ClickHouse/dbms/Storages/MergeTree/ReplicatedMergeTreePartCheckThread.h
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

101 lines
3.0 KiB
C++

#pragma once
#include <set>
#include <map>
#include <list>
#include <mutex>
#include <thread>
#include <atomic>
#include <boost/noncopyable.hpp>
#include <Poco/Event.h>
#include <Core/Types.h>
#include <common/logger_useful.h>
#include <Core/BackgroundSchedulePool.h>
#include <Storages/CheckResults.h>
namespace DB
{
class StorageReplicatedMergeTree;
/** Checks the integrity of the parts requested for validation.
*
* Identifies the extra parts and removes them from the working set.
* Find the missing parts and add them for download from replicas.
* Checks the integrity of the data and, in the event of a violation,
* removes a part from the working set and adds it for download from replicas.
*/
class ReplicatedMergeTreePartCheckThread
{
public:
ReplicatedMergeTreePartCheckThread(StorageReplicatedMergeTree & storage_);
~ReplicatedMergeTreePartCheckThread();
/// Processing of the queue to be checked is done in the background thread, which you must first start.
void start();
void stop();
/// Don't create more than one instance of this object simultaneously.
struct TemporarilyStop : private boost::noncopyable
{
ReplicatedMergeTreePartCheckThread * parent;
TemporarilyStop(ReplicatedMergeTreePartCheckThread * parent_) : parent(parent_)
{
parent->stop();
}
TemporarilyStop(TemporarilyStop && old) : parent(old.parent)
{
old.parent = nullptr;
}
~TemporarilyStop()
{
if (parent)
parent->start();
}
};
TemporarilyStop temporarilyStop() { return TemporarilyStop(this); }
/// Add a part (for which there are suspicions that it is missing, damaged or not needed) in the queue for check.
/// delay_to_check_seconds - check no sooner than the specified number of seconds.
void enqueuePart(const String & name, time_t delay_to_check_seconds = 0);
/// Get the number of parts in the queue for check.
size_t size() const;
/// Check part by name
CheckResult checkPart(const String & part_name);
private:
void run();
void searchForMissingPart(const String & part_name);
StorageReplicatedMergeTree & storage;
String log_name;
Logger * log;
using StringSet = std::set<String>;
using PartToCheck = std::pair<String, time_t>; /// The name of the part and the minimum time to check (or zero, if not important).
using PartsToCheckQueue = std::list<PartToCheck>;
/** Parts for which you want to check one of two:
* - If we have the part, check, its data with its checksums, and them with ZooKeeper.
* - If we do not have a part, check to see if it (or the part covering it) exists anywhere on another replicas.
*/
mutable std::mutex parts_mutex;
StringSet parts_set;
PartsToCheckQueue parts_queue;
std::mutex start_stop_mutex;
std::atomic<bool> need_stop { false };
BackgroundSchedulePool::TaskHolder task;
};
}