ClickHouse/dbms/Storages/Distributed/DistributedBlockOutputStream.cpp
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

629 lines
21 KiB
C++

#include <Storages/Distributed/DistributedBlockOutputStream.h>
#include <Storages/Distributed/DirectoryMonitor.h>
#include <Storages/StorageDistributed.h>
#include <Disks/DiskSpaceMonitor.h>
#include <Parsers/formatAST.h>
#include <Parsers/queryToString.h>
#include <IO/WriteBufferFromFile.h>
#include <Compression/CompressedWriteBuffer.h>
#include <IO/Operators.h>
#include <IO/WriteBufferFromString.h>
#include <DataStreams/NativeBlockOutputStream.h>
#include <DataStreams/RemoteBlockOutputStream.h>
#include <Interpreters/InterpreterInsertQuery.h>
#include <Interpreters/createBlockSelector.h>
#include <Interpreters/ExpressionActions.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeLowCardinality.h>
#include <Common/setThreadName.h>
#include <Common/ClickHouseRevision.h>
#include <Common/CurrentMetrics.h>
#include <Common/typeid_cast.h>
#include <Common/Exception.h>
#include <Common/ProfileEvents.h>
#include <Common/escapeForFileName.h>
#include <Common/CurrentThread.h>
#include <common/logger_useful.h>
#include <ext/range.h>
#include <ext/scope_guard.h>
#include <Poco/DirectoryIterator.h>
#include <future>
#include <condition_variable>
#include <mutex>
namespace CurrentMetrics
{
extern const Metric DistributedSend;
}
namespace ProfileEvents
{
extern const Event DistributedSyncInsertionTimeoutExceeded;
}
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int TIMEOUT_EXCEEDED;
extern const int TYPE_MISMATCH;
extern const int CANNOT_LINK;
}
DistributedBlockOutputStream::DistributedBlockOutputStream(
const Context & context_, StorageDistributed & storage_, const ASTPtr & query_ast_, const ClusterPtr & cluster_,
bool insert_sync_, UInt64 insert_timeout_)
: context(context_), storage(storage_), query_ast(query_ast_), query_string(queryToString(query_ast_)),
cluster(cluster_), insert_sync(insert_sync_),
insert_timeout(insert_timeout_), log(&Logger::get("DistributedBlockOutputStream"))
{
}
Block DistributedBlockOutputStream::getHeader() const
{
return storage.getSampleBlock();
}
void DistributedBlockOutputStream::writePrefix()
{
}
void DistributedBlockOutputStream::write(const Block & block)
{
Block ordinary_block{ block };
/* They are added by the AddingDefaultBlockOutputStream, and we will get
* different number of columns eventually */
for (const auto & col : storage.getColumns().getMaterialized())
{
if (ordinary_block.has(col.name))
{
ordinary_block.erase(col.name);
LOG_DEBUG(log, storage.getStorageID().getNameForLogs()
<< ": column " + col.name + " will be removed, "
<< "because it is MATERIALIZED");
}
}
if (insert_sync)
writeSync(ordinary_block);
else
writeAsync(ordinary_block);
}
void DistributedBlockOutputStream::writeAsync(const Block & block)
{
if (storage.getShardingKeyExpr() && (cluster->getShardsInfo().size() > 1))
return writeSplitAsync(block);
writeAsyncImpl(block);
++inserted_blocks;
}
std::string DistributedBlockOutputStream::getCurrentStateDescription()
{
std::stringstream buffer;
const auto & addresses = cluster->getShardsAddresses();
buffer << "Insertion status:\n";
for (auto & shard_jobs : per_shard_jobs)
for (JobReplica & job : shard_jobs.replicas_jobs)
{
buffer << "Wrote " << job.blocks_written << " blocks and " << job.rows_written << " rows"
<< " on shard " << job.shard_index << " replica " << job.replica_index
<< ", " << addresses[job.shard_index][job.replica_index].readableString();
/// Performance statistics
if (job.blocks_started > 0)
{
buffer << " (average " << job.elapsed_time_ms / job.blocks_started << " ms per block";
if (job.blocks_started > 1)
buffer << ", the slowest block " << job.max_elapsed_time_for_block_ms << " ms";
buffer << ")";
}
buffer << "\n";
}
return buffer.str();
}
void DistributedBlockOutputStream::initWritingJobs(const Block & first_block)
{
const auto & addresses_with_failovers = cluster->getShardsAddresses();
const auto & shards_info = cluster->getShardsInfo();
size_t num_shards = shards_info.size();
remote_jobs_count = 0;
local_jobs_count = 0;
per_shard_jobs.resize(shards_info.size());
for (size_t shard_index : ext::range(0, shards_info.size()))
{
const auto & shard_info = shards_info[shard_index];
auto & shard_jobs = per_shard_jobs[shard_index];
/// If hasInternalReplication, than prefer local replica
if (!shard_info.hasInternalReplication() || !shard_info.isLocal())
{
const auto & replicas = addresses_with_failovers[shard_index];
for (size_t replica_index : ext::range(0, replicas.size()))
{
if (!replicas[replica_index].is_local)
{
shard_jobs.replicas_jobs.emplace_back(shard_index, replica_index, false, first_block);
++remote_jobs_count;
if (shard_info.hasInternalReplication())
break;
}
}
}
if (shard_info.isLocal())
{
shard_jobs.replicas_jobs.emplace_back(shard_index, 0, true, first_block);
++local_jobs_count;
}
if (num_shards > 1)
shard_jobs.shard_current_block_permutation.reserve(first_block.rows());
}
}
void DistributedBlockOutputStream::waitForJobs()
{
pool->wait();
if (insert_timeout)
{
if (static_cast<UInt64>(watch.elapsedSeconds()) > insert_timeout)
{
ProfileEvents::increment(ProfileEvents::DistributedSyncInsertionTimeoutExceeded);
throw Exception("Synchronous distributed insert timeout exceeded.", ErrorCodes::TIMEOUT_EXCEEDED);
}
}
size_t jobs_count = remote_jobs_count + local_jobs_count;
size_t num_finished_jobs = finished_jobs_count;
if (num_finished_jobs < jobs_count)
LOG_WARNING(log, "Expected " << jobs_count << " writing jobs, but finished only " << num_finished_jobs);
}
ThreadPool::Job DistributedBlockOutputStream::runWritingJob(DistributedBlockOutputStream::JobReplica & job, const Block & current_block)
{
auto thread_group = CurrentThread::getGroup();
return [this, thread_group, &job, &current_block]()
{
if (thread_group)
CurrentThread::attachToIfDetached(thread_group);
setThreadName("DistrOutStrProc");
++job.blocks_started;
SCOPE_EXIT({
++finished_jobs_count;
UInt64 elapsed_time_for_block_ms = watch_current_block.elapsedMilliseconds();
job.elapsed_time_ms += elapsed_time_for_block_ms;
job.max_elapsed_time_for_block_ms = std::max(job.max_elapsed_time_for_block_ms, elapsed_time_for_block_ms);
});
const auto & shard_info = cluster->getShardsInfo()[job.shard_index];
size_t num_shards = cluster->getShardsInfo().size();
auto & shard_job = per_shard_jobs[job.shard_index];
const auto & addresses = cluster->getShardsAddresses();
/// Generate current shard block
if (num_shards > 1)
{
auto & shard_permutation = shard_job.shard_current_block_permutation;
size_t num_shard_rows = shard_permutation.size();
for (size_t j = 0; j < current_block.columns(); ++j)
{
auto & src_column = current_block.getByPosition(j).column;
auto & dst_column = job.current_shard_block.getByPosition(j).column;
/// Zero permutation size has special meaning in IColumn::permute
if (num_shard_rows)
dst_column = src_column->permute(shard_permutation, num_shard_rows);
else
dst_column = src_column->cloneEmpty();
}
}
const Block & shard_block = (num_shards > 1) ? job.current_shard_block : current_block;
if (!job.is_local_job)
{
if (!job.stream)
{
const Settings & settings = context.getSettingsRef();
auto timeouts = ConnectionTimeouts::getTCPTimeoutsWithFailover(settings);
if (shard_info.hasInternalReplication())
{
/// Skip replica_index in case of internal replication
if (shard_job.replicas_jobs.size() != 1)
throw Exception("There are several writing job for an automatically replicated shard", ErrorCodes::LOGICAL_ERROR);
/// TODO: it make sense to rewrite skip_unavailable_shards and max_parallel_replicas here
auto connections = shard_info.pool->getMany(timeouts, &settings, PoolMode::GET_ONE);
if (connections.empty() || connections.front().isNull())
throw Exception("Expected exactly one connection for shard " + toString(job.shard_index), ErrorCodes::LOGICAL_ERROR);
job.connection_entry = std::move(connections.front());
}
else
{
const auto & replica = addresses.at(job.shard_index).at(job.replica_index);
const ConnectionPoolPtr & connection_pool = shard_info.per_replica_pools.at(job.replica_index);
if (!connection_pool)
throw Exception("Connection pool for replica " + replica.readableString() + " does not exist", ErrorCodes::LOGICAL_ERROR);
job.connection_entry = connection_pool->get(timeouts, &settings);
if (job.connection_entry.isNull())
throw Exception("Got empty connection for replica" + replica.readableString(), ErrorCodes::LOGICAL_ERROR);
}
if (throttler)
job.connection_entry->setThrottler(throttler);
job.stream = std::make_shared<RemoteBlockOutputStream>(*job.connection_entry, timeouts, query_string, &settings, &context.getClientInfo());
job.stream->writePrefix();
}
CurrentMetrics::Increment metric_increment{CurrentMetrics::DistributedSend};
job.stream->write(shard_block);
}
else
{
if (!job.stream)
{
/// Forward user settings
job.local_context = std::make_unique<Context>(context);
InterpreterInsertQuery interp(query_ast, *job.local_context);
job.stream = interp.execute().out;
job.stream->writePrefix();
}
size_t num_repetitions = shard_info.getLocalNodeCount();
for (size_t i = 0; i < num_repetitions; ++i)
job.stream->write(shard_block);
}
job.blocks_written += 1;
job.rows_written += shard_block.rows();
};
}
void DistributedBlockOutputStream::writeSync(const Block & block)
{
const Settings & settings = context.getSettingsRef();
const auto & shards_info = cluster->getShardsInfo();
size_t num_shards = shards_info.size();
if (!pool)
{
/// Deferred initialization. Only for sync insertion.
initWritingJobs(block);
pool.emplace(remote_jobs_count + local_jobs_count);
if (!throttler && (settings.max_network_bandwidth || settings.max_network_bytes))
{
throttler = std::make_shared<Throttler>(settings.max_network_bandwidth, settings.max_network_bytes,
"Network bandwidth limit for a query exceeded.");
}
watch.restart();
}
watch_current_block.restart();
if (num_shards > 1)
{
auto current_selector = createSelector(block);
/// Prepare row numbers for each shard
for (size_t shard_index : ext::range(0, num_shards))
per_shard_jobs[shard_index].shard_current_block_permutation.resize(0);
for (size_t i = 0; i < block.rows(); ++i)
per_shard_jobs[current_selector[i]].shard_current_block_permutation.push_back(i);
}
try
{
/// Run jobs in parallel for each block and wait them
finished_jobs_count = 0;
for (size_t shard_index : ext::range(0, shards_info.size()))
for (JobReplica & job : per_shard_jobs[shard_index].replicas_jobs)
pool->scheduleOrThrowOnError(runWritingJob(job, block));
}
catch (...)
{
pool->wait();
throw;
}
try
{
waitForJobs();
}
catch (Exception & exception)
{
exception.addMessage(getCurrentStateDescription());
throw;
}
inserted_blocks += 1;
inserted_rows += block.rows();
}
void DistributedBlockOutputStream::writeSuffix()
{
auto log_performance = [this] ()
{
double elapsed = watch.elapsedSeconds();
LOG_DEBUG(log, "It took " << std::fixed << std::setprecision(1) << elapsed << " sec. to insert " << inserted_blocks << " blocks"
<< ", " << std::fixed << std::setprecision(1) << inserted_rows / elapsed << " rows per second"
<< ". " << getCurrentStateDescription());
};
if (insert_sync && pool)
{
finished_jobs_count = 0;
try
{
for (auto & shard_jobs : per_shard_jobs)
{
for (JobReplica & job : shard_jobs.replicas_jobs)
{
if (job.stream)
{
pool->scheduleOrThrowOnError([&job]()
{
job.stream->writeSuffix();
});
}
}
}
}
catch (...)
{
pool->wait();
throw;
}
try
{
pool->wait();
log_performance();
}
catch (Exception & exception)
{
log_performance();
exception.addMessage(getCurrentStateDescription());
throw;
}
}
}
IColumn::Selector DistributedBlockOutputStream::createSelector(const Block & source_block)
{
Block current_block_with_sharding_key_expr = source_block;
storage.getShardingKeyExpr()->execute(current_block_with_sharding_key_expr);
const auto & key_column = current_block_with_sharding_key_expr.getByName(storage.getShardingKeyColumnName());
const auto & slot_to_shard = cluster->getSlotToShard();
// If key_column.type is DataTypeLowCardinality, do shard according to its dictionaryType
#define CREATE_FOR_TYPE(TYPE) \
if (typeid_cast<const DataType ## TYPE *>(key_column.type.get())) \
return createBlockSelector<TYPE>(*key_column.column, slot_to_shard); \
else if (auto * type_low_cardinality = typeid_cast<const DataTypeLowCardinality *>(key_column.type.get())) \
if (typeid_cast<const DataType ## TYPE *>(type_low_cardinality->getDictionaryType().get())) \
return createBlockSelector<TYPE>(*key_column.column->convertToFullColumnIfLowCardinality(), slot_to_shard);
CREATE_FOR_TYPE(UInt8)
CREATE_FOR_TYPE(UInt16)
CREATE_FOR_TYPE(UInt32)
CREATE_FOR_TYPE(UInt64)
CREATE_FOR_TYPE(Int8)
CREATE_FOR_TYPE(Int16)
CREATE_FOR_TYPE(Int32)
CREATE_FOR_TYPE(Int64)
#undef CREATE_FOR_TYPE
throw Exception{"Sharding key expression does not evaluate to an integer type", ErrorCodes::TYPE_MISMATCH};
}
Blocks DistributedBlockOutputStream::splitBlock(const Block & block)
{
auto selector = createSelector(block);
/// Split block to num_shard smaller block, using 'selector'.
const size_t num_shards = cluster->getShardsInfo().size();
Blocks splitted_blocks(num_shards);
for (size_t shard_idx = 0; shard_idx < num_shards; ++shard_idx)
splitted_blocks[shard_idx] = block.cloneEmpty();
size_t columns_in_block = block.columns();
for (size_t col_idx_in_block = 0; col_idx_in_block < columns_in_block; ++col_idx_in_block)
{
MutableColumns splitted_columns = block.getByPosition(col_idx_in_block).column->scatter(num_shards, selector);
for (size_t shard_idx = 0; shard_idx < num_shards; ++shard_idx)
splitted_blocks[shard_idx].getByPosition(col_idx_in_block).column = std::move(splitted_columns[shard_idx]);
}
return splitted_blocks;
}
void DistributedBlockOutputStream::writeSplitAsync(const Block & block)
{
Blocks splitted_blocks = splitBlock(block);
const size_t num_shards = splitted_blocks.size();
for (size_t shard_idx = 0; shard_idx < num_shards; ++shard_idx)
if (splitted_blocks[shard_idx].rows())
writeAsyncImpl(splitted_blocks[shard_idx], shard_idx);
++inserted_blocks;
}
void DistributedBlockOutputStream::writeAsyncImpl(const Block & block, const size_t shard_id)
{
const auto & shard_info = cluster->getShardsInfo()[shard_id];
if (shard_info.hasInternalReplication())
{
if (shard_info.getLocalNodeCount() > 0)
{
/// Prefer insert into current instance directly
writeToLocal(block, shard_info.getLocalNodeCount());
}
else
{
if (shard_info.dir_name_for_internal_replication.empty())
throw Exception("Directory name for async inserts is empty, table " + storage.getStorageID().getNameForLogs(), ErrorCodes::LOGICAL_ERROR);
writeToShard(block, {shard_info.dir_name_for_internal_replication});
}
}
else
{
if (shard_info.getLocalNodeCount() > 0)
writeToLocal(block, shard_info.getLocalNodeCount());
std::vector<std::string> dir_names;
for (const auto & address : cluster->getShardsAddresses()[shard_id])
if (!address.is_local)
dir_names.push_back(address.toFullString(context.getSettingsRef().use_compact_format_in_distributed_parts_names));
if (!dir_names.empty())
writeToShard(block, dir_names);
}
}
void DistributedBlockOutputStream::writeToLocal(const Block & block, const size_t repeats)
{
/// Async insert does not support settings forwarding yet whereas sync one supports
InterpreterInsertQuery interp(query_ast, context);
auto block_io = interp.execute();
block_io.out->writePrefix();
for (size_t i = 0; i < repeats; ++i)
block_io.out->write(block);
block_io.out->writeSuffix();
}
void DistributedBlockOutputStream::writeToShard(const Block & block, const std::vector<std::string> & dir_names)
{
/** tmp directory is used to ensure atomicity of transactions
* and keep monitor thread out from reading incomplete data
*/
std::string first_file_tmp_path{};
auto first = true;
/// write first file, hardlink the others
for (const auto & dir_name : dir_names)
{
const auto & [disk, data_path] = storage.getPath();
const std::string path(disk + data_path + dir_name + '/');
/// ensure shard subdirectory creation and notify storage
if (Poco::File(path).createDirectory())
storage.requireDirectoryMonitor(disk, dir_name);
const auto & file_name = toString(storage.file_names_increment.get()) + ".bin";
const auto & block_file_path = path + file_name;
/** on first iteration write block to a temporary directory for subsequent hardlinking to ensure
* the inode is not freed until we're done */
if (first)
{
first = false;
const auto & tmp_path = path + "tmp/";
Poco::File(tmp_path).createDirectory();
const auto & block_file_tmp_path = tmp_path + file_name;
first_file_tmp_path = block_file_tmp_path;
WriteBufferFromFile out{block_file_tmp_path};
CompressedWriteBuffer compress{out};
NativeBlockOutputStream stream{compress, ClickHouseRevision::get(), block.cloneEmpty()};
/// Prepare the header.
/// We wrap the header into a string for compatibility with older versions:
/// a shard will able to read the header partly and ignore other parts based on its version.
WriteBufferFromOwnString header_buf;
writeVarUInt(ClickHouseRevision::get(), header_buf);
writeStringBinary(query_string, header_buf);
context.getSettingsRef().serialize(header_buf);
context.getClientInfo().write(header_buf, ClickHouseRevision::get());
/// Add new fields here, for example:
/// writeVarUInt(my_new_data, header_buf);
/// Write the header.
const StringRef header = header_buf.stringRef();
writeVarUInt(DBMS_DISTRIBUTED_SIGNATURE_HEADER, out);
writeStringBinary(header, out);
writePODBinary(CityHash_v1_0_2::CityHash128(header.data, header.size), out);
stream.writePrefix();
stream.write(block);
stream.writeSuffix();
}
if (link(first_file_tmp_path.data(), block_file_path.data()))
throwFromErrnoWithPath("Could not link " + block_file_path + " to " + first_file_tmp_path, block_file_path,
ErrorCodes::CANNOT_LINK);
}
/** remove the temporary file, enabling the OS to reclaim inode after all threads
* have removed their corresponding files */
Poco::File(first_file_tmp_path).remove();
}
}