229e6fbe0e
Summary: Adding a light weight API to get last live WAL file name and size. Meant to be used as a helper for backup/restore tooling in a larger ecosystem such as MySQL with a MyRocks storage engine. Specifically within MySQL's backup/restore mechanism, this call can be made with a write lock on the mysql db to get a transactionally consistent snapshot of the current WAL file position along with other non-rocksdb log/data files. Without this, the alternative would be to take the aforementioned lock, scan the WAL dir for all files, find the last file and note its exact size as the rocksdb 'checkpoint'. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5765 Differential Revision: D17172717 Pulled By: affandar fbshipit-source-id: f2fabafd4c0e6fc45f126670c8c88a9f84cb8a37
113 lines
3.8 KiB
C++
113 lines
3.8 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 <atomic>
|
|
#include <deque>
|
|
#include <limits>
|
|
#include <set>
|
|
#include <utility>
|
|
#include <vector>
|
|
#include <string>
|
|
#include <memory>
|
|
|
|
#include "db/version_set.h"
|
|
#include "file/file_util.h"
|
|
#include "options/db_options.h"
|
|
#include "port/port.h"
|
|
#include "rocksdb/env.h"
|
|
#include "rocksdb/status.h"
|
|
#include "rocksdb/transaction_log.h"
|
|
#include "rocksdb/types.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
#ifndef ROCKSDB_LITE
|
|
|
|
// WAL manager provides the abstraction for reading the WAL files as a single
|
|
// unit. Internally, it opens and reads the files using Reader or Writer
|
|
// abstraction.
|
|
class WalManager {
|
|
public:
|
|
WalManager(const ImmutableDBOptions& db_options,
|
|
const EnvOptions& env_options, const bool seq_per_batch = false)
|
|
: db_options_(db_options),
|
|
env_options_(env_options),
|
|
env_(db_options.env),
|
|
purge_wal_files_last_run_(0),
|
|
seq_per_batch_(seq_per_batch),
|
|
wal_in_db_path_(IsWalDirSameAsDBPath(&db_options)) {}
|
|
|
|
Status GetSortedWalFiles(VectorLogPtr& files);
|
|
|
|
// Allow user to tail transaction log to find all recent changes to the
|
|
// database that are newer than `seq_number`.
|
|
Status GetUpdatesSince(
|
|
SequenceNumber seq_number, std::unique_ptr<TransactionLogIterator>* iter,
|
|
const TransactionLogIterator::ReadOptions& read_options,
|
|
VersionSet* version_set);
|
|
|
|
void PurgeObsoleteWALFiles();
|
|
|
|
void ArchiveWALFile(const std::string& fname, uint64_t number);
|
|
|
|
Status DeleteFile(const std::string& fname, uint64_t number);
|
|
|
|
Status GetLiveWalFile(uint64_t number, std::unique_ptr<LogFile>* log_file);
|
|
|
|
Status TEST_ReadFirstRecord(const WalFileType type, const uint64_t number,
|
|
SequenceNumber* sequence) {
|
|
return ReadFirstRecord(type, number, sequence);
|
|
}
|
|
|
|
Status TEST_ReadFirstLine(const std::string& fname, const uint64_t number,
|
|
SequenceNumber* sequence) {
|
|
return ReadFirstLine(fname, number, sequence);
|
|
}
|
|
|
|
private:
|
|
Status GetSortedWalsOfType(const std::string& path, VectorLogPtr& log_files,
|
|
WalFileType type);
|
|
// Requires: all_logs should be sorted with earliest log file first
|
|
// Retains all log files in all_logs which contain updates with seq no.
|
|
// Greater Than or Equal to the requested SequenceNumber.
|
|
Status RetainProbableWalFiles(VectorLogPtr& all_logs,
|
|
const SequenceNumber target);
|
|
|
|
Status ReadFirstRecord(const WalFileType type, const uint64_t number,
|
|
SequenceNumber* sequence);
|
|
|
|
Status ReadFirstLine(const std::string& fname, const uint64_t number,
|
|
SequenceNumber* sequence);
|
|
|
|
// ------- state from DBImpl ------
|
|
const ImmutableDBOptions& db_options_;
|
|
const EnvOptions& env_options_;
|
|
Env* env_;
|
|
|
|
// ------- WalManager state -------
|
|
// cache for ReadFirstRecord() calls
|
|
std::unordered_map<uint64_t, SequenceNumber> read_first_record_cache_;
|
|
port::Mutex read_first_record_cache_mutex_;
|
|
|
|
// last time when PurgeObsoleteWALFiles ran.
|
|
uint64_t purge_wal_files_last_run_;
|
|
|
|
bool seq_per_batch_;
|
|
|
|
bool wal_in_db_path_;
|
|
|
|
// obsolete files will be deleted every this seconds if ttl deletion is
|
|
// enabled and archive size_limit is disabled.
|
|
static const uint64_t kDefaultIntervalToDeleteObsoleteWAL = 600;
|
|
};
|
|
|
|
#endif // ROCKSDB_LITE
|
|
} // namespace rocksdb
|