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Diffstat (limited to 'src/rocksdb/db/wal_manager.cc')
-rw-r--r-- | src/rocksdb/db/wal_manager.cc | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/src/rocksdb/db/wal_manager.cc b/src/rocksdb/db/wal_manager.cc new file mode 100644 index 00000000..62511819 --- /dev/null +++ b/src/rocksdb/db/wal_manager.cc @@ -0,0 +1,487 @@ +// 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. + +#include "db/wal_manager.h" + +#ifndef __STDC_FORMAT_MACROS +#define __STDC_FORMAT_MACROS +#endif + +#include <inttypes.h> +#include <algorithm> +#include <vector> +#include <memory> + +#include "db/log_reader.h" +#include "db/log_writer.h" +#include "db/transaction_log_impl.h" +#include "db/write_batch_internal.h" +#include "port/port.h" +#include "rocksdb/env.h" +#include "rocksdb/options.h" +#include "rocksdb/write_batch.h" +#include "util/cast_util.h" +#include "util/coding.h" +#include "util/file_reader_writer.h" +#include "util/file_util.h" +#include "util/filename.h" +#include "util/logging.h" +#include "util/mutexlock.h" +#include "util/string_util.h" +#include "util/sync_point.h" + +namespace rocksdb { + +#ifndef ROCKSDB_LITE + +Status WalManager::DeleteFile(const std::string& fname, uint64_t number) { + auto s = env_->DeleteFile(db_options_.wal_dir + "/" + fname); + if (s.ok()) { + MutexLock l(&read_first_record_cache_mutex_); + read_first_record_cache_.erase(number); + } + return s; +} + +Status WalManager::GetSortedWalFiles(VectorLogPtr& files) { + // First get sorted files in db dir, then get sorted files from archived + // dir, to avoid a race condition where a log file is moved to archived + // dir in between. + Status s; + // list wal files in main db dir. + VectorLogPtr logs; + s = GetSortedWalsOfType(db_options_.wal_dir, logs, kAliveLogFile); + if (!s.ok()) { + return s; + } + + // Reproduce the race condition where a log file is moved + // to archived dir, between these two sync points, used in + // (DBTest,TransactionLogIteratorRace) + TEST_SYNC_POINT("WalManager::GetSortedWalFiles:1"); + TEST_SYNC_POINT("WalManager::GetSortedWalFiles:2"); + + files.clear(); + // list wal files in archive dir. + std::string archivedir = ArchivalDirectory(db_options_.wal_dir); + Status exists = env_->FileExists(archivedir); + if (exists.ok()) { + s = GetSortedWalsOfType(archivedir, files, kArchivedLogFile); + if (!s.ok()) { + return s; + } + } else if (!exists.IsNotFound()) { + assert(s.IsIOError()); + return s; + } + + uint64_t latest_archived_log_number = 0; + if (!files.empty()) { + latest_archived_log_number = files.back()->LogNumber(); + ROCKS_LOG_INFO(db_options_.info_log, "Latest Archived log: %" PRIu64, + latest_archived_log_number); + } + + files.reserve(files.size() + logs.size()); + for (auto& log : logs) { + if (log->LogNumber() > latest_archived_log_number) { + files.push_back(std::move(log)); + } else { + // When the race condition happens, we could see the + // same log in both db dir and archived dir. Simply + // ignore the one in db dir. Note that, if we read + // archived dir first, we would have missed the log file. + ROCKS_LOG_WARN(db_options_.info_log, "%s already moved to archive", + log->PathName().c_str()); + } + } + + return s; +} + +Status WalManager::GetUpdatesSince( + SequenceNumber seq, std::unique_ptr<TransactionLogIterator>* iter, + const TransactionLogIterator::ReadOptions& read_options, + VersionSet* version_set) { + + // Get all sorted Wal Files. + // Do binary search and open files and find the seq number. + + std::unique_ptr<VectorLogPtr> wal_files(new VectorLogPtr); + Status s = GetSortedWalFiles(*wal_files); + if (!s.ok()) { + return s; + } + + s = RetainProbableWalFiles(*wal_files, seq); + if (!s.ok()) { + return s; + } + iter->reset(new TransactionLogIteratorImpl( + db_options_.wal_dir, &db_options_, read_options, env_options_, seq, + std::move(wal_files), version_set, seq_per_batch_)); + return (*iter)->status(); +} + +// 1. Go through all archived files and +// a. if ttl is enabled, delete outdated files +// b. if archive size limit is enabled, delete empty files, +// compute file number and size. +// 2. If size limit is enabled: +// a. compute how many files should be deleted +// b. get sorted non-empty archived logs +// c. delete what should be deleted +void WalManager::PurgeObsoleteWALFiles() { + bool const ttl_enabled = db_options_.wal_ttl_seconds > 0; + bool const size_limit_enabled = db_options_.wal_size_limit_mb > 0; + if (!ttl_enabled && !size_limit_enabled) { + return; + } + + int64_t current_time; + Status s = env_->GetCurrentTime(¤t_time); + if (!s.ok()) { + ROCKS_LOG_ERROR(db_options_.info_log, "Can't get current time: %s", + s.ToString().c_str()); + assert(false); + return; + } + uint64_t const now_seconds = static_cast<uint64_t>(current_time); + uint64_t const time_to_check = (ttl_enabled && !size_limit_enabled) + ? db_options_.wal_ttl_seconds / 2 + : kDefaultIntervalToDeleteObsoleteWAL; + + if (purge_wal_files_last_run_ + time_to_check > now_seconds) { + return; + } + + purge_wal_files_last_run_ = now_seconds; + + std::string archival_dir = ArchivalDirectory(db_options_.wal_dir); + std::vector<std::string> files; + s = env_->GetChildren(archival_dir, &files); + if (!s.ok()) { + ROCKS_LOG_ERROR(db_options_.info_log, "Can't get archive files: %s", + s.ToString().c_str()); + assert(false); + return; + } + + size_t log_files_num = 0; + uint64_t log_file_size = 0; + + for (auto& f : files) { + uint64_t number; + FileType type; + if (ParseFileName(f, &number, &type) && type == kLogFile) { + std::string const file_path = archival_dir + "/" + f; + if (ttl_enabled) { + uint64_t file_m_time; + s = env_->GetFileModificationTime(file_path, &file_m_time); + if (!s.ok()) { + ROCKS_LOG_WARN(db_options_.info_log, + "Can't get file mod time: %s: %s", file_path.c_str(), + s.ToString().c_str()); + continue; + } + if (now_seconds - file_m_time > db_options_.wal_ttl_seconds) { + s = DeleteDBFile(&db_options_, file_path, archival_dir, false); + if (!s.ok()) { + ROCKS_LOG_WARN(db_options_.info_log, "Can't delete file: %s: %s", + file_path.c_str(), s.ToString().c_str()); + continue; + } else { + MutexLock l(&read_first_record_cache_mutex_); + read_first_record_cache_.erase(number); + } + continue; + } + } + + if (size_limit_enabled) { + uint64_t file_size; + s = env_->GetFileSize(file_path, &file_size); + if (!s.ok()) { + ROCKS_LOG_ERROR(db_options_.info_log, + "Unable to get file size: %s: %s", file_path.c_str(), + s.ToString().c_str()); + return; + } else { + if (file_size > 0) { + log_file_size = std::max(log_file_size, file_size); + ++log_files_num; + } else { + s = DeleteDBFile(&db_options_, file_path, archival_dir, false); + if (!s.ok()) { + ROCKS_LOG_WARN(db_options_.info_log, + "Unable to delete file: %s: %s", file_path.c_str(), + s.ToString().c_str()); + continue; + } else { + MutexLock l(&read_first_record_cache_mutex_); + read_first_record_cache_.erase(number); + } + } + } + } + } + } + + if (0 == log_files_num || !size_limit_enabled) { + return; + } + + size_t const files_keep_num = + static_cast<size_t>(db_options_.wal_size_limit_mb * 1024 * 1024 / log_file_size); + if (log_files_num <= files_keep_num) { + return; + } + + size_t files_del_num = log_files_num - files_keep_num; + VectorLogPtr archived_logs; + GetSortedWalsOfType(archival_dir, archived_logs, kArchivedLogFile); + + if (files_del_num > archived_logs.size()) { + ROCKS_LOG_WARN(db_options_.info_log, + "Trying to delete more archived log files than " + "exist. Deleting all"); + files_del_num = archived_logs.size(); + } + + for (size_t i = 0; i < files_del_num; ++i) { + std::string const file_path = archived_logs[i]->PathName(); + s = DeleteDBFile(&db_options_, db_options_.wal_dir + "/" + file_path, + db_options_.wal_dir, false); + if (!s.ok()) { + ROCKS_LOG_WARN(db_options_.info_log, "Unable to delete file: %s: %s", + file_path.c_str(), s.ToString().c_str()); + continue; + } else { + MutexLock l(&read_first_record_cache_mutex_); + read_first_record_cache_.erase(archived_logs[i]->LogNumber()); + } + } +} + +void WalManager::ArchiveWALFile(const std::string& fname, uint64_t number) { + auto archived_log_name = ArchivedLogFileName(db_options_.wal_dir, number); + // The sync point below is used in (DBTest,TransactionLogIteratorRace) + TEST_SYNC_POINT("WalManager::PurgeObsoleteFiles:1"); + Status s = env_->RenameFile(fname, archived_log_name); + // The sync point below is used in (DBTest,TransactionLogIteratorRace) + TEST_SYNC_POINT("WalManager::PurgeObsoleteFiles:2"); + ROCKS_LOG_INFO(db_options_.info_log, "Move log file %s to %s -- %s\n", + fname.c_str(), archived_log_name.c_str(), + s.ToString().c_str()); +} + +namespace { +struct CompareLogByPointer { + bool operator()(const std::unique_ptr<LogFile>& a, + const std::unique_ptr<LogFile>& b) { + LogFileImpl* a_impl = static_cast_with_check<LogFileImpl, LogFile>(a.get()); + LogFileImpl* b_impl = static_cast_with_check<LogFileImpl, LogFile>(b.get()); + return *a_impl < *b_impl; + } +}; +} + +Status WalManager::GetSortedWalsOfType(const std::string& path, + VectorLogPtr& log_files, + WalFileType log_type) { + std::vector<std::string> all_files; + const Status status = env_->GetChildren(path, &all_files); + if (!status.ok()) { + return status; + } + log_files.reserve(all_files.size()); + for (const auto& f : all_files) { + uint64_t number; + FileType type; + if (ParseFileName(f, &number, &type) && type == kLogFile) { + SequenceNumber sequence; + Status s = ReadFirstRecord(log_type, number, &sequence); + if (!s.ok()) { + return s; + } + if (sequence == 0) { + // empty file + continue; + } + + // Reproduce the race condition where a log file is moved + // to archived dir, between these two sync points, used in + // (DBTest,TransactionLogIteratorRace) + TEST_SYNC_POINT("WalManager::GetSortedWalsOfType:1"); + TEST_SYNC_POINT("WalManager::GetSortedWalsOfType:2"); + + uint64_t size_bytes; + s = env_->GetFileSize(LogFileName(path, number), &size_bytes); + // re-try in case the alive log file has been moved to archive. + std::string archived_file = ArchivedLogFileName(path, number); + if (!s.ok() && log_type == kAliveLogFile && + env_->FileExists(archived_file).ok()) { + s = env_->GetFileSize(archived_file, &size_bytes); + if (!s.ok() && env_->FileExists(archived_file).IsNotFound()) { + // oops, the file just got deleted from archived dir! move on + s = Status::OK(); + continue; + } + } + if (!s.ok()) { + return s; + } + + log_files.push_back(std::unique_ptr<LogFile>( + new LogFileImpl(number, log_type, sequence, size_bytes))); + } + } + CompareLogByPointer compare_log_files; + std::sort(log_files.begin(), log_files.end(), compare_log_files); + return status; +} + +Status WalManager::RetainProbableWalFiles(VectorLogPtr& all_logs, + const SequenceNumber target) { + int64_t start = 0; // signed to avoid overflow when target is < first file. + int64_t end = static_cast<int64_t>(all_logs.size()) - 1; + // Binary Search. avoid opening all files. + while (end >= start) { + int64_t mid = start + (end - start) / 2; // Avoid overflow. + SequenceNumber current_seq_num = all_logs.at(static_cast<size_t>(mid))->StartSequence(); + if (current_seq_num == target) { + end = mid; + break; + } else if (current_seq_num < target) { + start = mid + 1; + } else { + end = mid - 1; + } + } + // end could be -ve. + size_t start_index = static_cast<size_t>(std::max(static_cast<int64_t>(0), end)); + // The last wal file is always included + all_logs.erase(all_logs.begin(), all_logs.begin() + start_index); + return Status::OK(); +} + +Status WalManager::ReadFirstRecord(const WalFileType type, + const uint64_t number, + SequenceNumber* sequence) { + *sequence = 0; + if (type != kAliveLogFile && type != kArchivedLogFile) { + ROCKS_LOG_ERROR(db_options_.info_log, "[WalManger] Unknown file type %s", + ToString(type).c_str()); + return Status::NotSupported( + "File Type Not Known " + ToString(type)); + } + { + MutexLock l(&read_first_record_cache_mutex_); + auto itr = read_first_record_cache_.find(number); + if (itr != read_first_record_cache_.end()) { + *sequence = itr->second; + return Status::OK(); + } + } + Status s; + if (type == kAliveLogFile) { + std::string fname = LogFileName(db_options_.wal_dir, number); + s = ReadFirstLine(fname, number, sequence); + if (env_->FileExists(fname).ok() && !s.ok()) { + // return any error that is not caused by non-existing file + return s; + } + } + + if (type == kArchivedLogFile || !s.ok()) { + // check if the file got moved to archive. + std::string archived_file = + ArchivedLogFileName(db_options_.wal_dir, number); + s = ReadFirstLine(archived_file, number, sequence); + // maybe the file was deleted from archive dir. If that's the case, return + // Status::OK(). The caller with identify this as empty file because + // *sequence == 0 + if (!s.ok() && env_->FileExists(archived_file).IsNotFound()) { + return Status::OK(); + } + } + + if (s.ok() && *sequence != 0) { + MutexLock l(&read_first_record_cache_mutex_); + read_first_record_cache_.insert({number, *sequence}); + } + return s; +} + +// the function returns status.ok() and sequence == 0 if the file exists, but is +// empty +Status WalManager::ReadFirstLine(const std::string& fname, + const uint64_t number, + SequenceNumber* sequence) { + struct LogReporter : public log::Reader::Reporter { + Env* env; + Logger* info_log; + const char* fname; + + Status* status; + bool ignore_error; // true if db_options_.paranoid_checks==false + void Corruption(size_t bytes, const Status& s) override { + ROCKS_LOG_WARN(info_log, "[WalManager] %s%s: dropping %d bytes; %s", + (this->ignore_error ? "(ignoring error) " : ""), fname, + static_cast<int>(bytes), s.ToString().c_str()); + if (this->status->ok()) { + // only keep the first error + *this->status = s; + } + } + }; + + std::unique_ptr<SequentialFile> file; + Status status = env_->NewSequentialFile( + fname, &file, env_->OptimizeForLogRead(env_options_)); + std::unique_ptr<SequentialFileReader> file_reader( + new SequentialFileReader(std::move(file), fname)); + + if (!status.ok()) { + return status; + } + + LogReporter reporter; + reporter.env = env_; + reporter.info_log = db_options_.info_log.get(); + reporter.fname = fname.c_str(); + reporter.status = &status; + reporter.ignore_error = !db_options_.paranoid_checks; + log::Reader reader(db_options_.info_log, std::move(file_reader), &reporter, + true /*checksum*/, number); + std::string scratch; + Slice record; + + if (reader.ReadRecord(&record, &scratch) && + (status.ok() || !db_options_.paranoid_checks)) { + if (record.size() < WriteBatchInternal::kHeader) { + reporter.Corruption(record.size(), + Status::Corruption("log record too small")); + // TODO read record's till the first no corrupt entry? + } else { + WriteBatch batch; + WriteBatchInternal::SetContents(&batch, record); + *sequence = WriteBatchInternal::Sequence(&batch); + return Status::OK(); + } + } + + // ReadRecord returns false on EOF, which means that the log file is empty. we + // return status.ok() in that case and set sequence number to 0 + *sequence = 0; + return status; +} + +#endif // ROCKSDB_LITE +} // namespace rocksdb |