ClickHouse/programs/copier/ClusterCopier.h
Nikita Mikhaylov 15de7e4fa7 first try
2020-04-21 20:37:40 +03:00

227 lines
8.7 KiB
C++

#pragma once
#include "Aliases.h"
#include "Internals.h"
#include "TaskCluster.h"
#include "TaskTableAndShard.h"
#include "ShardPartition.h"
#include "ShardPartitionPiece.h"
#include "ZooKeeperStaff.h"
namespace DB
{
class ClusterCopier
{
public:
ClusterCopier(const String & task_path_,
const String & host_id_,
const String & proxy_database_name_,
Context & context_)
:
task_zookeeper_path(task_path_),
host_id(host_id_),
working_database_name(proxy_database_name_),
context(context_),
log(&Poco::Logger::get("ClusterCopier")) {}
void init();
template <typename T>
decltype(auto) retry(T && func, UInt64 max_tries = 100);
void discoverShardPartitions(const ConnectionTimeouts & timeouts, const TaskShardPtr & task_shard);
/// Compute set of partitions, assume set of partitions aren't changed during the processing
void discoverTablePartitions(const ConnectionTimeouts & timeouts, TaskTable & task_table, UInt64 num_threads = 0);
void uploadTaskDescription(const std::string & task_path, const std::string & task_file, const bool force);
void reloadTaskDescription();
void updateConfigIfNeeded();
void process(const ConnectionTimeouts & timeouts);
/// Disables DROP PARTITION commands that used to clear data after errors
void setSafeMode(bool is_safe_mode_ = true)
{
is_safe_mode = is_safe_mode_;
}
void setCopyFaultProbability(double copy_fault_probability_)
{
copy_fault_probability = copy_fault_probability_;
}
void setMoveFaultProbability(double move_fault_probability_)
{
move_fault_probability = move_fault_probability_;
}
void setExperimentalUseSampleOffset(bool value)
{
experimental_use_sample_offset = value;
}
protected:
String getWorkersPath() const
{
return task_cluster->task_zookeeper_path + "/task_active_workers";
}
String getWorkersPathVersion() const
{
return getWorkersPath() + "_version";
}
String getCurrentWorkerNodePath() const
{
return getWorkersPath() + "/" + host_id;
}
zkutil::EphemeralNodeHolder::Ptr createTaskWorkerNodeAndWaitIfNeed(
const zkutil::ZooKeeperPtr & zookeeper,
const String & description,
bool unprioritized);
/*
* Checks that partition piece or some other entity is clean.
* The only requirement is that you have to pass is_dirty_flag_path and is_dirty_cleaned_path to the function.
* And is_dirty_flag_path is a parent of is_dirty_cleaned_path.
* */
static bool checkPartitionPieceIsClean(
const zkutil::ZooKeeperPtr & zookeeper,
const CleanStateClock & clean_state_clock,
const String & task_status_path);
bool checkAllPiecesInPartitionAreDone(const TaskTable & task_table, const String & partition_name, const TasksShard & shards_with_partition);
/** Checks that the whole partition of a table was copied. We should do it carefully due to dirty lock.
* State of some task could change during the processing.
* We have to ensure that all shards have the finished state and there is no dirty flag.
* Moreover, we have to check status twice and check zxid, because state can change during the checking.
*/
/* The same as function above
* Assume that we don't know on which shards do we have partition certain piece.
* We'll check them all (I mean shards that contain the whole partition)
* And shards that don't have certain piece MUST mark that piece is_done true.
* */
bool checkPartitionPieceIsDone(const TaskTable & task_table, const String & partition_name,
size_t piece_number, const TasksShard & shards_with_partition);
/*Alter successful insertion to helping tables it will move all pieces to destination table*/
TaskStatus tryMoveAllPiecesToDestinationTable(const TaskTable & task_table, const String & partition_name);
/// Removes MATERIALIZED and ALIAS columns from create table query
static ASTPtr removeAliasColumnsFromCreateQuery(const ASTPtr & query_ast);
bool tryDropPartitionPiece(ShardPartition & task_partition, const size_t current_piece_number,
const zkutil::ZooKeeperPtr & zookeeper, const CleanStateClock & clean_state_clock);
static constexpr UInt64 max_table_tries = 1000;
static constexpr UInt64 max_shard_partition_tries = 600;
static constexpr UInt64 max_shard_partition_piece_tries_for_alter = 100;
bool tryProcessTable(const ConnectionTimeouts & timeouts, TaskTable & task_table);
/// Job for copying partition from particular shard.
TaskStatus tryProcessPartitionTask(const ConnectionTimeouts & timeouts,
ShardPartition & task_partition,
bool is_unprioritized_task);
TaskStatus iterateThroughAllPiecesInPartition(const ConnectionTimeouts & timeouts,
ShardPartition & task_partition,
bool is_unprioritized_task);
TaskStatus processPartitionPieceTaskImpl(const ConnectionTimeouts & timeouts,
ShardPartition & task_partition,
const size_t current_piece_number,
bool is_unprioritized_task);
void dropAndCreateLocalTable(const ASTPtr & create_ast);
void dropLocalTableIfExists(const DatabaseAndTableName & table_name) const;
void dropHelpingTables(const TaskTable & task_table);
/// Is used for usage less disk space.
/// After all pieces were successfully moved to original destination
/// table we can get rid of partition pieces (partitions in helping tables).
void dropParticularPartitionPieceFromAllHelpingTables(const TaskTable & task_table, const String & partition_name);
String getRemoteCreateTable(const DatabaseAndTableName & table, Connection & connection, const Settings * settings = nullptr);
ASTPtr getCreateTableForPullShard(const ConnectionTimeouts & timeouts, TaskShard & task_shard);
/// If it is implicitly asked to create split Distributed table for certain piece on current shard, we will do it.
void createShardInternalTables(const ConnectionTimeouts & timeouts, TaskShard & task_shard, bool create_split = true);
std::set<String> getShardPartitions(const ConnectionTimeouts & timeouts, TaskShard & task_shard);
bool checkShardHasPartition(const ConnectionTimeouts & timeouts, TaskShard & task_shard, const String & partition_quoted_name);
bool checkPresentPartitionPiecesOnCurrentShard(const ConnectionTimeouts & timeouts,
TaskShard & task_shard, const String & partition_quoted_name, size_t current_piece_number);
/*
* This class is used in executeQueryOnCluster function
* You can execute query on each shard (no sense it is executed on each replica of a shard or not)
* or you can execute query on each replica on each shard.
* First mode is useful for INSERTS queries.
* */
enum ClusterExecutionMode
{
ON_EACH_SHARD,
ON_EACH_NODE
};
/** Executes simple query (without output streams, for example DDL queries) on each shard of the cluster
* Returns number of shards for which at least one replica executed query successfully
*/
UInt64 executeQueryOnCluster(
const ClusterPtr & cluster,
const String & query,
const ASTPtr & query_ast_ = nullptr,
const Settings * settings = nullptr,
PoolMode pool_mode = PoolMode::GET_ALL,
ClusterExecutionMode execution_mode = ClusterExecutionMode::ON_EACH_SHARD,
UInt64 max_successful_executions_per_shard = 0) const;
private:
String task_zookeeper_path;
String task_description_path;
String host_id;
String working_database_name;
/// Auto update config stuff
UInt64 task_description_current_version = 1;
std::atomic<UInt64> task_description_version{1};
Coordination::WatchCallback task_description_watch_callback;
/// ZooKeeper session used to set the callback
zkutil::ZooKeeperPtr task_description_watch_zookeeper;
ConfigurationPtr task_cluster_initial_config;
ConfigurationPtr task_cluster_current_config;
Coordination::Stat task_description_current_stat{};
std::unique_ptr<TaskCluster> task_cluster;
bool is_safe_mode = false;
double copy_fault_probability = 0.0;
double move_fault_probability = 0.0;
bool experimental_use_sample_offset{false};
Context & context;
Poco::Logger * log;
std::chrono::milliseconds default_sleep_time{1000};
};
}