextPtr local_context,
QueryProcessingStage::Enum processed_stage,
const size_t max_block_size,
const unsigned num_streams)
{
/// If true, then we will ask initiator if we can read chosen ranges
const bool enable_parallel_reading = local_context->getClientInfo().collaborate_with_initiator;
/** The `select_sequential_consistency` setting has two meanings:
* 1. To throw an exception if on a replica there are not all parts which have been written down on quorum of remaining replicas.
* 2. Do not read parts that have not yet been written to the quorum of the replicas.
* For this you have to synchronously go to ZooKeeper.
*/
if (local_context->getSettingsRef().select_sequential_consistency)
{
auto max_added_blocks = std::make_shared<ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock>(getMaxAddedBlocks());
if (auto plan = reader.read(
column_names, storage_snapshot, query_info, local_context,
max_block_size, num_streams, processed_stage, std::move(max_added_blocks), enable_parallel_reading))
query_plan = std::move(*plan);
return;
}
if (auto plan = reader.read(
column_names, storage_snapshot, query_info, local_context,
max_block_size, num_streams, processed_stage, nullptr, enable_parallel_reading))
{
query_plan = std::move(*plan);
}
}
Pipe StorageReplicatedMergeTree::read(
const Names & column_names,
const StorageSnapshotPtr & storage_snapshot,
SelectQueryInfo & query_info,
ContextPtr local_context,
QueryProcessingStage::Enum processed_stage,
const size_t max_block_size,
const unsigned num_streams)
{
QueryPlan plan;
read(plan, column_names, storage_snapshot, query_info, local_context, processed_stage, max_block_size, num_streams);
return plan.convertToPipe(
QueryPlanOptimizationSettings::fromContext(local_context),
BuildQueryPipelineSettings::fromContext(local_context));
}
template <class Func>
void StorageReplicatedMergeTree::foreachActiveParts(Func && func, bool select_sequential_consistency) const
{
std::optional<ReplicatedMergeTreeQuorumAddedParts::PartitionIdToMaxBlock> max_added_blocks = {};
/**
* Synchronously go to ZooKeeper when select_sequential_consistency enabled
*/
if (select_sequential_consistency)
max_added_blocks = getMaxAddedBlocks();
auto lock = lockParts();
for (const auto & part : getDataPartsStateRange(DataPartState::Active))
{
if (part->isEmpty())
continue;
if (max_added_blocks)
{
auto blocks_iterator = max_added_blocks->find(part->info.partition_id);
if (blocks_iterator == max_added_blocks->end() || part->info.max_block > blocks_iterator->second)
continue;
}
func(part);
}
}
std::optional<UInt64> StorageReplicatedMergeTree::totalRows(const Settings & settings) const
{
UInt64 res = 0;
foreachActiveParts([&res](auto & part) { res += part->rows_count; }, settings.select_sequential_consistency);
return res;
}
std::optional<UInt64> StorageReplicatedMergeTree::totalRowsByPartitionPredicate(const SelectQueryInfo & query_info, ContextPtr local_context) const
{
DataPartsVector parts;
foreachActiveParts([&](auto & part) { parts.push_back(part); }, local_context->getSettingsRef().select_sequential_consistency);
return totalRowsByPartitionPredicateImpl(query_info, local_context, parts);
}
std::optional<UInt64> StorageReplicatedMergeTree::totalBytes(const Settings & settings) const
{
UInt64 res = 0;
foreachActiveParts([&res](auto & part) { res += part->getBytesOnDisk(); }, settings.select_sequential_consistency);
return res;
}
void StorageReplicatedMergeTree::assertNotReadonly() const
{
if (is_readonly)
throw Exception(ErrorCodes::TABLE_IS_READ_ONLY, "Table is in readonly mode (zookeeper path: {})", zookeeper_path);
}
SinkToStoragePtr StorageReplicatedMergeTree::write(const ASTPtr & /*query*/, const StorageMetadataPtr & metadata_snapshot, ContextPtr local_context)
{
const auto storage_settings_ptr = getSettings();
assertNotReadonly();
const Settings & query_settings = local_context->getSettingsRef();
bool deduplicate = storage_settings_ptr->replicated_deduplication_window != 0 && query_settings.insert_deduplicate;
// TODO: should we also somehow pass list of columns to deduplicate on to the ReplicatedMergeTreeBlockOutputStream ?
return std::make_shared<ReplicatedMergeTreeSink>(
*this, metadata_snapshot, query_settings.insert_quorum,
query_settings.insert_quorum_timeout.totalMilliseconds(),
query_settings.max_partitions_per_insert_block,
query_settings.insert_quorum_parallel,
deduplicate,
local_context);
}
bool StorageReplicatedMergeTree::optimize(
const ASTPtr &,
const StorageMetadataPtr &,
const ASTPtr & partition,
bool final,
bool deduplicate,
const Names & deduplicate_by_columns,
ContextPtr query_context)
{
/// NOTE: exclusive lock cannot be used here, since this may lead to deadlock (see comments below),
/// but it should be safe to use non-exclusive to avoid dropping parts that may be required for processing queue.
auto table_lock = lockForShare(query_context->getCurrentQueryId(), query_context->getSettingsRef().lock_acquire_timeout);
assertNotReadonly();
if (!is_leader)
throw Exception("OPTIMIZE cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
auto handle_noop = [&] (const String & message)
{
if (query_context->getSettingsRef().optimize_throw_if_noop)
throw Exception(message, ErrorCodes::CANNOT_ASSIGN_OPTIMIZE);
return false;
};
auto zookeeper = getZooKeeperAndAssertNotReadonly();
const auto storage_settings_ptr = getSettings();
auto metadata_snapshot = getInMemoryMetadataPtr();
std::vector<ReplicatedMergeTreeLogEntryData> merge_entries;
auto try_assign_merge = [&](const String & partition_id) -> bool
{
constexpr size_t max_retries = 10;
size_t try_no = 0;
for (; try_no < max_retries; ++try_no)
{
/// We must select parts for merge under merge_selecting_mutex because other threads
/// (merge_selecting_thread or OPTIMIZE queries) could assign new merges.
std::lock_guard merge_selecting_lock(merge_selecting_mutex);
ReplicatedMergeTreeMergePredicate can_merge = queue.getMergePredicate(zookeeper);
auto future_merged_part = std::make_shared<FutureMergedMutatedPart>();
if (storage_settings.get()->assign_part_uuids)
future_merged_part->uuid = UUIDHelpers::generateV4();
constexpr const char * unknown_disable_reason = "unknown reason";
String disable_reason = unknown_disable_reason;
SelectPartsDecision select_decision = SelectPartsDecision::CANNOT_SELECT;
if (partition_id.empty())
{
select_decision = merger_mutator.selectPartsToMerge(
future_merged_part, /* aggressive */ true, storage_settings_ptr->max_bytes_to_merge_at_max_space_in_pool,
can_merge, /* merge_with_ttl_allowed */ false, &disable_reason);
}
else
{
select_decision = merger_mutator.selectAllPartsToMergeWithinPartition(
future_merged_part, can_merge, partition_id, final, metadata_snapshot,
&disable_reason, query_context->getSettingsRef().optimize_skip_merged_partitions);
}
/// If there is nothing to merge then we treat this merge as successful (needed for optimize final optimization)
if (select_decision == SelectPartsDecision::NOTHING_TO_MERGE)
return false;
if (select_decision != SelectPartsDecision::SELECTED)
{
constexpr const char * message_fmt = "Cannot select parts for optimization: {}";
assert(disable_reason != unknown_disable_reason);
if (!partition_id.empty())
disable_reason += fmt::format(" (in partition {})", partition_id);
String message = fmt::format(message_fmt, disable_reason);
LOG_INFO(log, fmt::runtime(message));
return handle_noop(message);
}
ReplicatedMergeTreeLogEntryData merge_entry;
CreateMergeEntryResult create_result = createLogEntryToMergeParts(
zookeeper, future_merged_part->parts,
future_merged_part->name, future_merged_part->uuid, future_merged_part->type,
deduplicate, deduplicate_by_columns,
&merge_entry, can_merge.getVersion(), future_merged_part->merge_type);
if (create_result == CreateMergeEntryResult::MissingPart)
{
String message = "Can't create merge queue node in ZooKeeper, because some parts are missing";
LOG_TRACE(log, fmt::runtime(message));
return handle_noop(message);
}
if (create_result == CreateMergeEntryResult::LogUpdated)
continue;
merge_entries.push_back(std::move(merge_entry));
return true;
}
assert(try_no == max_retries);
String message = fmt::format("Can't create merge queue node in ZooKeeper, because log was updated in every of {} tries", try_no);
LOG_TRACE(log, fmt::runtime(message));
return handle_noop(message);
};
bool assigned = false;
if (!partition && final)
{
DataPartsVector data_parts = getDataPartsVector();
std::unordered_set<String> partition_ids;
for (const DataPartPtr & part : data_parts)
partition_ids.emplace(part->info.partition_id);
for (const String & partition_id : partition_ids)
{
assigned = try_assign_merge(partition_id);
if (!assigned)
break;
}
}
else
{
String partition_id;
if (partition)
partition_id = getPartitionIDFromQuery(partition, query_context);
assigned = try_assign_merge(partition_id);
}
table_lock.reset();
for (auto & merge_entry : merge_entries)
waitForLogEntryToBeProcessedIfNecessary(merge_entry, query_context);
return assigned;
}
bool StorageReplicatedMergeTree::executeMetadataAlter(const StorageReplicatedMergeTree::LogEntry & entry)
{
if (entry.alter_version < metadata_version)
{
/// TODO Can we replace it with LOGICAL_ERROR?
/// As for now, it may rerely happen due to reordering of ALTER_METADATA entries in the queue of
/// non-initial replica and also may happen after stale replica recovery.
LOG_WARNING(log, "Attempt to update metadata of version {} "
"to older version {} when processing log entry {}: {}",
metadata_version, entry.alter_version, entry.znode_name, entry.toString());
return true;
}
auto zookeeper = getZooKeeper();
auto columns_from_entry = ColumnsDescription::parse(entry.columns_str);
auto metadata_from_entry = ReplicatedMergeTreeTableMetadata::parse(entry.metadata_str);
MergeTreeData::DataParts parts;
/// If metadata nodes have changed, we will update table structure locally.
Coordination::Requests requests;
requests.emplace_back(zkutil::makeSetRequest(fs::path(replica_path) / "columns", entry.columns_str, -1));
requests.emplace_back(zkutil::makeSetRequest(fs::path(replica_path) / "metadata", entry.metadata_str, -1));
zookeeper->multi(requests);
{
auto table_lock_holder = lockForShare(RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
auto alter_lock_holder = lockForAlter(getSettings()->lock_acquire_timeout_for_background_operations);
LOG_INFO(log, "Metadata changed in ZooKeeper. Applying changes locally.");
auto metadata_diff = ReplicatedMergeTreeTableMetadata(*this, getInMemoryMetadataPtr()).checkAndFindDiff(metadata_from_entry, getInMemoryMetadataPtr()->getColumns(), getContext());
setTableStructure(std::move(columns_from_entry), metadata_diff);
metadata_version = entry.alter_version;
LOG_INFO(log, "Applied changes to the metadata of the table. Current metadata version: {}", metadata_version);
}
/// This transaction may not happen, but it's OK, because on the next retry we will eventually create/update this node
zookeeper->createOrUpdate(fs::path(replica_path) / "metadata_version", std::to_string(metadata_version), zkutil::CreateMode::Persistent);
return true;
}
PartitionBlockNumbersHolder StorageReplicatedMergeTree::allocateBlockNumbersInAffectedPartitions(
const MutationCommands & commands, ContextPtr query_context, const zkutil::ZooKeeperPtr & zookeeper) const
{
const std::set<String> mutation_affected_partition_ids = getPartitionIdsAffectedByCommands(commands, query_context);
if (mutation_affected_partition_ids.size() == 1)
{
const auto & affected_partition_id = *mutation_affected_partition_ids.cbegin();
auto block_number_holder = allocateBlockNumber(affected_partition_id, zookeeper);
if (!block_number_holder.has_value())
return {};
auto block_number = block_number_holder->getNumber(); /// Avoid possible UB due to std::move
return {{{affected_partition_id, block_number}}, std::move(block_number_holder)};
}
else
{
/// TODO: Implement optimal block number aqcuisition algorithm in multiple (but not all) partitions
EphemeralLocksInAllPartitions lock_holder(
fs::path(zookeeper_path) / "block_numbers", "block-", fs::path(zookeeper_path) / "temp", *zookeeper);
PartitionBlockNumbersHolder::BlockNumbersType block_numbers;
for (const auto & lock : lock_holder.getLocks())
{
if (mutation_affected_partition_ids.empty() || mutation_affected_partition_ids.count(lock.partition_id))
block_numbers[lock.partition_id] = lock.number;
}
return {std::move(block_numbers), std::move(lock_holder)};
}
}
void StorageReplicatedMergeTree::alter(
const AlterCommands & commands, ContextPtr query_context, AlterLockHolder & table_lock_holder)
{
assertNotReadonly();
auto table_id = getStorageID();
if (commands.isSettingsAlter())
{
/// We don't replicate storage_settings_ptr ALTER. It's local operation.
/// Also we don't upgrade alter lock to table structure lock.
StorageInMemoryMetadata future_metadata = getInMemoryMetadata();
commands.apply(future_metadata, query_context);
merge_strategy_picker.refreshState();
changeSettings(future_metadata.settings_changes, table_lock_holder);
DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(query_context, table_id, future_metadata);
return;
}
auto ast_to_str = [](ASTPtr query) -> String
{
if (!query)
return "";
return queryToString(query);
};
const auto zookeeper = getZooKeeperAndAssertNotReadonly();
std::optional<ReplicatedMergeTreeLogEntryData> alter_entry;
std::optional<String> mutation_znode;
while (true)
{
/// Clear nodes from previous iteration
alter_entry.emplace();
mutation_znode.reset();
auto current_metadata = getInMemoryMetadataPtr();
StorageInMemoryMetadata future_metadata = *current_metadata;
commands.apply(future_metadata, query_context);
ReplicatedMergeTreeTableMetadata future_metadata_in_zk(*this, current_metadata);
if (ast_to_str(future_metadata.sorting_key.definition_ast) != ast_to_str(current_metadata->sorting_key.definition_ast))
{
/// We serialize definition_ast as list, because code which apply ALTER (setTableStructure) expect serialized non empty expression
/// list here and we cannot change this representation for compatibility. Also we have preparsed AST `sorting_key.expression_list_ast`
/// in KeyDescription, but it contain version column for VersionedCollapsingMergeTree, which shouldn't be defined as a part of key definition AST.
/// So the best compatible way is just to convert definition_ast to list and serialize it. In all other places key.expression_list_ast should be used.
future_metadata_in_zk.sorting_key = serializeAST(*extractKeyExpressionList(future_metadata.sorting_key.definition_ast));
}
if (ast_to_str(future_metadata.sampling_key.definition_ast) != ast_to_str(current_metadata->sampling_key.definition_ast))
future_metadata_in_zk.sampling_expression = serializeAST(*extractKeyExpressionList(future_metadata.sampling_key.definition_ast));
if (ast_to_str(future_metadata.partition_key.definition_ast) != ast_to_str(current_metadata->partition_key.definition_ast))
future_metadata_in_zk.partition_key = serializeAST(*extractKeyExpressionList(future_metadata.partition_key.definition_ast));
if (ast_to_str(future_metadata.table_ttl.definition_ast) != ast_to_str(current_metadata->table_ttl.definition_ast))
{
if (future_metadata.table_ttl.definition_ast)
future_metadata_in_zk.ttl_table = serializeAST(*future_metadata.table_ttl.definition_ast);
else /// TTL was removed
future_metadata_in_zk.ttl_table = "";
}
String new_indices_str = future_metadata.secondary_indices.toString();
if (new_indices_str != current_metadata->secondary_indices.toString())
future_metadata_in_zk.skip_indices = new_indices_str;
String new_projections_str = future_metadata.projections.toString();
if (new_projections_str != current_metadata->projections.toString())
future_metadata_in_zk.projections = new_projections_str;
String new_constraints_str = future_metadata.constraints.toString();
if (new_constraints_str != current_metadata->constraints.toString())
future_metadata_in_zk.constraints = new_constraints_str;
Coordination::Requests ops;
size_t alter_path_idx = std::numeric_limits<size_t>::max();
size_t mutation_path_idx = std::numeric_limits<size_t>::max();
String new_metadata_str = future_metadata_in_zk.toString();
ops.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "metadata", new_metadata_str, metadata_version));
String new_columns_str = future_metadata.columns.toString();
ops.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "columns", new_columns_str, -1));
if (ast_to_str(current_metadata->settings_changes) != ast_to_str(future_metadata.settings_changes))
{
/// Just change settings
StorageInMemoryMetadata metadata_copy = *current_metadata;
metadata_copy.settings_changes = future_metadata.settings_changes;
changeSettings(metadata_copy.settings_changes, table_lock_holder);
DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(query_context, table_id, metadata_copy);
}
/// We can be sure, that in case of successful commit in zookeeper our
/// version will increments by 1. Because we update with version check.
int new_metadata_version = metadata_version + 1;
alter_entry->type = LogEntry::ALTER_METADATA;
alter_entry->source_replica = replica_name;
alter_entry->metadata_str = new_metadata_str;
alter_entry->columns_str = new_columns_str;
alter_entry->alter_version = new_metadata_version;
alter_entry->create_time = time(nullptr);
auto maybe_mutation_commands = commands.getMutationCommands(
*current_metadata, query_context->getSettingsRef().materialize_ttl_after_modify, query_context);
bool have_mutation = !maybe_mutation_commands.empty();
alter_entry->have_mutation = have_mutation;
alter_path_idx = ops.size();
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(zookeeper_path) / "log/log-", alter_entry->toString(), zkutil::CreateMode::PersistentSequential));
PartitionBlockNumbersHolder partition_block_numbers_holder;
if (have_mutation)
{
const String mutations_path(fs::path(zookeeper_path) / "mutations");
ReplicatedMergeTreeMutationEntry mutation_entry;
mutation_entry.alter_version = new_metadata_version;
mutation_entry.source_replica = replica_name;
mutation_entry.commands = std::move(maybe_mutation_commands);
Coordination::Stat mutations_stat;
zookeeper->get(mutations_path, &mutations_stat);
partition_block_numbers_holder =
allocateBlockNumbersInAffectedPartitions(mutation_entry.commands, query_context, zookeeper);
mutation_entry.block_numbers = partition_block_numbers_holder.getBlockNumbers();
mutation_entry.create_time = time(nullptr);
ops.emplace_back(zkutil::makeSetRequest(mutations_path, String(), mutations_stat.version));
mutation_path_idx = ops.size();
ops.emplace_back(
zkutil::makeCreateRequest(fs::path(mutations_path) / "", mutation_entry.toString(), zkutil::CreateMode::PersistentSequential));
}
if (auto txn = query_context->getZooKeeperMetadataTransaction())
{
/// It would be better to clone ops instead of moving, so we could retry on ZBADVERSION,
/// but clone() is not implemented for Coordination::Request.
txn->moveOpsTo(ops);
/// NOTE: IDatabase::alterTable(...) is called when executing ALTER_METADATA queue entry without query context,
/// so we have to update metadata of DatabaseReplicated here.
String metadata_zk_path = fs::path(txn->getDatabaseZooKeeperPath()) / "metadata" / escapeForFileName(table_id.table_name);
auto ast = DatabaseCatalog::instance().getDatabase(table_id.database_name)->getCreateTableQuery(table_id.table_name, query_context);
applyMetadataChangesToCreateQuery(ast, future_metadata);
ops.emplace_back(zkutil::makeSetRequest(metadata_zk_path, getObjectDefinitionFromCreateQuery(ast), -1));
}
Coordination::Responses results;
Coordination::Error rc = zookeeper->tryMulti(ops, results);
/// For the sake of constitency with mechanics of concurrent background process of assigning parts merge tasks
/// this placeholder must be held up until the moment of committing into ZK of the mutation entry
/// See ReplicatedMergeTreeMergePredicate::canMergeTwoParts() method
partition_block_numbers_holder.reset();
if (rc == Coordination::Error::ZOK)
{
if (have_mutation)
{
/// ALTER_METADATA record in replication /log
String alter_path = dynamic_cast<const Coordination::CreateResponse &>(*results[alter_path_idx]).path_created;
alter_entry->znode_name = alter_path.substr(alter_path.find_last_of('/') + 1);
/// ReplicatedMergeTreeMutationEntry record in /mutations
String mutation_path = dynamic_cast<const Coordination::CreateResponse &>(*results[mutation_path_idx]).path_created;
mutation_znode = mutation_path.substr(mutation_path.find_last_of('/') + 1);
}
else
{
/// ALTER_METADATA record in replication /log
String alter_path = dynamic_cast<const Coordination::CreateResponse &>(*results[alter_path_idx]).path_created;
alter_entry->znode_name = alter_path.substr(alter_path.find_last_of('/') + 1);
}
break;
}
else if (rc == Coordination::Error::ZBADVERSION)
{
if (results[0]->error != Coordination::Error::ZOK)
throw Exception("Metadata on replica is not up to date with common metadata in Zookeeper. It means that this replica still not applied some of previous alters."
" Probably too many alters executing concurrently (highly not recommended). You can retry this error",
ErrorCodes::CANNOT_ASSIGN_ALTER);
/// Cannot retry automatically, because some zookeeper ops were lost on the first attempt. Will retry on DDLWorker-level.
if (query_context->getZooKeeperMetadataTransaction())
throw Exception("Cannot execute alter, because mutations version was suddenly changed due to concurrent alter",
ErrorCodes::CANNOT_ASSIGN_ALTER);
continue;
}
else
{
throw Coordination::Exception("Alter cannot be assigned because of Zookeeper error", rc);
}
}
table_lock_holder.unlock();
LOG_DEBUG(log, "Updated shared metadata nodes in ZooKeeper. Waiting for replicas to apply changes.");
waitForLogEntryToBeProcessedIfNecessary(*alter_entry, query_context, "Some replicas doesn't finish metadata alter: ");
if (mutation_znode)
{
LOG_DEBUG(log, "Metadata changes applied. Will wait for data changes.");
waitMutation(*mutation_znode, query_context->getSettingsRef().replication_alter_partitions_sync);
LOG_DEBUG(log, "Data changes applied.");
}
}
/// If new version returns ordinary name, else returns part name containing the first and last month of the month
/// NOTE: use it in pair with getFakePartCoveringAllPartsInPartition(...)
String getPartNamePossiblyFake(MergeTreeDataFormatVersion format_version, const MergeTreePartInfo & part_info)
{
if (format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
{
/// The date range is all month long.
const auto & lut = DateLUT::instance();
time_t start_time = lut.YYYYMMDDToDate(parse<UInt32>(part_info.partition_id + "01"));
DayNum left_date = DayNum(lut.toDayNum(start_time).toUnderType());
DayNum right_date = DayNum(static_cast<size_t>(left_date) + lut.daysInMonth(start_time) - 1);
return part_info.getPartNameV0(left_date, right_date);
}
return part_info.getPartName();
}
bool StorageReplicatedMergeTree::getFakePartCoveringAllPartsInPartition(const String & partition_id, MergeTreePartInfo & part_info,
std::optional<EphemeralLockInZooKeeper> & delimiting_block_lock, bool for_replace_range)
{
/// Even if there is no data in the partition, you still need to mark the range for deletion.
/// - Because before executing DETACH, tasks for downloading parts to this partition can be executed.
Int64 left = 0;
/** Let's skip one number in `block_numbers` for the partition being deleted, and we will only delete parts until this number.
* This prohibits merges of deleted parts with the new inserted
* Invariant: merges of deleted parts with other parts do not appear in the log.
* NOTE: If you need to similarly support a `DROP PART` request, you will have to think of some new mechanism for it,
* to guarantee this invariant.
*/
Int64 right;
Int64 mutation_version;
{
auto zookeeper = getZooKeeper();
delimiting_block_lock = allocateBlockNumber(partition_id, zookeeper);
right = delimiting_block_lock->getNumber();
/// Make sure we cover all parts in drop range.
/// There might be parts with mutation version greater than current block number
/// if some part mutation has been assigned after block number allocation, but before creation of DROP_RANGE entry.
mutation_version = MergeTreePartInfo::MAX_BLOCK_NUMBER;
}
if (for_replace_range)
{
/// NOTE Do not decrement max block number for REPLACE_RANGE, because there are invariants:
/// - drop range for REPLACE PARTITION must contain at least 2 blocks (1 skipped block and at least 1 real block)
/// - drop range for MOVE PARTITION/ATTACH PARTITION FROM always contains 1 block
/// NOTE UINT_MAX was previously used as max level for REPLACE/MOVE PARTITION (it was incorrect)
part_info = MergeTreePartInfo(partition_id, left, right, MergeTreePartInfo::MAX_LEVEL, mutation_version);
return right != 0;
}
/// Empty partition.
if (right == 0)
return false;
--right;
/// Artificial high level is chosen, to make this part "covering" all parts inside.
part_info = MergeTreePartInfo(partition_id, left, right, MergeTreePartInfo::MAX_LEVEL, mutation_version);
return true;
}
void StorageReplicatedMergeTree::restoreMetadataInZooKeeper()
{
LOG_INFO(log, "Restoring replica metadata");
if (!is_readonly)
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Replica must be readonly");
if (getZooKeeper()->exists(replica_path))
throw Exception(ErrorCodes::BAD_ARGUMENTS,
"Replica path is present at {} - nothing to restore. "
"If you are sure that metadata is lost and that replica path contains some garbage, "
"then use SYSTEM DROP REPLICA query first.", replica_path);
if (has_metadata_in_zookeeper.has_value() && *has_metadata_in_zookeeper)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Replica has metadata in ZooKeeper: "
"it's either a bug or it's a result of manual intervention to ZooKeeper");
if (are_restoring_replica.exchange(true))
throw Exception(ErrorCodes::CONCURRENT_ACCESS_NOT_SUPPORTED, "Replica restoration in progress");
SCOPE_EXIT({ are_restoring_replica.store(false); });
auto metadata_snapshot = getInMemoryMetadataPtr();
const DataPartsVector all_parts = getAllDataPartsVector();
Strings active_parts_names;
/// Why all parts (not only Active) are moved to detached/:
/// After ZK metadata restoration ZK resets sequential counters (including block number counters), so one may
/// potentially encounter a situation that a part we want to attach already exists.
for (const auto & part : all_parts)
{
if (part->getState() == DataPartState::Active)
active_parts_names.push_back(part->name);
forgetPartAndMoveToDetached(part);
}
LOG_INFO(log, "Moved all parts to detached/");
const bool is_first_replica = createTableIfNotExists(metadata_snapshot);
LOG_INFO(log, "Created initial ZK nodes, replica is first: {}", is_first_replica);
if (!is_first_replica)
createReplica(metadata_snapshot);
createNewZooKeeperNodes();
LOG_INFO(log, "Created ZK nodes for table");
has_metadata_in_zookeeper = true;
if (is_first_replica)
for (const String& part_name : active_parts_names)
attachPartition(std::make_shared<ASTLiteral>(part_name), metadata_snapshot, true, getContext());
LOG_INFO(log, "Attached all partitions, starting table");
startup();
}
void StorageReplicatedMergeTree::dropPartNoWaitNoThrow(const String & part_name)
{
assertNotReadonly();
if (!is_leader)
throw Exception("DROP PART cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
zkutil::ZooKeeperPtr zookeeper = getZooKeeperAndAssertNotReadonly();
LogEntry entry;
dropPartImpl(zookeeper, part_name, entry, /*detach=*/ false, /*throw_if_noop=*/ false);
}
void StorageReplicatedMergeTree::dropPart(const String & part_name, bool detach, ContextPtr query_context)
{
assertNotReadonly();
if (!is_leader)
throw Exception("DROP PART cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
zkutil::ZooKeeperPtr zookeeper = getZooKeeperAndAssertNotReadonly();
LogEntry entry;
dropPartImpl(zookeeper, part_name, entry, detach, /*throw_if_noop=*/ true);
waitForLogEntryToBeProcessedIfNecessary(entry, query_context);
}
void StorageReplicatedMergeTree::dropPartition(const ASTPtr & partition, bool detach, ContextPtr query_context)
{
assertNotReadonly();
if (!is_leader)
throw Exception("DROP PARTITION cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
zkutil::ZooKeeperPtr zookeeper = getZooKeeperAndAssertNotReadonly();
LogEntry entry;
String partition_id = getPartitionIDFromQuery(partition, query_context);
bool did_drop = dropAllPartsInPartition(*zookeeper, partition_id, entry, query_context, detach);
if (did_drop)
{
waitForLogEntryToBeProcessedIfNecessary(entry, query_context);
cleanLastPartNode(partition_id);
}
}
void StorageReplicatedMergeTree::truncate(
const ASTPtr &, const StorageMetadataPtr &, ContextPtr query_context, TableExclusiveLockHolder & table_lock)
{
table_lock.release(); /// Truncate is done asynchronously.
assertNotReadonly();
if (!is_leader)
throw Exception("TRUNCATE cannot be done on this replica because it is not a leader", ErrorCodes::NOT_A_LEADER);
zkutil::ZooKeeperPtr zookeeper = getZooKeeperAndAssertNotReadonly();
Strings partitions = zookeeper->getChildren(fs::path(zookeeper_path) / "block_numbers");
std::vector<std::unique_ptr<LogEntry>> entries_to_wait;
entries_to_wait.reserve(partitions.size());
for (String & partition_id : partitions)
{
auto entry = std::make_unique<LogEntry>();
if (dropAllPartsInPartition(*zookeeper, partition_id, *entry, query_context, false))
entries_to_wait.push_back(std::move(entry));
}
for (const auto & entry : entries_to_wait)
waitForLogEntryToBeProcessedIfNecessary(*entry, query_context);
}
PartitionCommandsResultInfo StorageReplicatedMergeTree::attachPartition(
const ASTPtr & partition,
const StorageMetadataPtr & metadata_snapshot,
bool attach_part,
ContextPtr query_context)
{
/// Allow ATTACH PARTITION on readonly replica when restoring it.
if (!are_restoring_replica)
assertNotReadonly();
PartitionCommandsResultInfo results;
PartsTemporaryRename renamed_parts(*this, "detached/");
MutableDataPartsVector loaded_parts = tryLoadPartsToAttach(partition, attach_part, query_context, renamed_parts);
/// TODO Allow to use quorum here.
ReplicatedMergeTreeSink output(*this, metadata_snapshot, 0, 0, 0, false, false, query_context,
/*is_attach*/true);
for (size_t i = 0; i < loaded_parts.size(); ++i)
{
const String old_name = loaded_parts[i]->name;
output.writeExistingPart(loaded_parts[i]);
renamed_parts.old_and_new_names[i].old_name.clear();
LOG_DEBUG(log, "Attached part {} as {}", old_name, loaded_parts[i]->name);
results.push_back(PartitionCommandResultInfo{
.partition_id = loaded_parts[i]->info.partition_id,
.part_name = loaded_parts[i]->name,
.old_part_name = old_name,
});
}
return results;
}
void StorageReplicatedMergeTree::checkTableCanBeDropped() const
{
auto table_id = getStorageID();
getContext()->checkTableCanBeDropped(table_id.database_name, table_id.table_name, getTotalActiveSizeInBytes());
}
void StorageReplicatedMergeTree::checkTableCanBeRenamed() const
{
if (!allow_renaming)
throw Exception("Cannot rename Replicated table, because zookeeper_path contains implicit 'database' or 'table' macro. "
"We cannot rename path in ZooKeeper, so path may become inconsistent with table name. If you really want to rename table, "
"you should edit metadata file first and restart server or reattach the table.", ErrorCodes::NOT_IMPLEMENTED);
}
void StorageReplicatedMergeTree::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
{
checkTableCanBeRenamed();
MergeTreeData::rename(new_path_to_table_data, new_table_id);
/// Update table name in zookeeper
if (!is_readonly)
{
/// We don't do it for readonly tables, because it will be updated on next table startup.
/// It is also Ok to skip ZK error for the same reason.
try
{
auto zookeeper = getZooKeeper();
zookeeper->set(fs::path(replica_path) / "host", getReplicatedMergeTreeAddress().toString());
}
catch (Coordination::Exception & e)
{
LOG_WARNING(log, "Cannot update the value of 'host' node (replica address) in ZooKeeper: {}", e.displayText());
}
}
/// TODO: You can update names of loggers.
}
bool StorageReplicatedMergeTree::existsNodeCached(const std::string & path) const
{
{
std::lock_guard lock(existing_nodes_cache_mutex);
if (existing_nodes_cache.count(path))
return true;
}
bool res = getZooKeeper()->exists(path);
if (res)
{
std::lock_guard lock(existing_nodes_cache_mutex);
existing_nodes_cache.insert(path);
}
return res;
}
std::optional<EphemeralLockInZooKeeper>
StorageReplicatedMergeTree::allocateBlockNumber(
const String & partition_id, const zkutil::ZooKeeperPtr & zookeeper, const String & zookeeper_block_id_path, const String & zookeeper_path_prefix) const
{
String zookeeper_table_path;
if (zookeeper_path_prefix.empty())
zookeeper_table_path = zookeeper_path;
else
zookeeper_table_path = zookeeper_path_prefix;
/// Lets check for duplicates in advance, to avoid superfluous block numbers allocation
Coordination::Requests deduplication_check_ops;
if (!zookeeper_block_id_path.empty())
{
deduplication_check_ops.emplace_back(zkutil::makeCreateRequest(zookeeper_block_id_path, "", zkutil::CreateMode::Persistent));
deduplication_check_ops.emplace_back(zkutil::makeRemoveRequest(zookeeper_block_id_path, -1));
}
String block_numbers_path = fs::path(zookeeper_table_path) / "block_numbers";
String partition_path = fs::path(block_numbers_path) / partition_id;
if (!existsNodeCached(partition_path))
{
Coordination::Requests ops;
ops.push_back(zkutil::makeCreateRequest(partition_path, "", zkutil::CreateMode::Persistent));
/// We increment data version of the block_numbers node so that it becomes possible
/// to check in a ZK transaction that the set of partitions didn't change
/// (unfortunately there is no CheckChildren op).
ops.push_back(zkutil::makeSetRequest(block_numbers_path, "", -1));
Coordination::Responses responses;
Coordination::Error code = zookeeper->tryMulti(ops, responses);
if (code != Coordination::Error::ZOK && code != Coordination::Error::ZNODEEXISTS)
zkutil::KeeperMultiException::check(code, ops, responses);
}
EphemeralLockInZooKeeper lock;
/// 2 RTT
try
{
lock = EphemeralLockInZooKeeper(
fs::path(partition_path) / "block-", fs::path(zookeeper_table_path) / "temp", *zookeeper, &deduplication_check_ops);
}
catch (const zkutil::KeeperMultiException & e)
{
if (e.code == Coordination::Error::ZNODEEXISTS && e.getPathForFirstFailedOp() == zookeeper_block_id_path)
return {};
throw Exception("Cannot allocate block number in ZooKeeper: " + e.displayText(), ErrorCodes::KEEPER_EXCEPTION);
}
catch (const Coordination::Exception & e)
{
throw Exception("Cannot allocate block number in ZooKeeper: " + e.displayText(), ErrorCodes::KEEPER_EXCEPTION);
}
return {std::move(lock)};
}
Strings StorageReplicatedMergeTree::tryWaitForAllReplicasToProcessLogEntry(
const String & table_zookeeper_path, const ReplicatedMergeTreeLogEntryData & entry, Int64 wait_for_inactive_timeout)
{
LOG_DEBUG(log, "Waiting for all replicas to process {}", entry.znode_name);
auto zookeeper = getZooKeeper();
Strings replicas = zookeeper->getChildren(fs::path(table_zookeeper_path) / "replicas");
Strings unwaited;
bool wait_for_inactive = wait_for_inactive_timeout != 0;
for (const String & replica : replicas)
{
if (wait_for_inactive || zookeeper->exists(fs::path(table_zookeeper_path) / "replicas" / replica / "is_active"))
{
if (!tryWaitForReplicaToProcessLogEntry(table_zookeeper_path, replica, entry, wait_for_inactive_timeout))
unwaited.push_back(replica);
}
else
{
unwaited.push_back(replica);
}
}
LOG_DEBUG(log, "Finished waiting for all replicas to process {}", entry.znode_name);
return unwaited;
}
void StorageReplicatedMergeTree::waitForAllReplicasToProcessLogEntry(
const String & table_zookeeper_path, const ReplicatedMergeTreeLogEntryData & entry, Int64 wait_for_inactive_timeout, const String & error_context)
{
Strings unfinished_replicas = tryWaitForAllReplicasToProcessLogEntry(table_zookeeper_path, entry, wait_for_inactive_timeout);
if (unfinished_replicas.empty())
return;
throw Exception(ErrorCodes::UNFINISHED, "{}Timeout exceeded while waiting for replicas {} to process entry {}. "
"Probably some replicas are inactive", error_context, fmt::join(unfinished_replicas, ", "), entry.znode_name);
}
void StorageReplicatedMergeTree::waitForLogEntryToBeProcessedIfNecessary(const ReplicatedMergeTreeLogEntryData & entry, ContextPtr query_context, const String & error_context)
{
/// If necessary, wait until the operation is performed on itself or on all replicas.
Int64 wait_for_inactive_timeout = query_context->getSettingsRef().replication_wait_for_inactive_replica_timeout;
if (query_context->getSettingsRef().replication_alter_partitions_sync == 1)
{
bool finished = tryWaitForReplicaToProcessLogEntry(zookeeper_path, replica_name, entry, wait_for_inactive_timeout);
if (!finished)
{
throw Exception(ErrorCodes::UNFINISHED, "{}Log entry {} is not precessed on local replica, "
"most likely because the replica was shut down.", error_context, entry.znode_name);
}
}
else if (query_context->getSettingsRef().replication_alter_partitions_sync == 2)
{
waitForAllReplicasToProcessLogEntry(zookeeper_path, entry, wait_for_inactive_timeout, error_context);
}
}
bool StorageReplicatedMergeTree::tryWaitForReplicaToProcessLogEntry(
const String & table_zookeeper_path, const String & replica, const ReplicatedMergeTreeLogEntryData & entry, Int64 wait_for_inactive_timeout)
{
String entry_str = entry.toString();
String log_node_name;
/** Wait for entries from `log` directory (a common log, from where replicas copy entries to their queue) to be processed.
*
* The problem is that the numbers (`sequential` node) of the queue elements in `log` and in `queue` do not match.
* (And the numbers of the same log element for different replicas do not match in the `queue`.)
*/
/** First, you need to wait until replica takes `queue` element from the `log` to its queue,
* if it has not been done already (see the `pullLogsToQueue` function).
*
* To do this, check its node `log_pointer` - the maximum number of the element taken from `log` + 1.
*/
bool waiting_itself = replica == replica_name;
/// Do not wait if timeout is zero
bool wait_for_inactive = wait_for_inactive_timeout != 0;
/// Wait for unlimited time if timeout is negative
bool check_timeout = wait_for_inactive_timeout > 0;
Stopwatch time_waiting;
const auto & stop_waiting = [&]()
{
bool stop_waiting_itself = waiting_itself && partial_shutdown_called;
bool timeout_exceeded = check_timeout && wait_for_inactive_timeout < time_waiting.elapsedSeconds();
bool stop_waiting_inactive = (!wait_for_inactive || timeout_exceeded)
&& !getZooKeeper()->exists(fs::path(table_zookeeper_path) / "replicas" / replica / "is_active");
return is_dropped || stop_waiting_itself || stop_waiting_inactive;
};
/// Don't recheck ZooKeeper too often
constexpr auto event_wait_timeout_ms = 3000;
LOG_DEBUG(log, "Waiting for {} to process log entry", replica);
if (startsWith(entry.znode_name, "log-"))
{
/// Take the number from the node name `log-xxxxxxxxxx`.
UInt64 log_index = parse<UInt64>(entry.znode_name.substr(entry.znode_name.size() - 10));
log_node_name = entry.znode_name;
LOG_DEBUG(log, "Waiting for {} to pull {} to queue", replica, log_node_name);
/// Let's wait until entry gets into the replica queue.
bool pulled_to_queue = false;
do
{
zkutil::EventPtr event = std::make_shared<Poco::Event>();
String log_pointer = getZooKeeper()->get(fs::path(table_zookeeper_path) / "replicas" / replica / "log_pointer", nullptr, event);
if (!log_pointer.empty() && parse<UInt64>(log_pointer) > log_index)
{
pulled_to_queue = true;
break;
}
/// Wait with timeout because we can be already shut down, but not dropped.
/// So log_pointer node will exist, but we will never update it because all background threads already stopped.
/// It can lead to query hung because table drop query can wait for some query (alter, optimize, etc) which called this method,
/// but the query will never finish because the drop already shut down the table.
if (!stop_waiting())
event->tryWait(event_wait_timeout_ms);
} while (!stop_waiting());
if (!pulled_to_queue)
return false;
LOG_DEBUG(log, "Looking for node corresponding to {} in {} queue", log_node_name, replica);
}
else if (!entry.log_entry_id.empty())
{
/// First pass, check the table log.
/// If found in the log, wait for replica to fetch it to the queue.
/// If not found in the log, it is already in the queue.
LOG_DEBUG(log, "Looking for log entry with id `{}` in the log", entry.log_entry_id);
String log_pointer = getZooKeeper()->get(fs::path(table_zookeeper_path) / "replicas" / replica / "log_pointer");
Strings log_entries = getZooKeeper()->getChildren(fs::path(table_zookeeper_path) / "log");
UInt64 log_index = 0;
bool found = false;
for (const String & log_entry_name : log_entries)
{
log_index = parse<UInt64>(log_entry_name.substr(log_entry_name.size() - 10));
if (!log_pointer.empty() && log_index < parse<UInt64>(log_pointer))
continue;
String log_entry_str;
Coordination::Stat log_entry_stat;
bool exists = getZooKeeper()->tryGet(fs::path(table_zookeeper_path) / "log" / log_entry_name, log_entry_str, &log_entry_stat);
ReplicatedMergeTreeLogEntryData log_entry = *ReplicatedMergeTreeLogEntry::parse(log_entry_str, log_entry_stat);
if (exists && entry.log_entry_id == log_entry.log_entry_id)
{
LOG_DEBUG(log, "Found log entry with id `{}` in the log", entry.log_entry_id);
found = true;
log_node_name = log_entry_name;
break;
}
}
if (found)
{
LOG_DEBUG(log, "Waiting for {} to pull {} to queue", replica, log_node_name);
/// Let's wait until entry gets into the replica queue.
bool pulled_to_queue = false;
do
{
zkutil::EventPtr event = std::make_shared<Poco::Event>();
log_pointer = getZooKeeper()->get(fs::path(table_zookeeper_path) / "replicas" / replica / "log_pointer", nullptr, event);
if (!log_pointer.empty() && parse<UInt64>(log_pointer) > log_index)
{
pulled_to_queue = true;
break;
}
/// Wait with timeout because we can be already shut down, but not dropped.
/// So log_pointer node will exist, but we will never update it because all background threads already stopped.
/// It can lead to query hung because table drop query can wait for some query (alter, optimize, etc) which called this method,
/// but the query will never finish because the drop already shut down the table.
if (!stop_waiting())
event->tryWait(event_wait_timeout_ms);
} while (!stop_waiting());
if (!pulled_to_queue)
return false;
}
}
else
{
throw Exception("Logical error: unexpected name of log node: " + entry.znode_name, ErrorCodes::LOGICAL_ERROR);
}
/** Second - find the corresponding entry in the queue of the specified replica.
* Its number may not match the `log` node. Therefore, we search by comparing the content.
*/
Strings queue_entries = getZooKeeper()->getChildren(fs::path(table_zookeeper_path) / "replicas" / replica / "queue");
String queue_entry_to_wait_for;
for (const String & entry_name : queue_entries)
{
String queue_entry_str;
Coordination::Stat queue_entry_stat;
bool exists = getZooKeeper()->tryGet(fs::path(table_zookeeper_path) / "replicas" / replica / "queue" / entry_name, queue_entry_str, &queue_entry_stat);
if (exists && queue_entry_str == entry_str)
{
queue_entry_to_wait_for = entry_name;
break;
}
else if (!entry.log_entry_id.empty())
{
/// Check if the id matches rather than just contents. This entry
/// might have been written by different ClickHouse versions and
/// it is hard to guarantee same text representation.
ReplicatedMergeTreeLogEntryData queue_entry = *ReplicatedMergeTreeLogEntry::parse(queue_entry_str, queue_entry_stat);
if (entry.log_entry_id == queue_entry.log_entry_id)
{
queue_entry_to_wait_for = entry_name;
break;
}
}
}
/// While looking for the record, it has already been executed and deleted.
if (queue_entry_to_wait_for.empty())
{
LOG_DEBUG(log, "No corresponding node found. Assuming it has been already processed. Found {} nodes", queue_entries.size());
return true;
}
LOG_DEBUG(log, "Waiting for {} to disappear from {} queue", queue_entry_to_wait_for, replica);
/// Third - wait until the entry disappears from the replica queue or replica become inactive.
String path_to_wait_on = fs::path(table_zookeeper_path) / "replicas" / replica / "queue" / queue_entry_to_wait_for;
return getZooKeeper()->waitForDisappear(path_to_wait_on, stop_waiting);
}
void StorageReplicatedMergeTree::getStatus(Status & res, bool with_zk_fields)
{
auto zookeeper = tryGetZooKeeper();
const auto storage_settings_ptr = getSettings();
res.is_leader = is_leader;
res.can_become_leader = storage_settings_ptr->replicated_can_become_leader;
res.is_readonly = is_readonly;
res.is_session_expired = !zookeeper || zookeeper->expired();
res.queue = queue.getStatus();
res.absolute_delay = getAbsoluteDelay(); /// NOTE: may be slightly inconsistent with queue status.
res.parts_to_check = part_check_thread.size();
res.zookeeper_path = zookeeper_path;
res.replica_name = replica_name;
res.replica_path = replica_path;
res.columns_version = -1;
res.log_max_index = 0;
res.log_pointer = 0;
res.total_replicas = 0;
res.active_replicas = 0;
res.last_queue_update_exception = getLastQueueUpdateException();
if (with_zk_fields && !res.is_session_expired)
{
try
{
auto log_entries = zookeeper->getChildren(fs::path(zookeeper_path) / "log");
if (!log_entries.empty())
{
const String & last_log_entry = *std::max_element(log_entries.begin(), log_entries.end());
res.log_max_index = parse<UInt64>(last_log_entry.substr(strlen("log-")));
}
String log_pointer_str = zookeeper->get(fs::path(replica_path) / "log_pointer");
res.log_pointer = log_pointer_str.empty() ? 0 : parse<UInt64>(log_pointer_str);
auto all_replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
res.total_replicas = all_replicas.size();
for (const String & replica : all_replicas)
{
bool is_replica_active = zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active");
res.active_replicas += static_cast<UInt8>(is_replica_active);
res.replica_is_active.emplace(replica, is_replica_active);
}
}
catch (const Coordination::Exception &)
{
res.zookeeper_exception = getCurrentExceptionMessage(false);
}
}
}
void StorageReplicatedMergeTree::getQueue(LogEntriesData & res, String & replica_name_)
{
replica_name_ = replica_name;
queue.getEntries(res);
}
std::vector<PartMovesBetweenShardsOrchestrator::Entry> StorageReplicatedMergeTree::getPartMovesBetweenShardsEntries()
{
return part_moves_between_shards_orchestrator.getEntries();
}
time_t StorageReplicatedMergeTree::getAbsoluteDelay() const
{
time_t min_unprocessed_insert_time = 0;
time_t max_processed_insert_time = 0;
queue.getInsertTimes(min_unprocessed_insert_time, max_processed_insert_time);
/// Load start time, then finish time to avoid reporting false delay when start time is updated
/// between loading of two variables.
time_t queue_update_start_time = last_queue_update_start_time.load();
time_t queue_update_finish_time = last_queue_update_finish_time.load();
time_t current_time = time(nullptr);
if (!queue_update_finish_time)
{
/// We have not updated queue even once yet (perhaps replica is readonly).
/// As we have no info about the current state of replication log, return effectively infinite delay.
return current_time;
}
else if (min_unprocessed_insert_time)
{
/// There are some unprocessed insert entries in queue.
return (current_time > min_unprocessed_insert_time) ? (current_time - min_unprocessed_insert_time) : 0;
}
else if (queue_update_start_time > queue_update_finish_time)
{
/// Queue is empty, but there are some in-flight or failed queue update attempts
/// (likely because of problems with connecting to ZooKeeper).
/// Return the time passed since last attempt.
return (current_time > queue_update_start_time) ? (current_time - queue_update_start_time) : 0;
}
else
{
/// Everything is up-to-date.
return 0;
}
}
void StorageReplicatedMergeTree::getReplicaDelays(time_t & out_absolute_delay, time_t & out_relative_delay)
{
assertNotReadonly();
time_t current_time = time(nullptr);
out_absolute_delay = getAbsoluteDelay();
out_relative_delay = 0;
const auto storage_settings_ptr = getSettings();
/** Relative delay is the maximum difference of absolute delay from any other replica,
* (if this replica lags behind any other live replica, or zero, otherwise).
* Calculated only if the absolute delay is large enough.
*/
if (out_absolute_delay < static_cast<time_t>(storage_settings_ptr->min_relative_delay_to_measure))
return;
auto zookeeper = getZooKeeper();
time_t max_replicas_unprocessed_insert_time = 0;
bool have_replica_with_nothing_unprocessed = false;
Strings replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
for (const auto & replica : replicas)
{
if (replica == replica_name)
continue;
/// Skip dead replicas.
if (!zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active"))
continue;
String value;
if (!zookeeper->tryGet(fs::path(zookeeper_path) / "replicas" / replica / "min_unprocessed_insert_time", value))
continue;
time_t replica_time = value.empty() ? 0 : parse<time_t>(value);
if (replica_time == 0)
{
/** Note
* The conclusion that the replica does not lag may be incorrect,
* because the information about `min_unprocessed_insert_time` is taken
* only from that part of the log that has been moved to the queue.
* If the replica for some reason has stalled `queueUpdatingTask`,
* then `min_unprocessed_insert_time` will be incorrect.
*/
have_replica_with_nothing_unprocessed = true;
break;
}
if (replica_time > max_replicas_unprocessed_insert_time)
max_replicas_unprocessed_insert_time = replica_time;
}
if (have_replica_with_nothing_unprocessed)
out_relative_delay = out_absolute_delay;
else
{
max_replicas_unprocessed_insert_time = std::min(current_time, max_replicas_unprocessed_insert_time);
time_t min_replicas_delay = current_time - max_replicas_unprocessed_insert_time;
if (out_absolute_delay > min_replicas_delay)
out_relative_delay = out_absolute_delay - min_replicas_delay;
}
}
void StorageReplicatedMergeTree::fetchPartition(
const ASTPtr & partition,
const StorageMetadataPtr & metadata_snapshot,
const String & from_,
bool fetch_part,
ContextPtr query_context)
{
Macros::MacroExpansionInfo info;
info.expand_special_macros_only = false; //-V1048
info.table_id = getStorageID();
info.table_id.uuid = UUIDHelpers::Nil;
auto expand_from = query_context->getMacros()->expand(from_, info);
String auxiliary_zookeeper_name = zkutil::extractZooKeeperName(expand_from);
String from = zkutil::extractZooKeeperPath(expand_from, /* check_starts_with_slash */ true);
if (from.empty())
throw Exception("ZooKeeper path should not be empty", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
zkutil::ZooKeeperPtr zookeeper;
if (auxiliary_zookeeper_name != default_zookeeper_name)
zookeeper = getContext()->getAuxiliaryZooKeeper(auxiliary_zookeeper_name);
else
zookeeper = getZooKeeper();
if (from.back() == '/')
from.resize(from.size() - 1);
if (fetch_part)
{
String part_name = partition->as<ASTLiteral &>().value.safeGet<String>();
auto part_path = findReplicaHavingPart(part_name, from, zookeeper);
if (part_path.empty())
throw Exception(ErrorCodes::NO_REPLICA_HAS_PART, "Part {} does not exist on any replica", part_name);
/** Let's check that there is no such part in the `detached` directory (where we will write the downloaded parts).
* Unreliable (there is a race condition) - such a part may appear a little later.
*/
if (checkIfDetachedPartExists(part_name))
throw Exception(ErrorCodes::DUPLICATE_DATA_PART, "Detached part " + part_name + " already exists.");
LOG_INFO(log, "Will fetch part {} from shard {} (zookeeper '{}')", part_name, from_, auxiliary_zookeeper_name);
try
{
/// part name , metadata, part_path , true, 0, zookeeper
if (!fetchPart(part_name, metadata_snapshot, part_path, true, 0, zookeeper))
throw Exception(ErrorCodes::UNFINISHED, "Failed to fetch part {} from {}", part_name, from_);
}
catch (const DB::Exception & e)
{
if (e.code() != ErrorCodes::RECEIVED_ERROR_FROM_REMOTE_IO_SERVER && e.code() != ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS
&& e.code() != ErrorCodes::CANNOT_READ_ALL_DATA)
throw;
LOG_INFO(log, fmt::runtime(e.displayText()));
}
return;
}
String partition_id = getPartitionIDFromQuery(partition, query_context);
LOG_INFO(log, "Will fetch partition {} from shard {} (zookeeper '{}')", partition_id, from_, auxiliary_zookeeper_name);
/** Let's check that there is no such partition in the `detached` directory (where we will write the downloaded parts).
* Unreliable (there is a race condition) - such a partition may appear a little later.
*/
if (checkIfDetachedPartitionExists(partition_id))
throw Exception("Detached partition " + partition_id + " already exists.", ErrorCodes::PARTITION_ALREADY_EXISTS);
zkutil::Strings replicas;
zkutil::Strings active_replicas;
String best_replica;
{
/// List of replicas of source shard.
replicas = zookeeper->getChildren(fs::path(from) / "replicas");
/// Leave only active replicas.
active_replicas.reserve(replicas.size());
for (const String & replica : replicas)
if (zookeeper->exists(fs::path(from) / "replicas" / replica / "is_active"))
active_replicas.push_back(replica);
if (active_replicas.empty())
throw Exception("No active replicas for shard " + from, ErrorCodes::NO_ACTIVE_REPLICAS);
/** You must select the best (most relevant) replica.
* This is a replica with the maximum `log_pointer`, then with the minimum `queue` size.
* NOTE This is not exactly the best criteria. It does not make sense to download old partitions,
* and it would be nice to be able to choose the replica closest by network.
* NOTE Of course, there are data races here. You can solve it by retrying.
*/
Int64 max_log_pointer = -1;
UInt64 min_queue_size = std::numeric_limits<UInt64>::max();
for (const String & replica : active_replicas)
{
String current_replica_path = fs::path(from) / "replicas" / replica;
String log_pointer_str = zookeeper->get(fs::path(current_replica_path) / "log_pointer");
Int64 log_pointer = log_pointer_str.empty() ? 0 : parse<UInt64>(log_pointer_str);
Coordination::Stat stat;
zookeeper->get(fs::path(current_replica_path) / "queue", &stat);
size_t queue_size = stat.numChildren;
if (log_pointer > max_log_pointer
|| (log_pointer == max_log_pointer && queue_size < min_queue_size))
{
max_log_pointer = log_pointer;
min_queue_size = queue_size;
best_replica = replica;
}
}
}
if (best_replica.empty())
throw Exception("Logical error: cannot choose best replica.", ErrorCodes::LOGICAL_ERROR);
LOG_INFO(log, "Found {} replicas, {} of them are active. Selected {} to fetch from.", replicas.size(), active_replicas.size(), best_replica);
String best_replica_path = fs::path(from) / "replicas" / best_replica;
/// Let's find out which parts are on the best replica.
/** Trying to download these parts.
* Some of them could be deleted due to the merge.
* In this case, update the information about the available parts and try again.
*/
unsigned try_no = 0;
Strings missing_parts;
do
{
if (try_no)
LOG_INFO(log, "Some of parts ({}) are missing. Will try to fetch covering parts.", missing_parts.size());
if (try_no >= query_context->getSettings().max_fetch_partition_retries_count)
throw Exception("Too many retries to fetch parts from " + best_replica_path, ErrorCodes::TOO_MANY_RETRIES_TO_FETCH_PARTS);
Strings parts = zookeeper->getChildren(fs::path(best_replica_path) / "parts");
ActiveDataPartSet active_parts_set(format_version, parts);
Strings parts_to_fetch;
if (missing_parts.empty())
{
parts_to_fetch = active_parts_set.getParts();
/// Leaving only the parts of the desired partition.
Strings parts_to_fetch_partition;
for (const String & part : parts_to_fetch)
{
if (MergeTreePartInfo::fromPartName(part, format_version).partition_id == partition_id)
parts_to_fetch_partition.push_back(part);
}
parts_to_fetch = std::move(parts_to_fetch_partition);
if (parts_to_fetch.empty())
throw Exception("Partition " + partition_id + " on " + best_replica_path + " doesn't exist", ErrorCodes::PARTITION_DOESNT_EXIST);
}
else
{
for (const String & missing_part : missing_parts)
{
String containing_part = active_parts_set.getContainingPart(missing_part);
if (!containing_part.empty())
parts_to_fetch.push_back(containing_part);
else
LOG_WARNING(log, "Part {} on replica {} has been vanished.", missing_part, best_replica_path);
}
}
LOG_INFO(log, "Parts to fetch: {}", parts_to_fetch.size());
missing_parts.clear();
for (const String & part : parts_to_fetch)
{
bool fetched = false;
try
{
fetched = fetchPart(part, metadata_snapshot, best_replica_path, true, 0, zookeeper);
}
catch (const DB::Exception & e)
{
if (e.code() != ErrorCodes::RECEIVED_ERROR_FROM_REMOTE_IO_SERVER && e.code() != ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS
&& e.code() != ErrorCodes::CANNOT_READ_ALL_DATA)
throw;
LOG_INFO(log, fmt::runtime(e.displayText()));
}
if (!fetched)
missing_parts.push_back(part);
}
++try_no;
} while (!missing_parts.empty());
}
void StorageReplicatedMergeTree::mutate(const MutationCommands & commands, ContextPtr query_context)
{
/// Overview of the mutation algorithm.
///
/// When the client executes a mutation, this method is called. It acquires block numbers in all
/// partitions, saves them in the mutation entry and writes the mutation entry to a new ZK node in
/// the /mutations folder. This block numbers are needed to determine which parts should be mutated and
/// which shouldn't (parts inserted after the mutation will have the block number higher than the
/// block number acquired by the mutation in that partition and so will not be mutatied).
/// This block number is called "mutation version" in that partition.
///
/// Mutation versions are acquired atomically in all partitions, so the case when an insert in some
/// partition has the block number higher than the mutation version but the following insert into another
/// partition acquires the block number lower than the mutation version in that partition is impossible.
/// Another important invariant: mutation entries appear in /mutations in the order of their mutation
/// versions (in any partition). This means that mutations form a sequence and we can execute them in
/// the order of their mutation versions and not worry that some mutation with the smaller version
/// will suddenly appear.
///
/// During mutations individual parts are immutable - when we want to change the contents of a part
/// we prepare the new part and add it to MergeTreeData (the original part gets replaced). The fact that
/// we have mutated the part is recorded in the part->info.mutation field of MergeTreePartInfo.
/// The relation with the original part is preserved because the new part covers the same block range
/// as the original one.
///
/// We then can for each part determine its "mutation version": the version of the last mutation in
/// the mutation sequence that we regard as already applied to that part. All mutations with the greater
/// version number will still need to be applied to that part.
///
/// Execution of mutations is done asynchronously. All replicas watch the /mutations directory and
/// load new mutation entries as they appear (see mutationsUpdatingTask()). Next we need to determine
/// how to mutate individual parts consistently with part merges. This is done by the leader replica
/// (see mergeSelectingTask() and class ReplicatedMergeTreeMergePredicate for details). Important
/// invariants here are that a) all source parts for a single merge must have the same mutation version
/// and b) any part can be mutated only once or merged only once (e.g. once we have decided to mutate
/// a part then we need to execute that mutation and can assign merges only to the new part and not to the
/// original part). Multiple consecutive mutations can be executed at once (without writing the
/// intermediate result to a part).
///
/// Leader replica records its decisions to the replication log (/log directory in ZK) in the form of
/// MUTATE_PART entries and all replicas then execute them in the background pool
/// (see MutateTask class). When a replica encounters a MUTATE_PART command, it is
/// guaranteed that the corresponding mutation entry is already loaded (when we pull entries from
/// replication log into the replica queue, we also load mutation entries). Note that just as with merges
/// the replica can decide not to do the mutation locally and fetch the mutated part from another replica
/// instead.
///
/// Mutations of individual parts are in fact pretty similar to merges, e.g. their assignment and execution
/// is governed by the same storage_settings. TODO: support a single "merge-mutation" operation when the data
/// read from the the source parts is first mutated on the fly to some uniform mutation version and then
/// merged to a resulting part.
///
/// After all needed parts are mutated (i.e. all active parts have the mutation version greater than
/// the version of this mutation), the mutation is considered done and can be deleted.
ReplicatedMergeTreeMutationEntry mutation_entry;
mutation_entry.source_replica = replica_name;
mutation_entry.commands = commands;
const String mutations_path = fs::path(zookeeper_path) / "mutations";
const auto zookeeper = getZooKeeper();
/// Update the mutations_path node when creating the mutation and check its version to ensure that
/// nodes for mutations are created in the same order as the corresponding block numbers.
/// Should work well if the number of concurrent mutation requests is small.
while (true)
{
Coordination::Stat mutations_stat;
zookeeper->get(mutations_path, &mutations_stat);
PartitionBlockNumbersHolder partition_block_numbers_holder =
allocateBlockNumbersInAffectedPartitions(mutation_entry.commands, query_context, zookeeper);
mutation_entry.block_numbers = partition_block_numbers_holder.getBlockNumbers();
mutation_entry.create_time = time(nullptr);
/// The following version check guarantees the linearizability property for any pair of mutations:
/// mutation with higher sequence number is guaranteed to have higher block numbers in every partition
/// (and thus will be applied strictly according to sequence numbers of mutations)
Coordination::Requests requests;
requests.emplace_back(zkutil::makeSetRequest(mutations_path, String(), mutations_stat.version));
requests.emplace_back(zkutil::makeCreateRequest(
fs::path(mutations_path) / "", mutation_entry.toString(), zkutil::CreateMode::PersistentSequential));
if (auto txn = query_context->getZooKeeperMetadataTransaction())
txn->moveOpsTo(requests);
Coordination::Responses responses;
Coordination::Error rc = zookeeper->tryMulti(requests, responses);
partition_block_numbers_holder.reset();
if (rc == Coordination::Error::ZOK)
{
const String & path_created =
dynamic_cast<const Coordination::CreateResponse *>(responses[1].get())->path_created;
mutation_entry.znode_name = path_created.substr(path_created.find_last_of('/') + 1);
LOG_TRACE(log, "Created mutation with ID {}", mutation_entry.znode_name);
break;
}
else if (rc == Coordination::Error::ZBADVERSION)
{
/// Cannot retry automatically, because some zookeeper ops were lost on the first attempt. Will retry on DDLWorker-level.
if (query_context->getZooKeeperMetadataTransaction())
throw Exception("Cannot execute alter, because mutations version was suddenly changed due to concurrent alter",
ErrorCodes::CANNOT_ASSIGN_ALTER);
LOG_TRACE(log, "Version conflict when trying to create a mutation node, retrying...");
continue;
}
else
throw Coordination::Exception("Unable to create a mutation znode", rc);
}
waitMutation(mutation_entry.znode_name, query_context->getSettingsRef().mutations_sync);
}
void StorageReplicatedMergeTree::waitMutation(const String & znode_name, size_t mutations_sync) const
{
if (!mutations_sync)
return;
/// we have to wait
auto zookeeper = getZooKeeper();
Strings replicas;
if (mutations_sync == 2) /// wait for all replicas
{
replicas = zookeeper->getChildren(fs::path(zookeeper_path) / "replicas");
/// This replica should be first, to ensure that the mutation will be loaded into memory
for (auto it = replicas.begin(); it != replicas.end(); ++it)
{
if (*it == replica_name)
{
std::iter_swap(it, replicas.rbegin());
break;
}
}
}
else if (mutations_sync == 1) /// just wait for ourself
replicas.push_back(replica_name);
waitMutationToFinishOnReplicas(replicas, znode_name);
}
std::vector<MergeTreeMutationStatus> StorageReplicatedMergeTree::getMutationsStatus() const
{
return queue.getMutationsStatus();
}
CancellationCode StorageReplicatedMergeTree::killMutation(const String & mutation_id)
{
assertNotReadonly();
zkutil::ZooKeeperPtr zookeeper = getZooKeeperAndAssertNotReadonly();
LOG_INFO(log, "Killing mutation {}", mutation_id);
auto mutation_entry = queue.removeMutation(zookeeper, mutation_id);
if (!mutation_entry)
return CancellationCode::NotFound;
/// After this point no new part mutations will start and part mutations that still exist
/// in the queue will be skipped.
/// Cancel already running part mutations.
for (const auto & pair : mutation_entry->block_numbers)
{
const String & partition_id = pair.first;
Int64 block_number = pair.second;
getContext()->getMergeList().cancelPartMutations(getStorageID(), partition_id, block_number);
}
return CancellationCode::CancelSent;
}
void StorageReplicatedMergeTree::clearOldPartsAndRemoveFromZK()
{
auto table_lock = lockForShare(
RWLockImpl::NO_QUERY, getSettings()->lock_acquire_timeout_for_background_operations);
auto zookeeper = getZooKeeper();
DataPartsVector parts = grabOldParts();
if (parts.empty())
return;
DataPartsVector parts_to_delete_only_from_filesystem; // Only duplicates
DataPartsVector parts_to_delete_completely; // All parts except duplicates
DataPartsVector parts_to_retry_deletion; // Parts that should be retried due to network problems
DataPartsVector parts_to_remove_from_filesystem; // Parts removed from ZK
for (const auto & part : parts)
{
if (!part->is_duplicate)
parts_to_delete_completely.emplace_back(part);
else
parts_to_delete_only_from_filesystem.emplace_back(part);
}
parts.clear();
/// Delete duplicate parts from filesystem
if (!parts_to_delete_only_from_filesystem.empty())
{
clearPartsFromFilesystem(parts_to_delete_only_from_filesystem);
removePartsFinally(parts_to_delete_only_from_filesystem);
LOG_DEBUG(log, "Removed {} old duplicate parts", parts_to_delete_only_from_filesystem.size());
}
/// Delete normal parts from ZooKeeper
NameSet part_names_to_retry_deletion;
try
{
Strings part_names_to_delete_completely;
for (const auto & part : parts_to_delete_completely)
part_names_to_delete_completely.emplace_back(part->name);
LOG_DEBUG(log, "Removing {} old parts from ZooKeeper", parts_to_delete_completely.size());
removePartsFromZooKeeper(zookeeper, part_names_to_delete_completely, &part_names_to_retry_deletion);
}
catch (...)
{
LOG_ERROR(log, "There is a problem with deleting parts from ZooKeeper: {}", getCurrentExceptionMessage(true));
}
/// Part names that were reliably deleted from ZooKeeper should be deleted from filesystem
auto num_reliably_deleted_parts = parts_to_delete_completely.size() - part_names_to_retry_deletion.size();
LOG_DEBUG(log, "Removed {} old parts from ZooKeeper. Removing them from filesystem.", num_reliably_deleted_parts);
/// Delete normal parts on two sets
for (auto & part : parts_to_delete_completely)
{
if (part_names_to_retry_deletion.count(part->name) == 0)
parts_to_remove_from_filesystem.emplace_back(part);
else
parts_to_retry_deletion.emplace_back(part);
}
/// Will retry deletion
if (!parts_to_retry_deletion.empty())
{
rollbackDeletingParts(parts_to_retry_deletion);
LOG_DEBUG(log, "Will retry deletion of {} parts in the next time", parts_to_retry_deletion.size());
}
/// Remove parts from filesystem and finally from data_parts
if (!parts_to_remove_from_filesystem.empty())
{
clearPartsFromFilesystem(parts_to_remove_from_filesystem);
removePartsFinally(parts_to_remove_from_filesystem);
LOG_DEBUG(log, "Removed {} old parts", parts_to_remove_from_filesystem.size());
}
}
void StorageReplicatedMergeTree::removePartsFromZooKeeperWithRetries(DataPartsVector & parts, size_t max_retries)
{
Strings part_names_to_remove;
for (const auto & part : parts)
part_names_to_remove.emplace_back(part->name);
return removePartsFromZooKeeperWithRetries(part_names_to_remove, max_retries);
}
void StorageReplicatedMergeTree::removePartsFromZooKeeperWithRetries(const Strings & part_names, size_t max_retries)
{
size_t num_tries = 0;
bool success = false;
while (!success && (max_retries == 0 || num_tries < max_retries))
{
try
{
++num_tries;
success = true;
auto zookeeper = getZooKeeper();
std::vector<std::future<Coordination::ExistsResponse>> exists_futures;
exists_futures.reserve(part_names.size());
for (const String & part_name : part_names)
{
String part_path = fs::path(replica_path) / "parts" / part_name;
exists_futures.emplace_back(zookeeper->asyncExists(part_path));
}
std::vector<std::future<Coordination::MultiResponse>> remove_futures;
remove_futures.reserve(part_names.size());
for (size_t i = 0; i < part_names.size(); ++i)
{
Coordination::ExistsResponse exists_resp = exists_futures[i].get();
if (exists_resp.error == Coordination::Error::ZOK)
{
Coordination::Requests ops;
removePartFromZooKeeper(part_names[i], ops, exists_resp.stat.numChildren > 0);
remove_futures.emplace_back(zookeeper->asyncTryMultiNoThrow(ops));
}
}
for (auto & future : remove_futures)
{
auto response = future.get();
if (response.error == Coordination::Error::ZOK || response.error == Coordination::Error::ZNONODE)
continue;
if (Coordination::isHardwareError(response.error))
{
success = false;
continue;
}
throw Coordination::Exception(response.error);
}
}
catch (Coordination::Exception & e)
{
success = false;
if (Coordination::isHardwareError(e.code))
tryLogCurrentException(log, __PRETTY_FUNCTION__);
else
throw;
}
if (!success && num_tries < max_retries)
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
}
if (!success)
throw Exception(ErrorCodes::UNFINISHED, "Failed to remove parts from ZooKeeper after {} retries", num_tries);
}
void StorageReplicatedMergeTree::removePartsFromZooKeeper(
zkutil::ZooKeeperPtr & zookeeper, const Strings & part_names, NameSet * parts_should_be_retried)
{
std::vector<std::future<Coordination::ExistsResponse>> exists_futures;
std::vector<std::future<Coordination::MultiResponse>> remove_futures;
exists_futures.reserve(part_names.size());
remove_futures.reserve(part_names.size());
try
{
/// Exception can be thrown from loop
/// if zk session will be dropped
for (const String & part_name : part_names)
{
String part_path = fs::path(replica_path) / "parts" / part_name;
exists_futures.emplace_back(zookeeper->asyncExists(part_path));
}
for (size_t i = 0; i < part_names.size(); ++i)
{
Coordination::ExistsResponse exists_resp = exists_futures[i].get();
if (exists_resp.error == Coordination::Error::ZOK)
{
Coordination::Requests ops;
removePartFromZooKeeper(part_names[i], ops, exists_resp.stat.numChildren > 0);
remove_futures.emplace_back(zookeeper->asyncTryMultiNoThrow(ops));
}
else
{
LOG_DEBUG(log, "There is no part {} in ZooKeeper, it was only in filesystem", part_names[i]);
// emplace invalid future so that the total number of futures is the same as part_names.size();
remove_futures.emplace_back();
}
}
}
catch (const Coordination::Exception & e)
{
if (parts_should_be_retried && Coordination::isHardwareError(e.code))
parts_should_be_retried->insert(part_names.begin(), part_names.end());
throw;
}
for (size_t i = 0; i < remove_futures.size(); ++i)
{
auto & future = remove_futures[i];
if (!future.valid())
continue;
auto response = future.get();
if (response.error == Coordination::Error::ZOK)
continue;
else if (response.error == Coordination::Error::ZNONODE)
{
LOG_DEBUG(log, "There is no part {} in ZooKeeper, it was only in filesystem", part_names[i]);
continue;
}
else if (Coordination::isHardwareError(response.error))
{
if (parts_should_be_retried)
parts_should_be_retried->insert(part_names[i]);
continue;
}
else
LOG_WARNING(log, "Cannot remove part {} from ZooKeeper: {}", part_names[i], Coordination::errorMessage(response.error));
}
}
void StorageReplicatedMergeTree::getClearBlocksInPartitionOps(
Coordination::Requests & ops, zkutil::ZooKeeper & zookeeper, const String & partition_id, Int64 min_block_num, Int64 max_block_num)
{
Strings blocks;
if (Coordination::Error::ZOK != zookeeper.tryGetChildren(fs::path(zookeeper_path) / "blocks", blocks))
throw Exception(zookeeper_path + "/blocks doesn't exist", ErrorCodes::NOT_FOUND_NODE);
String partition_prefix = partition_id + "_";
zkutil::AsyncResponses<Coordination::GetResponse> get_futures;
for (const String & block_id : blocks)
{
if (startsWith(block_id, partition_prefix))
{
String path = fs::path(zookeeper_path) / "blocks" / block_id;
get_futures.emplace_back(path, zookeeper.asyncTryGet(path));
}
}
for (auto & pair : get_futures)
{
const String & path = pair.first;
auto result = pair.second.get();
if (result.error == Coordination::Error::ZNONODE)
continue;
ReadBufferFromString buf(result.data);
const auto part_info = MergeTreePartInfo::tryParsePartName(result.data, format_version);
if (!part_info || (min_block_num <= part_info->min_block && part_info->max_block <= max_block_num))
ops.emplace_back(zkutil::makeRemoveRequest(path, -1));
}
}
void StorageReplicatedMergeTree::clearBlocksInPartition(
zkutil::ZooKeeper & zookeeper, const String & partition_id, Int64 min_block_num, Int64 max_block_num)
{
Coordination::Requests delete_requests;
getClearBlocksInPartitionOps(delete_requests, zookeeper, partition_id, min_block_num, max_block_num);
Coordination::Responses delete_responses;
auto code = zookeeper.tryMulti(delete_requests, delete_responses);
if (code != Coordination::Error::ZOK)
{
for (size_t i = 0; i < delete_requests.size(); ++i)
if (delete_responses[i]->error != Coordination::Error::ZOK)
LOG_WARNING(log, "Error while deleting ZooKeeper path `{}`: {}, ignoring.", delete_requests[i]->getPath(), Coordination::errorMessage(delete_responses[i]->error));
}
LOG_TRACE(log, "Deleted {} deduplication block IDs in partition ID {}", delete_requests.size(), partition_id);
}
void StorageReplicatedMergeTree::replacePartitionFrom(
const StoragePtr & source_table, const ASTPtr & partition, bool replace, ContextPtr query_context)
{
/// First argument is true, because we possibly will add new data to current table.
auto lock1 = lockForShare(query_context->getCurrentQueryId(), query_context->getSettingsRef().lock_acquire_timeout);
auto lock2 = source_table->lockForShare(query_context->getCurrentQueryId(), query_context->getSettingsRef().lock_acquire_timeout);
auto source_metadata_snapshot = source_table->getInMemoryMetadataPtr();
auto metadata_snapshot = getInMemoryMetadataPtr();
Stopwatch watch;
MergeTreeData & src_data = checkStructureAndGetMergeTreeData(source_table, source_metadata_snapshot, metadata_snapshot);
String partition_id = getPartitionIDFromQuery(partition, query_context);
/// NOTE: Some covered parts may be missing in src_all_parts if corresponding log entries are not executed yet.
DataPartsVector src_all_parts = src_data.getDataPartsVectorInPartition(MergeTreeDataPartState::Active, partition_id);
LOG_DEBUG(log, "Cloning {} parts", src_all_parts.size());
static const String TMP_PREFIX = "tmp_replace_from_";
auto zookeeper = getZooKeeper();
/// Retry if alter_partition_version changes
for (size_t retry = 0; retry < 1000; ++retry)
{
DataPartsVector src_parts;
MutableDataPartsVector dst_parts;
Strings block_id_paths;
Strings part_checksums;
std::vector<EphemeralLockInZooKeeper> ephemeral_locks;
String alter_partition_version_path = zookeeper_path + "/alter_partition_version";
Coordination::Stat alter_partition_version_stat;
zookeeper->get(alter_partition_version_path, &alter_partition_version_stat);
/// Firstly, generate last block number and compute drop_range
/// NOTE: Even if we make ATTACH PARTITION instead of REPLACE PARTITION drop_range will not be empty, it will contain a block.
/// So, such case has special meaning, if drop_range contains only one block it means that nothing to drop.
/// TODO why not to add normal DROP_RANGE entry to replication queue if `replace` is true?
MergeTreePartInfo drop_range;
std::optional<EphemeralLockInZooKeeper> delimiting_block_lock;
bool partition_was_empty = !getFakePartCoveringAllPartsInPartition(partition_id, drop_range, delimiting_block_lock, true);
if (replace && partition_was_empty)
{
/// Nothing to drop, will just attach new parts
LOG_INFO(log, "Partition {} was empty, REPLACE PARTITION will work as ATTACH PARTITION FROM", drop_range.partition_id);
replace = false;
}
if (!replace)
{
/// It's ATTACH PARTITION FROM, not REPLACE PARTITION. We have to reset drop range
drop_range = makeDummyDropRangeForMovePartitionOrAttachPartitionFrom(partition_id);
}
assert(replace == !LogEntry::ReplaceRangeEntry::isMovePartitionOrAttachFrom(drop_range));
String drop_range_fake_part_name = getPartNamePossiblyFake(format_version, drop_range);
for (const auto & src_part : src_all_parts)
{
/// We also make some kind of deduplication to avoid duplicated parts in case of ATTACH PARTITION
/// Assume that merges in the partition are quite rare
/// Save deduplication block ids with special prefix replace_partition
if (!canReplacePartition(src_part))
throw Exception(
"Cannot replace partition '" + partition_id + "' because part '" + src_part->name + "' has inconsistent granularity with table",
ErrorCodes::LOGICAL_ERROR);
String hash_hex = src_part->checksums.getTotalChecksumHex();
if (replace)
LOG_INFO(log, "Trying to replace {} with hash_hex {}", src_part->name, hash_hex);
else
LOG_INFO(log, "Trying to attach {} with hash_hex {}", src_part->name, hash_hex);
String block_id_path = replace ? "" : (fs::path(zookeeper_path) / "blocks" / (partition_id + "_replace_from_" + hash_hex));
auto lock = allocateBlockNumber(partition_id, zookeeper, block_id_path);
if (!lock)
{
LOG_INFO(log, "Part {} (hash {}) has been already attached", src_part->name, hash_hex);
continue;
}
UInt64 index = lock->getNumber();
MergeTreePartInfo dst_part_info(partition_id, index, index, src_part->info.level);
auto dst_part = cloneAndLoadDataPartOnSameDisk(src_part, TMP_PREFIX, dst_part_info, metadata_snapshot);
src_parts.emplace_back(src_part);
dst_parts.emplace_back(dst_part);
ephemeral_locks.emplace_back(std::move(*lock));
block_id_paths.emplace_back(block_id_path);
part_checksums.emplace_back(hash_hex);
}
ReplicatedMergeTreeLogEntryData entry;
{
auto src_table_id = src_data.getStorageID();
entry.type = ReplicatedMergeTreeLogEntryData::REPLACE_RANGE;
entry.source_replica = replica_name;
entry.create_time = time(nullptr);
entry.replace_range_entry = std::make_shared<ReplicatedMergeTreeLogEntryData::ReplaceRangeEntry>();
auto & entry_replace = *entry.replace_range_entry;
entry_replace.drop_range_part_name = drop_range_fake_part_name;
entry_replace.from_database = src_table_id.database_name;
entry_replace.from_table = src_table_id.table_name;
for (const auto & part : src_parts)
entry_replace.src_part_names.emplace_back(part->name);
for (const auto & part : dst_parts)
entry_replace.new_part_names.emplace_back(part->name);
for (const String & checksum : part_checksums)
entry_replace.part_names_checksums.emplace_back(checksum);
entry_replace.columns_version = -1;
}
/// Remove deduplication block_ids of replacing parts
if (replace)
clearBlocksInPartition(*zookeeper, drop_range.partition_id, drop_range.max_block, drop_range.max_block);
DataPartsVector parts_to_remove;
Coordination::Responses op_results;
try
{
Coordination::Requests ops;
for (size_t i = 0; i < dst_parts.size(); ++i)
{
getCommitPartOps(ops, dst_parts[i], block_id_paths[i]);
ephemeral_locks[i].getUnlockOps(ops);
}
if (auto txn = query_context->getZooKeeperMetadataTransaction())
txn->moveOpsTo(ops);
delimiting_block_lock->getUnlockOps(ops);
/// Check and update version to avoid race with DROP_RANGE
ops.emplace_back(zkutil::makeSetRequest(alter_partition_version_path, "", alter_partition_version_stat.version));
/// Just update version, because merges assignment relies on it
ops.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "log", "", -1));
ops.emplace_back(zkutil::makeCreateRequest(fs::path(zookeeper_path) / "log/log-", entry.toString(), zkutil::CreateMode::PersistentSequential));
Transaction transaction(*this);
{
auto data_parts_lock = lockParts();
for (MutableDataPartPtr & part : dst_parts)
renameTempPartAndReplace(part, nullptr, &transaction, data_parts_lock);
}
Coordination::Error code = zookeeper->tryMulti(ops, op_results);
if (code == Coordination::Error::ZOK)
delimiting_block_lock->assumeUnlocked();
else if (code == Coordination::Error::ZBADVERSION)
{
/// Cannot retry automatically, because some zookeeper ops were lost on the first attempt. Will retry on DDLWorker-level.
if (query_context->getZooKeeperMetadataTransaction())
throw Exception(
"Cannot execute alter, because alter partition version was suddenly changed due to concurrent alter",
ErrorCodes::CANNOT_ASSIGN_ALTER);
continue;
}
else
zkutil::KeeperMultiException::check(code, ops, op_results);
{
auto data_parts_lock = lockParts();
transaction.commit(&data_parts_lock);
if (replace)
parts_to_remove = removePartsInRangeFromWorkingSet(drop_range, true, data_parts_lock);
}
PartLog::addNewParts(getContext(), dst_parts, watch.elapsed());
}
catch (...)
{
PartLog::addNewParts(getContext(), dst_parts, watch.elapsed(), ExecutionStatus::fromCurrentException());
throw;
}
String log_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*op_results.back()).path_created;
entry.znode_name = log_znode_path.substr(log_znode_path.find_last_of('/') + 1);
for (auto & lock : ephemeral_locks)
lock.assumeUnlocked();
/// Forcibly remove replaced parts from ZooKeeper
removePartsFromZooKeeperWithRetries(parts_to_remove);
/// Speedup removing of replaced parts from filesystem
parts_to_remove.clear();
cleanup_thread.wakeup();
lock2.reset();
lock1.reset();
waitForLogEntryToBeProcessedIfNecessary(entry, query_context);
return;
}
throw Exception(
ErrorCodes::CANNOT_ASSIGN_ALTER, "Cannot assign ALTER PARTITION, because another ALTER PARTITION query was concurrently executed");
}
void StorageReplicatedMergeTree::movePartitionToTable(const StoragePtr & dest_table, const ASTPtr & partition, ContextPtr query_context)
{
auto lock1 = lockForShare(query_context->getCurrentQueryId(), query_context->getSettingsRef().lock_acquire_timeout);
auto lock2 = dest_table->lockForShare(query_context->getCurrentQueryId(), query_context->getSettingsRef().lock_acquire_timeout);
auto dest_table_storage = std::dynamic_pointer_cast<StorageReplicatedMergeTree>(dest_table);
if (!dest_table_storage)
throw Exception("Table " + getStorageID().getNameForLogs() + " supports movePartitionToTable only for ReplicatedMergeTree family of table engines."
" Got " + dest_table->getName(), ErrorCodes::NOT_IMPLEMENTED);
if (dest_table_storage->getStoragePolicy() != this->getStoragePolicy())
throw Exception("Destination table " + dest_table_storage->getStorageID().getNameForLogs() +
" should have the same storage policy of source table " + getStorageID().getNameForLogs() + ". " +
getStorageID().getNameForLogs() + ": " + this->getStoragePolicy()->getName() + ", " +
getStorageID().getNameForLogs() + ": " + dest_table_storage->getStoragePolicy()->getName(), ErrorCodes::UNKNOWN_POLICY);
auto dest_metadata_snapshot = dest_table->getInMemoryMetadataPtr();
auto metadata_snapshot = getInMemoryMetadataPtr();
Stopwatch watch;
MergeTreeData & src_data = dest_table_storage->checkStructureAndGetMergeTreeData(*this, metadata_snapshot, dest_metadata_snapshot);
auto src_data_id = src_data.getStorageID();
String partition_id = getPartitionIDFromQuery(partition, query_context);
/// A range for log entry to remove parts from the source table (myself).
auto zookeeper = getZooKeeper();
/// Retry if alter_partition_version changes
for (size_t retry = 0; retry < 1000; ++retry)
{
String alter_partition_version_path = zookeeper_path + "/alter_partition_version";
Coordination::Stat alter_partition_version_stat;
zookeeper->get(alter_partition_version_path, &alter_partition_version_stat);
MergeTreePartInfo drop_range;
std::optional<EphemeralLockInZooKeeper> delimiting_block_lock;
getFakePartCoveringAllPartsInPartition(partition_id, drop_range, delimiting_block_lock, true);
String drop_range_fake_part_name = getPartNamePossiblyFake(format_version, drop_range);
DataPartPtr covering_part;
DataPartsVector src_all_parts;
{
/// NOTE: Some covered parts may be missing in src_all_parts if corresponding log entries are not executed yet.
auto parts_lock = src_data.lockParts();
src_all_parts = src_data.getActivePartsToReplace(drop_range, drop_range_fake_part_name, covering_part, parts_lock);
}
if (covering_part)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Got part {} covering drop range {}, it's a bug",
covering_part->name, drop_range_fake_part_name);
/// After allocating block number for drop_range we must ensure that it does not intersect block numbers
/// allocated by concurrent REPLACE query.
/// We could check it in multi-request atomically with creation of DROP_RANGE entry in source table log,
/// but it's better to check it here and fail as early as possible (before we have done something to destination table).
Coordination::Error version_check_code = zookeeper->trySet(alter_partition_version_path, "", alter_partition_version_stat.version);
if (version_check_code != Coordination::Error::ZOK)
throw Exception(ErrorCodes::CANNOT_ASSIGN_ALTER, "Cannot DROP PARTITION in {} after copying partition to {}, "
"because another ALTER PARTITION query was concurrently executed",
getStorageID().getFullTableName(), dest_table_storage->getStorageID().getFullTableName());
DataPartsVector src_parts;
MutableDataPartsVector dst_parts;
Strings block_id_paths;
Strings part_checksums;
std::vector<EphemeralLockInZooKeeper> ephemeral_locks;
LOG_DEBUG(log, "Cloning {} parts", src_all_parts.size());
static const String TMP_PREFIX = "tmp_move_from_";
/// Clone parts into destination table.
String dest_alter_partition_version_path = dest_table_storage->zookeeper_path + "/alter_partition_version";
Coordination::Stat dest_alter_partition_version_stat;
zookeeper->get(dest_alter_partition_version_path, &dest_alter_partition_version_stat);
for (const auto & src_part : src_all_parts)
{
if (!dest_table_storage->canReplacePartition(src_part))
throw Exception(
"Cannot move partition '" + partition_id + "' because part '" + src_part->name + "' has inconsistent granularity with table",
ErrorCodes::LOGICAL_ERROR);
String hash_hex = src_part->checksums.getTotalChecksumHex();
String block_id_path;
auto lock = dest_table_storage->allocateBlockNumber(partition_id, zookeeper, block_id_path);
if (!lock)
{
LOG_INFO(log, "Part {} (hash {}) has been already attached", src_part->name, hash_hex);
continue;
}
UInt64 index = lock->getNumber();
MergeTreePartInfo dst_part_info(partition_id, index, index, src_part->info.level);
auto dst_part = dest_table_storage->cloneAndLoadDataPartOnSameDisk(src_part, TMP_PREFIX, dst_part_info, dest_metadata_snapshot);
src_parts.emplace_back(src_part);
dst_parts.emplace_back(dst_part);
ephemeral_locks.emplace_back(std::move(*lock));
block_id_paths.emplace_back(block_id_path);
part_checksums.emplace_back(hash_hex);
}
ReplicatedMergeTreeLogEntryData entry_delete;
{
entry_delete.type = LogEntry::DROP_RANGE;
entry_delete.source_replica = replica_name;
entry_delete.new_part_name = drop_range_fake_part_name;
entry_delete.detach = false; //-V1048
entry_delete.create_time = time(nullptr);
}
ReplicatedMergeTreeLogEntryData entry;
{
MergeTreePartInfo drop_range_dest = makeDummyDropRangeForMovePartitionOrAttachPartitionFrom(partition_id);
entry.type = ReplicatedMergeTreeLogEntryData::REPLACE_RANGE;
entry.source_replica = dest_table_storage->replica_name;
entry.create_time = time(nullptr);
entry.replace_range_entry = std::make_shared<ReplicatedMergeTreeLogEntryData::ReplaceRangeEntry>();
auto & entry_replace = *entry.replace_range_entry;
entry_replace.drop_range_part_name = getPartNamePossiblyFake(format_version, drop_range_dest);
entry_replace.from_database = src_data_id.database_name;
entry_replace.from_table = src_data_id.table_name;
for (const auto & part : src_parts)
entry_replace.src_part_names.emplace_back(part->name);
for (const auto & part : dst_parts)
entry_replace.new_part_names.emplace_back(part->name);
for (const String & checksum : part_checksums)
entry_replace.part_names_checksums.emplace_back(checksum);
entry_replace.columns_version = -1;
}
clearBlocksInPartition(*zookeeper, drop_range.partition_id, drop_range.max_block, drop_range.max_block);
DataPartsVector parts_to_remove;
Coordination::Responses op_results;
try
{
Coordination::Requests ops;
for (size_t i = 0; i < dst_parts.size(); ++i)
{
dest_table_storage->getCommitPartOps(ops, dst_parts[i], block_id_paths[i]);
ephemeral_locks[i].getUnlockOps(ops);
}
/// Check and update version to avoid race with DROP_RANGE
ops.emplace_back(zkutil::makeSetRequest(dest_alter_partition_version_path, "", dest_alter_partition_version_stat.version));
/// Just update version, because merges assignment relies on it
ops.emplace_back(zkutil::makeSetRequest(fs::path(dest_table_storage->zookeeper_path) / "log", "", -1));
ops.emplace_back(zkutil::makeCreateRequest(fs::path(dest_table_storage->zookeeper_path) / "log/log-",
entry.toString(), zkutil::CreateMode::PersistentSequential));
{
Transaction transaction(*dest_table_storage);
auto src_data_parts_lock = lockParts();
auto dest_data_parts_lock = dest_table_storage->lockParts();
std::mutex mutex;
DataPartsLock lock(mutex);
for (MutableDataPartPtr & part : dst_parts)
dest_table_storage->renameTempPartAndReplace(part, nullptr, &transaction, lock);
Coordination::Error code = zookeeper->tryMulti(ops, op_results);
if (code == Coordination::Error::ZBADVERSION)
continue;
else
zkutil::KeeperMultiException::check(code, ops, op_results);
parts_to_remove = removePartsInRangeFromWorkingSet(drop_range, true, lock);
transaction.commit(&lock);
}
PartLog::addNewParts(getContext(), dst_parts, watch.elapsed());
}
catch (...)
{
PartLog::addNewParts(getContext(), dst_parts, watch.elapsed(), ExecutionStatus::fromCurrentException());
throw;
}
String log_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*op_results.back()).path_created;
entry.znode_name = log_znode_path.substr(log_znode_path.find_last_of('/') + 1);
for (auto & lock : ephemeral_locks)
lock.assumeUnlocked();
removePartsFromZooKeeperWithRetries(parts_to_remove);
parts_to_remove.clear();
cleanup_thread.wakeup();
lock2.reset();
dest_table_storage->waitForLogEntryToBeProcessedIfNecessary(entry, query_context);
/// Create DROP_RANGE for the source table
Coordination::Requests ops_src;
ops_src.emplace_back(zkutil::makeCreateRequest(
fs::path(zookeeper_path) / "log/log-", entry_delete.toString(), zkutil::CreateMode::PersistentSequential));
/// Just update version, because merges assignment relies on it
ops_src.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "log", "", -1));
delimiting_block_lock->getUnlockOps(ops_src);
op_results = zookeeper->multi(ops_src);
log_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*op_results.front()).path_created;
entry_delete.znode_name = log_znode_path.substr(log_znode_path.find_last_of('/') + 1);
lock1.reset();
waitForLogEntryToBeProcessedIfNecessary(entry_delete, query_context);
/// Cleaning possibly stored information about parts from /quorum/last_part node in ZooKeeper.
cleanLastPartNode(partition_id);
return;
}
throw Exception(ErrorCodes::CANNOT_ASSIGN_ALTER, "Cannot assign ALTER PARTITION, because another ALTER PARTITION query was concurrently executed");
}
void StorageReplicatedMergeTree::movePartitionToShard(
const ASTPtr & partition, bool move_part, const String & to, ContextPtr /*query_context*/)
{
/// This is a lightweight operation that only optimistically checks if it could succeed and queues tasks.
if (!move_part)
throw Exception("MOVE PARTITION TO SHARD is not supported, use MOVE PART instead", ErrorCodes::NOT_IMPLEMENTED);
if (zkutil::normalizeZooKeeperPath(zookeeper_path, /* check_starts_with_slash */ true) == zkutil::normalizeZooKeeperPath(to, /* check_starts_with_slash */ true))
throw Exception("Source and destination are the same", ErrorCodes::BAD_ARGUMENTS);
auto zookeeper = getZooKeeperAndAssertNotReadonly();
String part_name = partition->as<ASTLiteral &>().value.safeGet<String>();
auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
auto part = getPartIfExists(part_info, {MergeTreeDataPartState::Active});
if (!part)
throw Exception(ErrorCodes::NO_SUCH_DATA_PART, "Part {} not found locally", part_name);
if (part->uuid == UUIDHelpers::Nil)
throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Part {} does not have an uuid assigned and it can't be moved between shards", part_name);
ReplicatedMergeTreeMergePredicate merge_pred = queue.getMergePredicate(zookeeper);
/// The following block is pretty much copy & paste from StorageReplicatedMergeTree::dropPart to avoid conflicts while this is WIP.
/// Extract it to a common method and re-use it before merging.
{
if (partIsLastQuorumPart(part->info))
{
throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Part {} is last inserted part with quorum in partition. Would not be able to drop", part_name);
}
/// canMergeSinglePart is overlapping with dropPart, let's try to use the same code.
String out_reason;
if (!merge_pred.canMergeSinglePart(part, &out_reason))
throw Exception(ErrorCodes::PART_IS_TEMPORARILY_LOCKED, "Part is busy, reason: " + out_reason);
}
{
/// Optimistic check that for compatible destination table structure.
checkTableStructure(to, getInMemoryMetadataPtr());
}
PinnedPartUUIDs src_pins;
PinnedPartUUIDs dst_pins;
{
String s = zookeeper->get(zookeeper_path + "/pinned_part_uuids", &src_pins.stat);
src_pins.fromString(s);
}
{
String s = zookeeper->get(to + "/pinned_part_uuids", &dst_pins.stat);
dst_pins.fromString(s);
}
if (src_pins.part_uuids.contains(part->uuid) || dst_pins.part_uuids.contains(part->uuid))
throw Exception(ErrorCodes::PART_IS_TEMPORARILY_LOCKED, "Part {} has it's uuid ({}) already pinned.", part_name, toString(part->uuid));
src_pins.part_uuids.insert(part->uuid);
dst_pins.part_uuids.insert(part->uuid);
PartMovesBetweenShardsOrchestrator::Entry part_move_entry;
part_move_entry.state = PartMovesBetweenShardsOrchestrator::EntryState::SYNC_SOURCE;
part_move_entry.create_time = std::time(nullptr);
part_move_entry.update_time = part_move_entry.create_time;
part_move_entry.task_uuid = UUIDHelpers::generateV4();
part_move_entry.part_name = part->name;
part_move_entry.part_uuid = part->uuid;
part_move_entry.to_shard = to;
Coordination::Requests ops;
ops.emplace_back(zkutil::makeCheckRequest(zookeeper_path + "/log", merge_pred.getVersion())); /// Make sure no new events were added to the log.
ops.emplace_back(zkutil::makeSetRequest(zookeeper_path + "/pinned_part_uuids", src_pins.toString(), src_pins.stat.version));
ops.emplace_back(zkutil::makeSetRequest(to + "/pinned_part_uuids", dst_pins.toString(), dst_pins.stat.version));
ops.emplace_back(zkutil::makeCreateRequest(
part_moves_between_shards_orchestrator.entries_znode_path + "/task-",
part_move_entry.toString(),
zkutil::CreateMode::PersistentSequential));
Coordination::Responses responses;
Coordination::Error rc = zookeeper->tryMulti(ops, responses);
zkutil::KeeperMultiException::check(rc, ops, responses);
String task_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*responses.back()).path_created;
LOG_DEBUG(log, "Created task for part movement between shards at {}", task_znode_path);
/// TODO(nv): Nice to have support for `replication_alter_partitions_sync`.
/// For now use the system.part_moves_between_shards table for status.
}
CancellationCode StorageReplicatedMergeTree::killPartMoveToShard(const UUID & task_uuid)
{
return part_moves_between_shards_orchestrator.killPartMoveToShard(task_uuid);
}
void StorageReplicatedMergeTree::getCommitPartOps(
Coordination::Requests & ops,
MutableDataPartPtr & part,
const String & block_id_path) const
{
const String & part_name = part->name;
const auto storage_settings_ptr = getSettings();
if (!block_id_path.empty())
{
/// Make final duplicate check and commit block_id
ops.emplace_back(
zkutil::makeCreateRequest(
block_id_path,
part_name, /// We will be able to know original part number for duplicate blocks, if we want.
zkutil::CreateMode::Persistent));
}
/// Information about the part, in the replica
if (storage_settings_ptr->use_minimalistic_part_header_in_zookeeper)
{
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(replica_path) / "parts" / part->name,
ReplicatedMergeTreePartHeader::fromColumnsAndChecksums(part->getColumns(), part->checksums).toString(),
zkutil::CreateMode::Persistent));
}
else
{
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(replica_path) / "parts" / part->name,
"",
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(replica_path) / "parts" / part->name / "columns",
part->getColumns().toString(),
zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeCreateRequest(
fs::path(replica_path) / "parts" / part->name / "checksums",
getChecksumsForZooKeeper(part->checksums),
zkutil::CreateMode::Persistent));
}
}
ReplicatedMergeTreeAddress StorageReplicatedMergeTree::getReplicatedMergeTreeAddress() const
{
auto host_port = getContext()->getInterserverIOAddress();
auto table_id = getStorageID();
ReplicatedMergeTreeAddress res;
res.host = host_port.first;
res.replication_port = host_port.second;
res.queries_port = getContext()->getTCPPort();
res.database = table_id.database_name;
res.table = table_id.table_name;
res.scheme = getContext()->getInterserverScheme();
return res;
}
ActionLock StorageReplicatedMergeTree::getActionLock(StorageActionBlockType action_type)
{
if (action_type == ActionLocks::PartsMerge)
return merger_mutator.merges_blocker.cancel();
if (action_type == ActionLocks::PartsTTLMerge)
return merger_mutator.ttl_merges_blocker.cancel();
if (action_type == ActionLocks::PartsFetch)
return fetcher.blocker.cancel();
if (action_type == ActionLocks::PartsSend)
{
auto data_parts_exchange_ptr = std::atomic_load(&data_parts_exchange_endpoint);
return data_parts_exchange_ptr ? data_parts_exchange_ptr->blocker.cancel() : ActionLock();
}
if (action_type == ActionLocks::ReplicationQueue)
return queue.actions_blocker.cancel();
if (action_type == ActionLocks::PartsMove)
return parts_mover.moves_blocker.cancel();
return {};
}
void StorageReplicatedMergeTree::onActionLockRemove(StorageActionBlockType action_type)
{
if (action_type == ActionLocks::PartsMerge || action_type == ActionLocks::PartsTTLMerge
|| action_type == ActionLocks::PartsFetch || action_type == ActionLocks::PartsSend
|| action_type == ActionLocks::ReplicationQueue)
background_operations_assignee.trigger();
else if (action_type == ActionLocks::PartsMove)
background_moves_assignee.trigger();
}
bool StorageReplicatedMergeTree::waitForShrinkingQueueSize(size_t queue_size, UInt64 max_wait_milliseconds)
{
Stopwatch watch;
/// Let's fetch new log entries firstly
queue.pullLogsToQueue(getZooKeeperAndAssertNotReadonly(), {}, ReplicatedMergeTreeQueue::SYNC);
/// This is significant, because the execution of this task could be delayed at BackgroundPool.
/// And we force it to be executed.
background_operations_assignee.trigger();
Poco::Event target_size_event;
auto callback = [&target_size_event, queue_size] (size_t new_queue_size)
{
if (new_queue_size <= queue_size)
target_size_event.set();
};
const auto handler = queue.addSubscriber(std::move(callback));
while (!target_size_event.tryWait(50))
{
if (max_wait_milliseconds && watch.elapsedMilliseconds() > max_wait_milliseconds)
return false;
if (partial_shutdown_called)
throw Exception("Shutdown is called for table", ErrorCodes::ABORTED);
}
return true;
}
bool StorageReplicatedMergeTree::dropPartImpl(
zkutil::ZooKeeperPtr & zookeeper, String part_name, LogEntry & entry, bool detach, bool throw_if_noop)
{
LOG_TRACE(log, "Will try to insert a log entry to DROP_RANGE for part {}", part_name);
auto part_info = MergeTreePartInfo::fromPartName(part_name, format_version);
while (true)
{
ReplicatedMergeTreeMergePredicate merge_pred = queue.getMergePredicate(zookeeper);
auto part = getPartIfExists(part_info, {MergeTreeDataPartState::Active});
if (!part)
{
if (throw_if_noop)
throw Exception("Part " + part_name + " not found locally, won't try to drop it.", ErrorCodes::NO_SUCH_DATA_PART);
return false;
}
if (merge_pred.hasDropRange(part->info))
{
if (throw_if_noop)
throw Exception("Already has DROP RANGE for part " + part_name + " in queue.", ErrorCodes::PART_IS_TEMPORARILY_LOCKED);
return false;
}
/// There isn't a lot we can do otherwise. Can't cancel merges because it is possible that a replica already
/// finished the merge.
if (partIsAssignedToBackgroundOperation(part))
{
if (throw_if_noop)
throw Exception("Part " + part_name
+ " is currently participating in a background operation (mutation/merge)"
+ ", try again later", ErrorCodes::PART_IS_TEMPORARILY_LOCKED);
return false;
}
if (partIsLastQuorumPart(part->info))
{
if (throw_if_noop)
throw Exception("Part " + part_name + " is last inserted part with quorum in partition. Cannot drop",
ErrorCodes::NOT_IMPLEMENTED);
return false;
}
if (partIsInsertingWithParallelQuorum(part->info))
{
if (throw_if_noop)
throw Exception("Part " + part_name + " is inserting with parallel quorum. Cannot drop",
ErrorCodes::NOT_IMPLEMENTED);
return false;
}
Coordination::Requests ops;
getClearBlocksInPartitionOps(ops, *zookeeper, part_info.partition_id, part_info.min_block, part_info.max_block);
size_t clear_block_ops_size = ops.size();
/// If `part_name` is result of a recent merge and source parts are still available then
/// DROP_RANGE with detach will move this part together with source parts to `detached/` dir.
entry.type = LogEntry::DROP_RANGE;
entry.source_replica = replica_name;
/// We don't set fake drop level (999999999) for the single part DROP_RANGE.
/// First of all we don't guarantee anything other than the part will not be
/// active after DROP PART, but covering part (without data of dropped part) can exist.
/// If we add part with 9999999 level than we can break invariant in virtual_parts of
/// the queue.
entry.new_part_name = getPartNamePossiblyFake(format_version, part->info);
entry.detach = detach;
entry.create_time = time(nullptr);
ops.emplace_back(zkutil::makeCheckRequest(fs::path(zookeeper_path) / "log", merge_pred.getVersion())); /// Make sure no new events were added to the log.
ops.emplace_back(zkutil::makeCreateRequest(fs::path(zookeeper_path) / "log/log-", entry.toString(), zkutil::CreateMode::PersistentSequential));
/// Just update version, because merges assignment relies on it
ops.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "log", "", -1));
Coordination::Responses responses;
Coordination::Error rc = zookeeper->tryMulti(ops, responses);
if (rc == Coordination::Error::ZBADVERSION)
{
LOG_TRACE(log, "A new log entry appeared while trying to commit DROP RANGE. Retry.");
continue;
}
else if (rc == Coordination::Error::ZNONODE)
{
LOG_TRACE(log, "Other replica already removing same part {} or part deduplication node was removed by background thread. Retry.", part_name);
continue;
}
else
zkutil::KeeperMultiException::check(rc, ops, responses);
String log_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*responses[clear_block_ops_size + 1]).path_created;
entry.znode_name = log_znode_path.substr(log_znode_path.find_last_of('/') + 1);
return true;
}
}
bool StorageReplicatedMergeTree::dropAllPartsInPartition(
zkutil::ZooKeeper & zookeeper, String & partition_id, LogEntry & entry, ContextPtr query_context, bool detach)
{
/// Retry if alter_partition_version changes
for (size_t retry = 0; retry < 1000; ++retry)
{
String alter_partition_version_path = zookeeper_path + "/alter_partition_version";
Coordination::Stat alter_partition_version_stat;
zookeeper.get(alter_partition_version_path, &alter_partition_version_stat);
MergeTreePartInfo drop_range_info;
/// It would prevent other replicas from assigning merges which intersect locked block number.
std::optional<EphemeralLockInZooKeeper> delimiting_block_lock;
if (!getFakePartCoveringAllPartsInPartition(partition_id, drop_range_info, delimiting_block_lock))
{
LOG_INFO(log, "Will not drop partition {}, it is empty.", partition_id);
return false;
}
clearBlocksInPartition(zookeeper, partition_id, drop_range_info.min_block, drop_range_info.max_block);
String drop_range_fake_part_name = getPartNamePossiblyFake(format_version, drop_range_info);
LOG_DEBUG(log, "Disabled merges covered by range {}", drop_range_fake_part_name);
/// Finally, having achieved the necessary invariants, you can put an entry in the log.
entry.type = LogEntry::DROP_RANGE;
entry.source_replica = replica_name;
entry.new_part_name = drop_range_fake_part_name;
entry.detach = detach;
entry.create_time = time(nullptr);
Coordination::Requests ops;
ops.emplace_back(zkutil::makeCreateRequest(fs::path(zookeeper_path) / "log/log-", entry.toString(),
zkutil::CreateMode::PersistentSequential));
/// Check and update version to avoid race with REPLACE_RANGE.
/// Otherwise new parts covered by drop_range_info may appear after execution of current DROP_RANGE entry
/// as a result of execution of concurrently created REPLACE_RANGE entry.
ops.emplace_back(zkutil::makeSetRequest(alter_partition_version_path, "", alter_partition_version_stat.version));
/// Just update version, because merges assignment relies on it
ops.emplace_back(zkutil::makeSetRequest(fs::path(zookeeper_path) / "log", "", -1));
delimiting_block_lock->getUnlockOps(ops);
if (auto txn = query_context->getZooKeeperMetadataTransaction())
txn->moveOpsTo(ops);
Coordination::Responses responses;
Coordination::Error code = zookeeper.tryMulti(ops, responses);
if (code == Coordination::Error::ZOK)
delimiting_block_lock->assumeUnlocked();
else if (code == Coordination::Error::ZBADVERSION)
{
/// Cannot retry automatically, because some zookeeper ops were lost on the first attempt. Will retry on DDLWorker-level.
if (query_context->getZooKeeperMetadataTransaction())
throw Exception(
"Cannot execute alter, because alter partition version was suddenly changed due to concurrent alter",
ErrorCodes::CANNOT_ASSIGN_ALTER);
continue;
}
else
zkutil::KeeperMultiException::check(code, ops, responses);
String log_znode_path = dynamic_cast<const Coordination::CreateResponse &>(*responses.front()).path_created;
entry.znode_name = log_znode_path.substr(log_znode_path.find_last_of('/') + 1);
getContext()->getMergeList().cancelInPartition(getStorageID(), partition_id, drop_range_info.max_block);
return true;
}
throw Exception(ErrorCodes::CANNOT_ASSIGN_ALTER,
"Cannot assign ALTER PARTITION because another ALTER PARTITION query was concurrently executed");
}
CheckResults StorageReplicatedMergeTree::checkData(const ASTPtr & query, ContextPtr local_context)
{
CheckResults results;
DataPartsVector data_parts;
if (const auto & check_query = query->as<ASTCheckQuery &>(); check_query.partition)
{
String partition_id = getPartitionIDFromQuery(check_query.partition, local_context);
data_parts = getDataPartsVectorInPartition(MergeTreeDataPartState::Active, partition_id);
}
else
data_parts = getDataPartsVector();
for (auto & part : data_parts)
{
try
{
results.push_back(part_check_thread.checkPart(part->name));
}
catch (const Exception & ex)
{
results.emplace_back(part->name, false, "Check of part finished with error: '" + ex.message() + "'");
}
}
return results;
}
void StorageReplicatedMergeTree::checkBrokenDisks()
{
auto disks = getStoragePolicy()->getDisks();
std::unique_ptr<DataPartsVector> parts;
for (auto disk_it = disks.rbegin(); disk_it != disks.rend(); ++disk_it)
{
auto disk_ptr = *disk_it;
if (disk_ptr->isBroken())
{
{
std::unique_lock lock(last_broken_disks_mutex);
if (!last_broken_disks.insert(disk_ptr->getName()).second)
continue;
}
LOG_INFO(log, "Scanning parts to recover on broken disk {} with path {}", disk_ptr->getName(), disk_ptr->getPath());
if (!parts)
parts = std::make_unique<DataPartsVector>(getDataPartsVector());
for (auto & part : *parts)
{
if (part->volume && part->volume->getDisk()->getName() == disk_ptr->getName())
broken_part_callback(part->name);
}
continue;
}
else
{
{
std::unique_lock lock(last_broken_disks_mutex);
if (last_broken_disks.erase(disk_ptr->getName()) > 0)
LOG_INFO(
log,
"Disk {} with path {} is recovered. Exclude it from last_broken_disks",
disk_ptr->getName(),
disk_ptr->getPath());
}
}
}
}
bool StorageReplicatedMergeTree::canUseAdaptiveGranularity() const
{
const auto storage_settings_ptr = getSettings();
return storage_settings_ptr->index_granularity_bytes != 0 &&
(storage_settings_ptr->enable_mixed_granularity_parts ||
(!has_non_adaptive_index_granularity_parts && !other_replicas_fixed_granularity));
}
MutationCommands StorageReplicatedMergeTree::getFirstAlterMutationCommandsForPart(const DataPartPtr & part) const
{
return queue.getFirstAlterMutationCommandsForPart(part);
}
void StorageReplicatedMergeTree::startBackgroundMovesIfNeeded()
{
if (areBackgroundMovesNeeded())
background_moves_assignee.start();
}
std::unique_ptr<MergeTreeSettings> StorageReplicatedMergeTree::getDefaultSettings() const
{
return std::make_unique<MergeTreeSettings>(getContext()->getReplicatedMergeTreeSettings());
}
String StorageReplicatedMergeTree::getTableSharedID() const
{
return toString(table_shared_id);
}
void StorageReplicatedMergeTree::createTableSharedID()
{
if (table_shared_id != UUIDHelpers::Nil)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Table shared id already initialized");
zkutil::ZooKeeperPtr zookeeper = getZooKeeper();
String zookeeper_table_id_path = fs::path(zookeeper_path) / "table_shared_id";
String id;
if (!zookeeper->tryGet(zookeeper_table_id_path, id))
{
UUID table_id_candidate;
auto local_storage_id = getStorageID();
if (local_storage_id.uuid != UUIDHelpers::Nil)
table_id_candidate = local_storage_id.uuid;
else
table_id_candidate = UUIDHelpers::generateV4();
id = toString(table_id_candidate);
auto code = zookeeper->tryCreate(zookeeper_table_id_path, id, zkutil::CreateMode::Persistent);
if (code == Coordination::Error::ZNODEEXISTS)
{ /// Other replica create node early
id = zookeeper->get(zookeeper_table_id_path);
}
else if (code != Coordination::Error::ZOK)
{
throw zkutil::KeeperException(code, zookeeper_table_id_path);
}
}
table_shared_id = parseFromString<UUID>(id);
}
void StorageReplicatedMergeTree::lockSharedDataTemporary(const String & part_name, const String & part_id, const DiskPtr & disk) const
{
if (!disk || !disk->supportZeroCopyReplication())
return;
zkutil::ZooKeeperPtr zookeeper = tryGetZooKeeper();
if (!zookeeper)
return;
String id = part_id;
boost::replace_all(id, "/", "_");
Strings zc_zookeeper_paths = getZeroCopyPartPath(*getSettings(), disk->getType(), getTableSharedID(),
part_name, zookeeper_path);
for (const auto & zc_zookeeper_path : zc_zookeeper_paths)
{
String zookeeper_node = fs::path(zc_zookeeper_path) / id / replica_name;
LOG_TRACE(log, "Set zookeeper temporary ephemeral lock {}", zookeeper_node);
createZeroCopyLockNode(zookeeper, zookeeper_node, zkutil::CreateMode::Ephemeral, false);
}
}
void StorageReplicatedMergeTree::lockSharedData(const IMergeTreeDataPart & part, bool replace_existing_lock) const
{
if (!part.volume || !part.isStoredOnDisk())
return;
DiskPtr disk = part.volume->getDisk();
if (!disk || !disk->supportZeroCopyReplication())
return;
zkutil::ZooKeeperPtr zookeeper = tryGetZooKeeper();
if (!zookeeper)
return;
String id = part.getUniqueId();
boost::replace_all(id, "/", "_");
Strings zc_zookeeper_paths = getZeroCopyPartPath(*getSettings(), disk->getType(), getTableSharedID(),
part.name, zookeeper_path);
for (const auto & zc_zookeeper_path : zc_zookeeper_paths)
{
String zookeeper_node = fs::path(zc_zookeeper_path) / id / replica_name;
LOG_TRACE(log, "Set zookeeper persistent lock {}", zookeeper_node);
createZeroCopyLockNode(zookeeper, zookeeper_node, zkutil::CreateMode::Persistent, replace_existing_lock);
}
}
bool StorageReplicatedMergeTree::unlockSharedData(const IMergeTreeDataPart & part) const
{
return unlockSharedData(part, part.name);
}
bool StorageReplicatedMergeTree::unlockSharedData(const IMergeTreeDataPart & part, const String & name) const
{
if (!part.volume || !part.isStoredOnDisk())
return true;
DiskPtr disk = part.volume->getDisk();
if (!disk || !disk->supportZeroCopyReplication())
return true;
/// If part is temporary refcount file may be absent
auto ref_count_path = fs::path(part.getFullRelativePath()) / IMergeTreeDataPart::FILE_FOR_REFERENCES_CHECK;
if (disk->exists(ref_count_path))
{
auto ref_count = disk->getRefCount(ref_count_path);
if (ref_count > 0) /// Keep part shard info for frozen backups
return false;
}
else
{
/// Temporary part with some absent file cannot be locked in shared mode
return true;
}
return unlockSharedDataByID(part.getUniqueId(), getTableSharedID(), name, replica_name, disk, getZooKeeper(), *getSettings(), log,
zookeeper_path);
}
bool StorageReplicatedMergeTree::unlockSharedDataByID(String part_id, const String & table_uuid, const String & part_name,
const String & replica_name_, DiskPtr disk, zkutil::ZooKeeperPtr zookeeper_ptr, const MergeTreeSettings & settings,
Poco::Logger * logger, const String & zookeeper_path_old)
{
boost::replace_all(part_id, "/", "_");
Strings zc_zookeeper_paths = getZeroCopyPartPath(settings, disk->getType(), table_uuid, part_name, zookeeper_path_old);
bool part_has_no_more_locks = true;
for (const auto & zc_zookeeper_path : zc_zookeeper_paths)
{
String zookeeper_part_uniq_node = fs::path(zc_zookeeper_path) / part_id;
/// Delete our replica node for part from zookeeper (we are not interested in it anymore)
String zookeeper_part_replica_node = fs::path(zookeeper_part_uniq_node) / replica_name_;
LOG_TRACE(logger, "Remove zookeeper lock {}", zookeeper_part_replica_node);
zookeeper_ptr->tryRemove(zookeeper_part_replica_node);
/// Check, maybe we were the last replica and can remove part forever
Strings children;
zookeeper_ptr->tryGetChildren(zookeeper_part_uniq_node, children);
if (!children.empty())
{
LOG_TRACE(logger, "Found zookeper locks for {}", zookeeper_part_uniq_node);
part_has_no_more_locks = false;
continue;
}
auto error_code = zookeeper_ptr->tryRemove(zookeeper_part_uniq_node);
LOG_TRACE(logger, "Remove parent zookeeper lock {} : {}", zookeeper_part_uniq_node, error_code != Coordination::Error::ZNOTEMPTY);
/// Even when we have lock with same part name, but with different uniq, we can remove files on S3
children.clear();
String zookeeper_part_node = fs::path(zookeeper_part_uniq_node).parent_path();
zookeeper_ptr->tryGetChildren(zookeeper_part_node, children);
if (children.empty())
{
/// Cleanup after last uniq removing
error_code = zookeeper_ptr->tryRemove(zookeeper_part_node);
LOG_TRACE(logger, "Remove parent zookeeper lock {} : {}", zookeeper_part_node, error_code != Coordination::Error::ZNOTEMPTY);
}
else
{
LOG_TRACE(logger, "Can't remove parent zookeeper lock {} : {}", zookeeper_part_node, children.size());
for (auto & c : children)
{
LOG_TRACE(logger, "Child node {}", c);
}
}
}
return part_has_no_more_locks;
}
bool StorageReplicatedMergeTree::tryToFetchIfShared(
const IMergeTreeDataPart & part,
const DiskPtr & disk,
const String & path)
{
const auto settings = getSettings();
auto disk_type = disk->getType();
if (!(disk->supportZeroCopyReplication() && settings->allow_remote_fs_zero_copy_replication))
return false;
String replica = getSharedDataReplica(part, disk_type);
/// We can't fetch part when none replicas have this part on a same type remote disk
if (replica.empty())
return false;
return executeFetchShared(replica, part.name, disk, path);
}
String StorageReplicatedMergeTree::getSharedDataReplica(
const IMergeTreeDataPart & part, DiskType disk_type) const
{
String best_replica;
zkutil::ZooKeeperPtr zookeeper = tryGetZooKeeper();
if (!zookeeper)
return "";
Strings zc_zookeeper_paths = getZeroCopyPartPath(*getSettings(), disk_type, getTableSharedID(), part.name,
zookeeper_path);
std::set<String> replicas;
for (const auto & zc_zookeeper_path : zc_zookeeper_paths)
{
Strings ids;
zookeeper->tryGetChildren(zc_zookeeper_path, ids);
for (const auto & id : ids)
{
String zookeeper_part_uniq_node = fs::path(zc_zookeeper_path) / id;
Strings id_replicas;
zookeeper->tryGetChildren(zookeeper_part_uniq_node, id_replicas);
LOG_TRACE(log, "Found zookeper replicas for {}: {}", zookeeper_part_uniq_node, id_replicas.size());
replicas.insert(id_replicas.begin(), id_replicas.end());
}
}
LOG_TRACE(log, "Found zookeper replicas for part {}: {}", part.name, replicas.size());
Strings active_replicas;
/// TODO: Move best replica choose in common method (here is the same code as in StorageReplicatedMergeTree::fetchPartition)
/// Leave only active replicas.
active_replicas.reserve(replicas.size());
for (const String & replica : replicas)
if ((replica != replica_name) && (zookeeper->exists(fs::path(zookeeper_path) / "replicas" / replica / "is_active")))
active_replicas.push_back(replica);
LOG_TRACE(log, "Found zookeper active replicas for part {}: {}", part.name, active_replicas.size());
if (active_replicas.empty())
return "";
/** You must select the best (most relevant) replica.
* This is a replica with the maximum `log_pointer`, then with the minimum `queue` size.
* NOTE This is not exactly the best criteria. It does not make sense to download old partitions,
* and it would be nice to be able to choose the replica closest by network.
* NOTE Of course, there are data races here. You can solve it by retrying.
*/
Int64 max_log_pointer = -1;
UInt64 min_queue_size = std::numeric_limits<UInt64>::max();
for (const String & replica : active_replicas)
{
String current_replica_path = fs::path(zookeeper_path) / "replicas" / replica;
String log_pointer_str = zookeeper->get(fs::path(current_replica_path) / "log_pointer");
Int64 log_pointer = log_pointer_str.empty() ? 0 : parse<UInt64>(log_pointer_str);
Coordination::Stat stat;
zookeeper->get(fs::path(current_replica_path) / "queue", &stat);
size_t queue_size = stat.numChildren;
if (log_pointer > max_log_pointer
|| (log_pointer == max_log_pointer && queue_size < min_queue_size))
{
max_log_pointer = log_pointer;
min_queue_size = queue_size;
best_replica = replica;
}
}
return best_replica;
}
Strings StorageReplicatedMergeTree::getZeroCopyPartPath(const MergeTreeSettings & settings, DiskType disk_type, const String & table_uuid,
const String & part_name, const String & zookeeper_path_old)
{
Strings res;
String zero_copy = fmt::format("zero_copy_{}", toString(disk_type));
String new_path = fs::path(settings.remote_fs_zero_copy_zookeeper_path.toString()) / zero_copy / table_uuid / part_name;
res.push_back(new_path);
if (settings.remote_fs_zero_copy_path_compatible_mode && !zookeeper_path_old.empty())
{ /// Compatibility mode for cluster with old and new versions
String old_path = fs::path(zookeeper_path_old) / zero_copy / "shared" / part_name;
res.push_back(old_path);
}
return res;
}
bool StorageReplicatedMergeTree::checkZeroCopyLockExists(const String & part_name, const DiskPtr & disk)
{
auto path = getZeroCopyPartPath(part_name, disk);
if (path)
{
/// FIXME
auto lock_path = fs::path(*path) / "part_exclusive_lock";
if (getZooKeeper()->exists(lock_path))
{
return true;
}
}
return false;
}
std::optional<String> StorageReplicatedMergeTree::getZeroCopyPartPath(const String & part_name, const DiskPtr & disk)
{
if (!disk || !disk->supportZeroCopyReplication())
return std::nullopt;
return getZeroCopyPartPath(*getSettings(), disk->getType(), getTableSharedID(), part_name, zookeeper_path)[0];
}
std::optional<ZeroCopyLock> StorageReplicatedMergeTree::tryCreateZeroCopyExclusiveLock(const String & part_name, const DiskPtr & disk)
{
if (!disk || !disk->supportZeroCopyReplication())
return std::nullopt;
zkutil::ZooKeeperPtr zookeeper = tryGetZooKeeper();
if (!zookeeper)
return std::nullopt;
String zc_zookeeper_path = *getZeroCopyPartPath(part_name, disk);
/// Just recursively create ancestors for lock
zookeeper->createAncestors(zc_zookeeper_path);
zookeeper->createIfNotExists(zc_zookeeper_path, "");
/// Create actual lock
ZeroCopyLock lock(zookeeper, zc_zookeeper_path);
if (lock.lock->tryLock())
return lock;
else
return std::nullopt;
}
String StorageReplicatedMergeTree::findReplicaHavingPart(
const String & part_name, const String & zookeeper_path_, zkutil::ZooKeeper::Ptr zookeeper_ptr)
{
Strings replicas = zookeeper_ptr->getChildren(fs::path(zookeeper_path_) / "replicas");
/// Select replicas in uniformly random order.
std::shuffle(replicas.begin(), replicas.end(), thread_local_rng);
for (const String & replica : replicas)
{
if (zookeeper_ptr->exists(fs::path(zookeeper_path_) / "replicas" / replica / "parts" / part_name)
&& zookeeper_ptr->exists(fs::path(zookeeper_path_) / "replicas" / replica / "is_active"))
return fs::path(zookeeper_path_) / "replicas" / replica;
}
return {};
}
bool StorageReplicatedMergeTree::checkIfDetachedPartExists(const String & part_name)
{
fs::directory_iterator dir_end;
for (const std::string & path : getDataPaths())
for (fs::directory_iterator dir_it{fs::path(path) / "detached/"}; dir_it != dir_end; ++dir_it)
if (dir_it->path().filename().string() == part_name)
return true;
return false;
}
bool StorageReplicatedMergeTree::checkIfDetachedPartitionExists(const String & partition_name)
{
fs::directory_iterator dir_end;
for (const std::string & path : getDataPaths())
{
for (fs::directory_iterator dir_it{fs::path(path) / "detached/"}; dir_it != dir_end; ++dir_it)
{
const String file_name = dir_it->path().filename().string();
auto part_info = MergeTreePartInfo::tryParsePartName(file_name, format_version);
if (part_info && part_info->partition_id == partition_name)
return true;
}
}
return false;
}
bool StorageReplicatedMergeTree::createEmptyPartInsteadOfLost(zkutil::ZooKeeperPtr zookeeper, const String & lost_part_name)
{
LOG_INFO(log, "Going to replace lost part {} with empty part", lost_part_name);
auto metadata_snapshot = getInMemoryMetadataPtr();
auto settings = getSettings();
constexpr static auto TMP_PREFIX = "tmp_empty_";
auto new_part_info = MergeTreePartInfo::fromPartName(lost_part_name, format_version);
auto block = metadata_snapshot->getSampleBlock();
DB::IMergeTreeDataPart::TTLInfos move_ttl_infos;
NamesAndTypesList columns = metadata_snapshot->getColumns().getAllPhysical().filter(block.getNames());
ReservationPtr reservation = reserveSpacePreferringTTLRules(metadata_snapshot, 0, move_ttl_infos, time(nullptr), 0, true);
VolumePtr volume = getStoragePolicy()->getVolume(0);
auto minmax_idx = std::make_shared<IMergeTreeDataPart::MinMaxIndex>();
minmax_idx->update(block, getMinMaxColumnsNames(metadata_snapshot->getPartitionKey()));
auto new_data_part = createPart(
lost_part_name,
choosePartType(0, block.rows()),
new_part_info,
createVolumeFromReservation(reservation, volume),
TMP_PREFIX + lost_part_name);
if (settings->assign_part_uuids)
new_data_part->uuid = UUIDHelpers::generateV4();
new_data_part->setColumns(columns);
new_data_part->rows_count = block.rows();
{
auto lock = lockParts();
auto parts_in_partition = getDataPartsPartitionRange(new_part_info.partition_id);
if (!parts_in_partition.empty())
{
new_data_part->partition = (*parts_in_partition.begin())->partition;
}
else if (auto parsed_partition = MergeTreePartition::tryParseValueFromID(
new_part_info.partition_id,
metadata_snapshot->getPartitionKey().sample_block))
{
new_data_part->partition = MergeTreePartition(*parsed_partition);
}
else
{
LOG_WARNING(log, "Empty part {} is not created instead of lost part because there are no parts in partition {} (it's empty), "
"resolve this manually using DROP/DETACH PARTITION.", lost_part_name, new_part_info.partition_id);
return false;
}
}
new_data_part->minmax_idx = std::move(minmax_idx);
new_data_part->is_temp = true;
SyncGuardPtr sync_guard;
if (new_data_part->isStoredOnDisk())
{
/// The name could be non-unique in case of stale files from previous runs.
String full_path = new_data_part->getFullRelativePath();
if (new_data_part->volume->getDisk()->exists(full_path))
{
LOG_WARNING(log, "Removing old temporary directory {}", fullPath(new_data_part->volume->getDisk(), full_path));
new_data_part->volume->getDisk()->removeRecursive(full_path);
}
const auto disk = new_data_part->volume->getDisk();
disk->createDirectories(full_path);
if (getSettings()->fsync_part_directory)
sync_guard = disk->getDirectorySyncGuard(full_path);
}
/// This effectively chooses minimal compression method:
/// either default lz4 or compression method with zero thresholds on absolute and relative part size.
auto compression_codec = getContext()->chooseCompressionCodec(0, 0);
const auto & index_factory = MergeTreeIndexFactory::instance();
MergedBlockOutputStream out(new_data_part, metadata_snapshot, columns,
index_factory.getMany(metadata_snapshot->getSecondaryIndices()), compression_codec);
bool sync_on_insert = settings->fsync_after_insert;
out.write(block);
/// TODO(ab): What projections should we add to the empty part? How can we make sure that it
/// won't block future merges? Perhaps we should also check part emptiness when selecting parts
/// to merge.
out.finalizePart(new_data_part, sync_on_insert);
try
{
MergeTreeData::Transaction transaction(*this);
auto replaced_parts = renameTempPartAndReplace(new_data_part, nullptr, &transaction);
if (!replaced_parts.empty())
{
Strings part_names;
for (const auto & part : replaced_parts)
part_names.emplace_back(part->name);
/// Why this exception is not a LOGICAL_ERROR? Because it's possible
/// to have some source parts for the lost part if replica currently
/// cloning from another replica, but source replica lost covering
/// part and finished MERGE_PARTS before clone. It's an extremely
/// rare case and it's unclear how to resolve it better. Eventually
/// source replica will replace lost part with empty part and we
/// will fetch this empty part instead of our source parts. This
/// will make replicas consistent, but some data will be lost.
throw Exception(ErrorCodes::INCORRECT_DATA, "Tried to create empty part {}, but it replaces existing parts {}.", lost_part_name, fmt::join(part_names, ", "));
}
while (true)
{
Coordination::Requests ops;
Coordination::Stat replicas_stat;
auto replicas_path = fs::path(zookeeper_path) / "replicas";
Strings replicas = zookeeper->getChildren(replicas_path, &replicas_stat);
/// In rare cases new replica can appear during check
ops.emplace_back(zkutil::makeCheckRequest(replicas_path, replicas_stat.version));
for (const String & replica : replicas)
{
String current_part_path = fs::path(zookeeper_path) / "replicas" / replica / "parts" / lost_part_name;
/// We must be sure that this part doesn't exist on other replicas
if (!zookeeper->exists(current_part_path))
{
ops.emplace_back(zkutil::makeCreateRequest(current_part_path, "", zkutil::CreateMode::Persistent));
ops.emplace_back(zkutil::makeRemoveRequest(current_part_path, -1));
}
else
{
throw Exception(ErrorCodes::DUPLICATE_DATA_PART, "Part {} already exists on replica {} on path {}", lost_part_name, replica, current_part_path);
}
}
getCommitPartOps(ops, new_data_part);
Coordination::Responses responses;
if (auto code = zookeeper->tryMulti(ops, responses); code == Coordination::Error::ZOK)
{
transaction.commit();
break;
}
else if (code == Coordination::Error::ZBADVERSION)
{
LOG_INFO(log, "Looks like new replica appearead while creating new empty part, will retry");
}
else
{
zkutil::KeeperMultiException::check(code, ops, responses);
}
}
}
catch (const Exception & ex)
{
LOG_WARNING(log, "Cannot commit empty part {} with error {}", lost_part_name, ex.displayText());
return false;
}
LOG_INFO(log, "Created empty part {} instead of lost part", lost_part_name);
return true;
}
void StorageReplicatedMergeTree::createZeroCopyLockNode(const zkutil::ZooKeeperPtr & zookeeper, const String & zookeeper_node, int32_t mode, bool replace_existing_lock)
{
/// In rare case other replica can remove path between createAncestors and createIfNotExists
/// So we make up to 5 attempts
for (int attempts = 5; attempts > 0; --attempts)
{
try
{
/// Ephemeral locks can be created only when we fetch shared data.
/// So it never require to create ancestors. If we create them
/// race condition with source replica drop is possible.
if (mode == zkutil::CreateMode::Persistent)
zookeeper->createAncestors(zookeeper_node);
if (replace_existing_lock && zookeeper->exists(zookeeper_node))
{
Coordination::Requests ops;
ops.emplace_back(zkutil::makeRemoveRequest(zookeeper_node, -1));
ops.emplace_back(zkutil::makeCreateRequest(zookeeper_node, "", mode));
Coordination::Responses responses;
auto error = zookeeper->tryMulti(ops, responses);
if (error == Coordination::Error::ZOK)
break;
}
else
{
auto error = zookeeper->tryCreate(zookeeper_node, "", mode);
if (error == Coordination::Error::ZOK || error == Coordination::Error::ZNODEEXISTS)
break;
}
}
catch (const zkutil::KeeperException & e)
{
if (e.code == Coordination::Error::ZNONODE)
continue;
throw;
}
}
}
namespace
{
/// Special metadata used during freeze table. Required for zero-copy
/// replication.
struct FreezeMetaData
{
public:
void fill(const StorageReplicatedMergeTree & storage)
{
is_replicated = storage.supportsReplication();
is_remote = storage.isRemote();
replica_name = storage.getReplicaName();
zookeeper_name = storage.getZooKeeperName();
table_shared_id = storage.getTableSharedID();
}
void save(DiskPtr data_disk, const String & path) const
{
auto metadata_disk = data_disk->getMetadataDiskIfExistsOrSelf();
auto file_path = getFileName(path);
auto buffer = metadata_disk->writeFile(file_path, DBMS_DEFAULT_BUFFER_SIZE, WriteMode::Rewrite);
writeIntText(version, *buffer);
buffer->write("\n", 1);
writeBoolText(is_replicated, *buffer);
buffer->write("\n", 1);
writeBoolText(is_remote, *buffer);
buffer->write("\n", 1);
writeString(replica_name, *buffer);
buffer->write("\n", 1);
writeString(zookeeper_name, *buffer);
buffer->write("\n", 1);
writeString(table_shared_id, *buffer);
buffer->write("\n", 1);
}
bool load(DiskPtr data_disk, const String & path)
{
auto metadata_disk = data_disk->getMetadataDiskIfExistsOrSelf();
auto file_path = getFileName(path);
if (!metadata_disk->exists(file_path))
return false;
auto buffer = metadata_disk->readFile(file_path, ReadSettings(), {});
readIntText(version, *buffer);
if (version != 1)
{
LOG_ERROR(&Poco::Logger::get("FreezeMetaData"), "Unknown freezed metadata version: {}", version);
return false;
}
DB::assertChar('\n', *buffer);
readBoolText(is_replicated, *buffer);
DB::assertChar('\n', *buffer);
readBoolText(is_remote, *buffer);
DB::assertChar('\n', *buffer);
readString(replica_name, *buffer);
DB::assertChar('\n', *buffer);
readString(zookeeper_name, *buffer);
DB::assertChar('\n', *buffer);
readString(table_shared_id, *buffer);
DB::assertChar('\n', *buffer);
return true;
}
static void clean(DiskPtr data_disk, const String & path)
{
auto metadata_disk = data_disk->getMetadataDiskIfExistsOrSelf();
metadata_disk->removeFileIfExists(getFileName(path));
}
private:
static String getFileName(const String & path)
{
return fs::path(path) / "frozen_metadata.txt";
}
public:
int version = 1;
bool is_replicated;
bool is_remote;
String replica_name;
String zookeeper_name;
String table_shared_id;
};
}
bool StorageReplicatedMergeTree::removeDetachedPart(DiskPtr disk, const String & path, const String & part_name, bool is_freezed)
{
if (disk->supportZeroCopyReplication())
{
if (is_freezed)
{
FreezeMetaData meta;
if (meta.load(disk, path))
{
FreezeMetaData::clean(disk, path);
return removeSharedDetachedPart(disk, path, part_name, meta.table_shared_id, meta.zookeeper_name, meta.replica_name, "");
}
}
else
{
String table_id = getTableSharedID();
return removeSharedDetachedPart(disk, path, part_name, table_id, zookeeper_name, replica_name, zookeeper_path);
}
}
disk->removeRecursive(path);
return false;
}
bool StorageReplicatedMergeTree::removeSharedDetachedPart(DiskPtr disk, const String & path, const String & part_name, const String & table_uuid,
const String &, const String & detached_replica_name, const String & detached_zookeeper_path)
{
bool keep_shared = false;
zkutil::ZooKeeperPtr zookeeper = getZooKeeper();
fs::path checksums = fs::path(path) / IMergeTreeDataPart::FILE_FOR_REFERENCES_CHECK;
if (disk->exists(checksums))
{
if (disk->getRefCount(checksums) == 0)
{
String id = disk->getUniqueId(checksums);
keep_shared = !StorageReplicatedMergeTree::unlockSharedDataByID(id, table_uuid, part_name,
detached_replica_name, disk, zookeeper, getContext()->getReplicatedMergeTreeSettings(), log,
detached_zookeeper_path);
}
else
keep_shared = true;
}
disk->removeSharedRecursive(path, keep_shared);
return keep_shared;
}
void StorageReplicatedMergeTree::createAndStoreFreezeMetadata(DiskPtr disk, DataPartPtr, String backup_part_path) const
{
if (disk->supportZeroCopyReplication())
{
FreezeMetaData meta;
meta.fill(*this);
meta.save(disk, backup_part_path);
}
}
}