rocksdb/db/flush_job.h
Yanqin Jin e633983cf1 Add support to flush multiple CFs atomically (#4262)
Summary:
Leverage existing `FlushJob` to implement atomic flush of multiple column families.

This PR depends on other PRs and is a subset of #3752 . This PR itself is not sufficient in fulfilling atomic flush.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4262

Differential Revision: D9283109

Pulled By: riversand963

fbshipit-source-id: 65401f913e4160b0a61c0be6cd02adc15dad28ed
2018-10-15 20:01:17 -07:00

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5.3 KiB
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// 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 <atomic>
#include <deque>
#include <limits>
#include <set>
#include <utility>
#include <vector>
#include <string>
#include "db/column_family.h"
#include "db/dbformat.h"
#include "db/flush_scheduler.h"
#include "db/internal_stats.h"
#include "db/job_context.h"
#include "db/log_writer.h"
#include "db/logs_with_prep_tracker.h"
#include "db/memtable_list.h"
#include "db/snapshot_impl.h"
#include "db/version_edit.h"
#include "db/write_controller.h"
#include "db/write_thread.h"
#include "monitoring/instrumented_mutex.h"
#include "options/db_options.h"
#include "port/port.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/memtablerep.h"
#include "rocksdb/transaction_log.h"
#include "table/scoped_arena_iterator.h"
#include "util/autovector.h"
#include "util/event_logger.h"
#include "util/stop_watch.h"
#include "util/thread_local.h"
namespace rocksdb {
class DBImpl;
class MemTable;
class SnapshotChecker;
class TableCache;
class Version;
class VersionEdit;
class VersionSet;
class Arena;
class FlushJob {
public:
// TODO(icanadi) make effort to reduce number of parameters here
// IMPORTANT: mutable_cf_options needs to be alive while FlushJob is alive
FlushJob(const std::string& dbname, ColumnFamilyData* cfd,
const ImmutableDBOptions& db_options,
const MutableCFOptions& mutable_cf_options,
const uint64_t* max_memtable_id, const EnvOptions& env_options,
VersionSet* versions, InstrumentedMutex* db_mutex,
std::atomic<bool>* shutting_down,
std::vector<SequenceNumber> existing_snapshots,
SequenceNumber earliest_write_conflict_snapshot,
SnapshotChecker* snapshot_checker, JobContext* job_context,
LogBuffer* log_buffer, Directory* db_directory,
Directory* output_file_directory, CompressionType output_compression,
Statistics* stats, EventLogger* event_logger, bool measure_io_stats,
const bool sync_output_directory, const bool write_manifest);
~FlushJob();
// Require db_mutex held.
// Once PickMemTable() is called, either Run() or Cancel() has to be called.
void PickMemTable();
Status Run(LogsWithPrepTracker* prep_tracker = nullptr,
FileMetaData* file_meta = nullptr);
void Cancel();
TableProperties GetTableProperties() const { return table_properties_; }
const autovector<MemTable*>& GetMemTables() const { return mems_; }
private:
void ReportStartedFlush();
void ReportFlushInputSize(const autovector<MemTable*>& mems);
void RecordFlushIOStats();
Status WriteLevel0Table();
const std::string& dbname_;
ColumnFamilyData* cfd_;
const ImmutableDBOptions& db_options_;
const MutableCFOptions& mutable_cf_options_;
// Pointer to a variable storing the largest memtable id to flush in this
// flush job. RocksDB uses this variable to select the memtables to flush in
// this job. All memtables in this column family with an ID smaller than or
// equal to *max_memtable_id_ will be selected for flush. If null, then all
// memtables in the column family will be selected.
const uint64_t* max_memtable_id_;
const EnvOptions env_options_;
VersionSet* versions_;
InstrumentedMutex* db_mutex_;
std::atomic<bool>* shutting_down_;
std::vector<SequenceNumber> existing_snapshots_;
SequenceNumber earliest_write_conflict_snapshot_;
SnapshotChecker* snapshot_checker_;
JobContext* job_context_;
LogBuffer* log_buffer_;
Directory* db_directory_;
Directory* output_file_directory_;
CompressionType output_compression_;
Statistics* stats_;
EventLogger* event_logger_;
TableProperties table_properties_;
bool measure_io_stats_;
// True if this flush job should call fsync on the output directory. False
// otherwise.
// Usually sync_output_directory_ is true. A flush job needs to call sync on
// the output directory before committing to the MANIFEST.
// However, an individual flush job does not have to call sync on the output
// directory if it is part of an atomic flush. After all flush jobs in the
// atomic flush succeed, call sync once on each distinct output directory.
const bool sync_output_directory_;
// True if this flush job should write to MANIFEST after successfully
// flushing memtables. False otherwise.
// Usually write_manifest_ is true. A flush job commits to the MANIFEST after
// flushing the memtables.
// However, an individual flush job cannot rashly write to the MANIFEST
// immediately after it finishes the flush if it is part of an atomic flush.
// In this case, only after all flush jobs succeed in flush can RocksDB
// commit to the MANIFEST.
const bool write_manifest_;
// Variables below are set by PickMemTable():
FileMetaData meta_;
autovector<MemTable*> mems_;
VersionEdit* edit_;
Version* base_;
bool pick_memtable_called;
};
} // namespace rocksdb