rocksdb/monitoring/stats_dump_scheduler.h
Jay Zhuang 69760b4d05 Introduce a global StatsDumpScheduler for stats dumping (#7223)
Summary:
Have a global StatsDumpScheduler for all DB instance stats dumping, including `DumpStats()` and `PersistStats()`. Before this, there're 2 dedicate threads for every DB instance, one for DumpStats() one for PersistStats(), which could create lots of threads if there're hundreds DB instances.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7223

Reviewed By: riversand963

Differential Revision: D23056737

Pulled By: jay-zhuang

fbshipit-source-id: 0faa2311142a73433ebb3317361db7cbf43faeba
2020-08-14 20:12:44 -07:00

65 lines
2.0 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#ifndef ROCKSDB_LITE
#include "db/db_impl/db_impl.h"
#include "util/timer.h"
namespace ROCKSDB_NAMESPACE {
// StatsDumpScheduler is a singleton object, which is scheduling/running
// DumpStats() and PersistStats() for all DB instances. All DB instances uses
// the same object from `Default()`.
// Internally, it uses a single threaded timer object to run the stats dump
// functions. Timer thread won't be started if there's no function needs to run,
// for example, option.stats_dump_period_sec and option.stats_persist_period_sec
// are set to 0.
class StatsDumpScheduler {
public:
static StatsDumpScheduler* Default();
StatsDumpScheduler() = delete;
StatsDumpScheduler(const StatsDumpScheduler&) = delete;
StatsDumpScheduler(StatsDumpScheduler&&) = delete;
StatsDumpScheduler& operator=(const StatsDumpScheduler&) = delete;
StatsDumpScheduler& operator=(StatsDumpScheduler&&) = delete;
void Register(DBImpl* dbi, unsigned int stats_dump_period_sec,
unsigned int stats_persist_period_sec);
void Unregister(DBImpl* dbi);
protected:
std::unique_ptr<Timer> timer;
explicit StatsDumpScheduler(Env* env);
private:
std::string GetTaskName(DBImpl* dbi, const std::string& func_name);
};
#ifndef NDEBUG
// StatsDumpTestScheduler is for unittest, which can specify the Env like
// SafeMockTimeEnv. It also contains functions for unittest.
class StatsDumpTestScheduler : public StatsDumpScheduler {
public:
static StatsDumpTestScheduler* Default(Env* env);
void TEST_WaitForRun(std::function<void()> callback) const;
size_t TEST_GetValidTaskNum() const;
private:
explicit StatsDumpTestScheduler(Env* env);
};
#endif // !NDEBUG
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE