mirror of
https://github.com/facebook/rocksdb.git
synced 2024-12-02 01:16:16 +00:00
671d15cbdd
Summary: This PR continues the work in https://github.com/facebook/rocksdb/pull/4748 and https://github.com/facebook/rocksdb/pull/4535 by adding a new DBOption `persist_stats_to_disk` which instructs RocksDB to persist stats history to RocksDB itself. When statistics is enabled, and both options `stats_persist_period_sec` and `persist_stats_to_disk` are set, RocksDB will periodically write stats to a built-in column family in the following form: key -> (timestamp in microseconds)#(stats name), value -> stats value. The existing API `GetStatsHistory` will detect the current value of `persist_stats_to_disk` and either read from in-memory data structure or from the hidden column family on disk. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5046 Differential Revision: D15863138 Pulled By: miasantreble fbshipit-source-id: bb82abdb3f2ca581aa42531734ac799f113e931b
70 lines
2.5 KiB
C++
70 lines
2.5 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).
|
|
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
|
|
#pragma once
|
|
|
|
#include <map>
|
|
#include <string>
|
|
|
|
#include "rocksdb/statistics.h"
|
|
#include "rocksdb/status.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
class DBImpl;
|
|
|
|
// StatsHistoryIterator is the main interface for users to programmatically
|
|
// access statistics snapshots that was automatically stored by RocksDB.
|
|
// Depending on options, the stats can be in memory or on disk.
|
|
// The stats snapshots are indexed by time that they were recorded, and each
|
|
// stats snapshot contains individual stat name and value at the time of
|
|
// recording.
|
|
// Example:
|
|
// std::unique_ptr<StatsHistoryIterator> stats_iter;
|
|
// Status s = db->GetStatsHistory(0 /* start_time */,
|
|
// env->NowMicros() /* end_time*/,
|
|
// &stats_iter);
|
|
// if (s.ok) {
|
|
// for (; stats_iter->Valid(); stats_iter->Next()) {
|
|
// uint64_t stats_time = stats_iter->GetStatsTime();
|
|
// const std::map<std::string, uint64_t>& stats_map =
|
|
// stats_iter->GetStatsMap();
|
|
// process(stats_time, stats_map);
|
|
// }
|
|
// }
|
|
class StatsHistoryIterator {
|
|
public:
|
|
StatsHistoryIterator() {}
|
|
virtual ~StatsHistoryIterator() {}
|
|
|
|
virtual bool Valid() const = 0;
|
|
|
|
// Moves to the next stats history record. After this call, Valid() is
|
|
// true iff the iterator was not positioned at the last entry in the source.
|
|
// REQUIRES: Valid()
|
|
virtual void Next() = 0;
|
|
|
|
// Return the time stamp (in seconds) when stats history is recorded.
|
|
// REQUIRES: Valid()
|
|
virtual uint64_t GetStatsTime() const = 0;
|
|
|
|
virtual int GetFormatVersion() const { return -1; }
|
|
|
|
// Return the current stats history as an std::map which specifies the
|
|
// mapping from stats name to stats value . The underlying storage
|
|
// for the returned map is valid only until the next modification of
|
|
// the iterator.
|
|
// REQUIRES: Valid()
|
|
virtual const std::map<std::string, uint64_t>& GetStatsMap() const = 0;
|
|
|
|
// If an error has occurred, return it. Else return an ok status.
|
|
virtual Status status() const = 0;
|
|
};
|
|
|
|
} // namespace rocksdb
|