// 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 #include #include #include "db/builder.h" #include "db/db_impl/db_impl.h" #include "db/error_handler.h" #include "db/event_helpers.h" #include "file/sst_file_manager_impl.h" #include "logging/logging.h" #include "monitoring/iostats_context_imp.h" #include "monitoring/perf_context_imp.h" #include "monitoring/thread_status_updater.h" #include "monitoring/thread_status_util.h" #include "test_util/sync_point.h" #include "util/cast_util.h" #include "util/concurrent_task_limiter_impl.h" namespace ROCKSDB_NAMESPACE { bool DBImpl::EnoughRoomForCompaction( ColumnFamilyData* cfd, const std::vector& inputs, bool* sfm_reserved_compact_space, LogBuffer* log_buffer) { // Check if we have enough room to do the compaction bool enough_room = true; auto sfm = static_cast( immutable_db_options_.sst_file_manager.get()); if (sfm) { // Pass the current bg_error_ to SFM so it can decide what checks to // perform. If this DB instance hasn't seen any error yet, the SFM can be // optimistic and not do disk space checks Status bg_error = error_handler_.GetBGError(); enough_room = sfm->EnoughRoomForCompaction(cfd, inputs, bg_error); bg_error.PermitUncheckedError(); // bg_error is just a copy of the Status // from the error_handler_ if (enough_room) { *sfm_reserved_compact_space = true; } } if (!enough_room) { // Just in case tests want to change the value of enough_room TEST_SYNC_POINT_CALLBACK( "DBImpl::BackgroundCompaction():CancelledCompaction", &enough_room); ROCKS_LOG_BUFFER(log_buffer, "Cancelled compaction because not enough room"); RecordTick(stats_, COMPACTION_CANCELLED, 1); } return enough_room; } bool DBImpl::RequestCompactionToken(ColumnFamilyData* cfd, bool force, std::unique_ptr* token, LogBuffer* log_buffer) { assert(*token == nullptr); auto limiter = static_cast( cfd->ioptions()->compaction_thread_limiter.get()); if (limiter == nullptr) { return true; } *token = limiter->GetToken(force); if (*token != nullptr) { ROCKS_LOG_BUFFER(log_buffer, "Thread limiter [%s] increase [%s] compaction task, " "force: %s, tasks after: %d", limiter->GetName().c_str(), cfd->GetName().c_str(), force ? "true" : "false", limiter->GetOutstandingTask()); return true; } return false; } IOStatus DBImpl::SyncClosedLogs(JobContext* job_context, VersionEdit* synced_wals) { TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Start"); InstrumentedMutexLock l(&log_write_mutex_); autovector logs_to_sync; uint64_t current_log_number = logfile_number_; while (logs_.front().number < current_log_number && logs_.front().IsSyncing()) { log_sync_cv_.Wait(); } for (auto it = logs_.begin(); it != logs_.end() && it->number < current_log_number; ++it) { auto& log = *it; log.PrepareForSync(); logs_to_sync.push_back(log.writer); } IOStatus io_s; if (!logs_to_sync.empty()) { log_write_mutex_.Unlock(); assert(job_context); for (log::Writer* log : logs_to_sync) { ROCKS_LOG_INFO(immutable_db_options_.info_log, "[JOB %d] Syncing log #%" PRIu64, job_context->job_id, log->get_log_number()); if (error_handler_.IsRecoveryInProgress()) { log->file()->reset_seen_error(); } io_s = log->file()->Sync(immutable_db_options_.use_fsync); if (!io_s.ok()) { break; } if (immutable_db_options_.recycle_log_file_num > 0) { if (error_handler_.IsRecoveryInProgress()) { log->file()->reset_seen_error(); } io_s = log->Close(); if (!io_s.ok()) { break; } } } if (io_s.ok()) { io_s = directories_.GetWalDir()->FsyncWithDirOptions( IOOptions(), nullptr, DirFsyncOptions(DirFsyncOptions::FsyncReason::kNewFileSynced)); } TEST_SYNC_POINT_CALLBACK("DBImpl::SyncClosedLogs:BeforeReLock", /*arg=*/nullptr); log_write_mutex_.Lock(); // "number <= current_log_number - 1" is equivalent to // "number < current_log_number". if (io_s.ok()) { MarkLogsSynced(current_log_number - 1, true, synced_wals); } else { MarkLogsNotSynced(current_log_number - 1); } if (!io_s.ok()) { TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Failed"); return io_s; } } TEST_SYNC_POINT("DBImpl::SyncClosedLogs:end"); return io_s; } Status DBImpl::FlushMemTableToOutputFile( ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options, bool* made_progress, JobContext* job_context, FlushReason flush_reason, SuperVersionContext* superversion_context, std::vector& snapshot_seqs, SequenceNumber earliest_write_conflict_snapshot, SnapshotChecker* snapshot_checker, LogBuffer* log_buffer, Env::Priority thread_pri) { mutex_.AssertHeld(); assert(cfd); assert(cfd->imm()); assert(cfd->imm()->NumNotFlushed() != 0); assert(cfd->imm()->IsFlushPending()); assert(versions_); assert(versions_->GetColumnFamilySet()); // If there are more than one column families, we need to make sure that // all the log files except the most recent one are synced. Otherwise if // the host crashes after flushing and before WAL is persistent, the // flushed SST may contain data from write batches whose updates to // other (unflushed) column families are missing. const bool needs_to_sync_closed_wals = logfile_number_ > 0 && versions_->GetColumnFamilySet()->NumberOfColumnFamilies() > 1; // If needs_to_sync_closed_wals is true, we need to record the current // maximum memtable ID of this column family so that a later PickMemtables() // call will not pick memtables whose IDs are higher. This is due to the fact // that SyncClosedLogs() may release the db mutex, and memtable switch can // happen for this column family in the meantime. The newly created memtables // have their data backed by unsynced WALs, thus they cannot be included in // this flush job. // Another reason why we must record the current maximum memtable ID of this // column family: SyncClosedLogs() may release db mutex, thus it's possible // for application to continue to insert into memtables increasing db's // sequence number. The application may take a snapshot, but this snapshot is // not included in `snapshot_seqs` which will be passed to flush job because // `snapshot_seqs` has already been computed before this function starts. // Recording the max memtable ID ensures that the flush job does not flush // a memtable without knowing such snapshot(s). uint64_t max_memtable_id = needs_to_sync_closed_wals ? cfd->imm()->GetLatestMemTableID() : std::numeric_limits::max(); // If needs_to_sync_closed_wals is false, then the flush job will pick ALL // existing memtables of the column family when PickMemTable() is called // later. Although we won't call SyncClosedLogs() in this case, we may still // call the callbacks of the listeners, i.e. NotifyOnFlushBegin() which also // releases and re-acquires the db mutex. In the meantime, the application // can still insert into the memtables and increase the db's sequence number. // The application can take a snapshot, hoping that the latest visible state // to this snapshto is preserved. This is hard to guarantee since db mutex // not held. This newly-created snapshot is not included in `snapshot_seqs` // and the flush job is unaware of its presence. Consequently, the flush job // may drop certain keys when generating the L0, causing incorrect data to be // returned for snapshot read using this snapshot. // To address this, we make sure NotifyOnFlushBegin() executes after memtable // picking so that no new snapshot can be taken between the two functions. FlushJob flush_job( dbname_, cfd, immutable_db_options_, mutable_cf_options, max_memtable_id, file_options_for_compaction_, versions_.get(), &mutex_, &shutting_down_, snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker, job_context, flush_reason, log_buffer, directories_.GetDbDir(), GetDataDir(cfd, 0U), GetCompressionFlush(*cfd->ioptions(), mutable_cf_options), stats_, &event_logger_, mutable_cf_options.report_bg_io_stats, true /* sync_output_directory */, true /* write_manifest */, thread_pri, io_tracer_, seqno_time_mapping_, db_id_, db_session_id_, cfd->GetFullHistoryTsLow(), &blob_callback_); FileMetaData file_meta; Status s; bool need_cancel = false; IOStatus log_io_s = IOStatus::OK(); if (needs_to_sync_closed_wals) { // SyncClosedLogs() may unlock and re-lock the log_write_mutex multiple // times. VersionEdit synced_wals; mutex_.Unlock(); log_io_s = SyncClosedLogs(job_context, &synced_wals); mutex_.Lock(); if (log_io_s.ok() && synced_wals.IsWalAddition()) { log_io_s = status_to_io_status(ApplyWALToManifest(&synced_wals)); TEST_SYNC_POINT_CALLBACK("DBImpl::FlushMemTableToOutputFile:CommitWal:1", nullptr); } if (!log_io_s.ok() && !log_io_s.IsShutdownInProgress() && !log_io_s.IsColumnFamilyDropped()) { error_handler_.SetBGError(log_io_s, BackgroundErrorReason::kFlush); } } else { TEST_SYNC_POINT("DBImpl::SyncClosedLogs:Skip"); } s = log_io_s; // If the log sync failed, we do not need to pick memtable. Otherwise, // num_flush_not_started_ needs to be rollback. TEST_SYNC_POINT("DBImpl::FlushMemTableToOutputFile:BeforePickMemtables"); if (s.ok()) { flush_job.PickMemTable(); need_cancel = true; } TEST_SYNC_POINT_CALLBACK( "DBImpl::FlushMemTableToOutputFile:AfterPickMemtables", &flush_job); // may temporarily unlock and lock the mutex. NotifyOnFlushBegin(cfd, &file_meta, mutable_cf_options, job_context->job_id, flush_reason); bool switched_to_mempurge = false; // Within flush_job.Run, rocksdb may call event listener to notify // file creation and deletion. // // Note that flush_job.Run will unlock and lock the db_mutex, // and EventListener callback will be called when the db_mutex // is unlocked by the current thread. if (s.ok()) { s = flush_job.Run(&logs_with_prep_tracker_, &file_meta, &switched_to_mempurge); need_cancel = false; } if (!s.ok() && need_cancel) { flush_job.Cancel(); } if (s.ok()) { InstallSuperVersionAndScheduleWork(cfd, superversion_context, mutable_cf_options); if (made_progress) { *made_progress = true; } const std::string& column_family_name = cfd->GetName(); Version* const current = cfd->current(); assert(current); const VersionStorageInfo* const storage_info = current->storage_info(); assert(storage_info); VersionStorageInfo::LevelSummaryStorage tmp; ROCKS_LOG_BUFFER(log_buffer, "[%s] Level summary: %s\n", column_family_name.c_str(), storage_info->LevelSummary(&tmp)); const auto& blob_files = storage_info->GetBlobFiles(); if (!blob_files.empty()) { assert(blob_files.front()); assert(blob_files.back()); ROCKS_LOG_BUFFER( log_buffer, "[%s] Blob file summary: head=%" PRIu64 ", tail=%" PRIu64 "\n", column_family_name.c_str(), blob_files.front()->GetBlobFileNumber(), blob_files.back()->GetBlobFileNumber()); } } if (!s.ok() && !s.IsShutdownInProgress() && !s.IsColumnFamilyDropped()) { if (log_io_s.ok()) { // Error while writing to MANIFEST. // In fact, versions_->io_status() can also be the result of renaming // CURRENT file. With current code, it's just difficult to tell. So just // be pessimistic and try write to a new MANIFEST. // TODO: distinguish between MANIFEST write and CURRENT renaming if (!versions_->io_status().ok()) { // If WAL sync is successful (either WAL size is 0 or there is no IO // error), all the Manifest write will be map to soft error. // TODO: kManifestWriteNoWAL and kFlushNoWAL are misleading. Refactor is // needed. error_handler_.SetBGError(s, BackgroundErrorReason::kManifestWriteNoWAL); } else { // If WAL sync is successful (either WAL size is 0 or there is no IO // error), all the other SST file write errors will be set as // kFlushNoWAL. error_handler_.SetBGError(s, BackgroundErrorReason::kFlushNoWAL); } } else { assert(s.code() == log_io_s.code() && s.subcode() == log_io_s.subcode()); Status new_bg_error = s; error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush); } } // If flush ran smoothly and no mempurge happened // install new SST file path. if (s.ok() && (!switched_to_mempurge)) { // may temporarily unlock and lock the mutex. NotifyOnFlushCompleted(cfd, mutable_cf_options, flush_job.GetCommittedFlushJobsInfo()); auto sfm = static_cast( immutable_db_options_.sst_file_manager.get()); if (sfm) { // Notify sst_file_manager that a new file was added std::string file_path = MakeTableFileName( cfd->ioptions()->cf_paths[0].path, file_meta.fd.GetNumber()); // TODO (PR7798). We should only add the file to the FileManager if it // exists. Otherwise, some tests may fail. Ignore the error in the // interim. sfm->OnAddFile(file_path).PermitUncheckedError(); if (sfm->IsMaxAllowedSpaceReached()) { Status new_bg_error = Status::SpaceLimit("Max allowed space was reached"); TEST_SYNC_POINT_CALLBACK( "DBImpl::FlushMemTableToOutputFile:MaxAllowedSpaceReached", &new_bg_error); error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush); } } } TEST_SYNC_POINT("DBImpl::FlushMemTableToOutputFile:Finish"); return s; } Status DBImpl::FlushMemTablesToOutputFiles( const autovector& bg_flush_args, bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri) { if (immutable_db_options_.atomic_flush) { return AtomicFlushMemTablesToOutputFiles( bg_flush_args, made_progress, job_context, log_buffer, thread_pri); } assert(bg_flush_args.size() == 1); std::vector snapshot_seqs; SequenceNumber earliest_write_conflict_snapshot; SnapshotChecker* snapshot_checker; GetSnapshotContext(job_context, &snapshot_seqs, &earliest_write_conflict_snapshot, &snapshot_checker); const auto& bg_flush_arg = bg_flush_args[0]; ColumnFamilyData* cfd = bg_flush_arg.cfd_; // intentional infrequent copy for each flush MutableCFOptions mutable_cf_options_copy = *cfd->GetLatestMutableCFOptions(); SuperVersionContext* superversion_context = bg_flush_arg.superversion_context_; FlushReason flush_reason = bg_flush_arg.flush_reason_; Status s = FlushMemTableToOutputFile( cfd, mutable_cf_options_copy, made_progress, job_context, flush_reason, superversion_context, snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker, log_buffer, thread_pri); return s; } /* * Atomically flushes multiple column families. * * For each column family, all memtables with ID smaller than or equal to the * ID specified in bg_flush_args will be flushed. Only after all column * families finish flush will this function commit to MANIFEST. If any of the * column families are not flushed successfully, this function does not have * any side-effect on the state of the database. */ Status DBImpl::AtomicFlushMemTablesToOutputFiles( const autovector& bg_flush_args, bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri) { mutex_.AssertHeld(); autovector cfds; for (const auto& arg : bg_flush_args) { cfds.emplace_back(arg.cfd_); } #ifndef NDEBUG for (const auto cfd : cfds) { assert(cfd->imm()->NumNotFlushed() != 0); assert(cfd->imm()->IsFlushPending()); } for (const auto& bg_flush_arg : bg_flush_args) { assert(bg_flush_arg.flush_reason_ == bg_flush_args[0].flush_reason_); } #endif /* !NDEBUG */ std::vector snapshot_seqs; SequenceNumber earliest_write_conflict_snapshot; SnapshotChecker* snapshot_checker; GetSnapshotContext(job_context, &snapshot_seqs, &earliest_write_conflict_snapshot, &snapshot_checker); autovector distinct_output_dirs; autovector distinct_output_dir_paths; std::vector> jobs; std::vector all_mutable_cf_options; int num_cfs = static_cast(cfds.size()); all_mutable_cf_options.reserve(num_cfs); for (int i = 0; i < num_cfs; ++i) { auto cfd = cfds[i]; FSDirectory* data_dir = GetDataDir(cfd, 0U); const std::string& curr_path = cfd->ioptions()->cf_paths[0].path; // Add to distinct output directories if eligible. Use linear search. Since // the number of elements in the vector is not large, performance should be // tolerable. bool found = false; for (const auto& path : distinct_output_dir_paths) { if (path == curr_path) { found = true; break; } } if (!found) { distinct_output_dir_paths.emplace_back(curr_path); distinct_output_dirs.emplace_back(data_dir); } all_mutable_cf_options.emplace_back(*cfd->GetLatestMutableCFOptions()); const MutableCFOptions& mutable_cf_options = all_mutable_cf_options.back(); uint64_t max_memtable_id = bg_flush_args[i].max_memtable_id_; FlushReason flush_reason = bg_flush_args[i].flush_reason_; jobs.emplace_back(new FlushJob( dbname_, cfd, immutable_db_options_, mutable_cf_options, max_memtable_id, file_options_for_compaction_, versions_.get(), &mutex_, &shutting_down_, snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker, job_context, flush_reason, log_buffer, directories_.GetDbDir(), data_dir, GetCompressionFlush(*cfd->ioptions(), mutable_cf_options), stats_, &event_logger_, mutable_cf_options.report_bg_io_stats, false /* sync_output_directory */, false /* write_manifest */, thread_pri, io_tracer_, seqno_time_mapping_, db_id_, db_session_id_, cfd->GetFullHistoryTsLow(), &blob_callback_)); } std::vector file_meta(num_cfs); // Use of deque because vector // is specific and doesn't allow &v[i]. std::deque switched_to_mempurge(num_cfs, false); Status s; IOStatus log_io_s = IOStatus::OK(); assert(num_cfs == static_cast(jobs.size())); for (int i = 0; i != num_cfs; ++i) { const MutableCFOptions& mutable_cf_options = all_mutable_cf_options.at(i); // may temporarily unlock and lock the mutex. FlushReason flush_reason = bg_flush_args[i].flush_reason_; NotifyOnFlushBegin(cfds[i], &file_meta[i], mutable_cf_options, job_context->job_id, flush_reason); } if (logfile_number_ > 0) { // TODO (yanqin) investigate whether we should sync the closed logs for // single column family case. VersionEdit synced_wals; mutex_.Unlock(); log_io_s = SyncClosedLogs(job_context, &synced_wals); mutex_.Lock(); if (log_io_s.ok() && synced_wals.IsWalAddition()) { log_io_s = status_to_io_status(ApplyWALToManifest(&synced_wals)); } if (!log_io_s.ok() && !log_io_s.IsShutdownInProgress() && !log_io_s.IsColumnFamilyDropped()) { if (total_log_size_ > 0) { error_handler_.SetBGError(log_io_s, BackgroundErrorReason::kFlush); } else { // If the WAL is empty, we use different error reason error_handler_.SetBGError(log_io_s, BackgroundErrorReason::kFlushNoWAL); } } } s = log_io_s; // exec_status stores the execution status of flush_jobs as // autovector> exec_status; std::vector pick_status; for (int i = 0; i != num_cfs; ++i) { // Initially all jobs are not executed, with status OK. exec_status.emplace_back(false, Status::OK()); pick_status.push_back(false); } if (s.ok()) { for (int i = 0; i != num_cfs; ++i) { jobs[i]->PickMemTable(); pick_status[i] = true; } } if (s.ok()) { assert(switched_to_mempurge.size() == static_cast(num_cfs)); // TODO (yanqin): parallelize jobs with threads. for (int i = 1; i != num_cfs; ++i) { exec_status[i].second = jobs[i]->Run(&logs_with_prep_tracker_, &file_meta[i], &(switched_to_mempurge.at(i))); exec_status[i].first = true; } if (num_cfs > 1) { TEST_SYNC_POINT( "DBImpl::AtomicFlushMemTablesToOutputFiles:SomeFlushJobsComplete:1"); TEST_SYNC_POINT( "DBImpl::AtomicFlushMemTablesToOutputFiles:SomeFlushJobsComplete:2"); } assert(exec_status.size() > 0); assert(!file_meta.empty()); exec_status[0].second = jobs[0]->Run( &logs_with_prep_tracker_, file_meta.data() /* &file_meta[0] */, switched_to_mempurge.empty() ? nullptr : &(switched_to_mempurge.at(0))); exec_status[0].first = true; Status error_status; for (const auto& e : exec_status) { if (!e.second.ok()) { s = e.second; if (!e.second.IsShutdownInProgress() && !e.second.IsColumnFamilyDropped()) { // If a flush job did not return OK, and the CF is not dropped, and // the DB is not shutting down, then we have to return this result to // caller later. error_status = e.second; } } } s = error_status.ok() ? s : error_status; } if (s.IsColumnFamilyDropped()) { s = Status::OK(); } if (s.ok() || s.IsShutdownInProgress()) { // Sync on all distinct output directories. for (auto dir : distinct_output_dirs) { if (dir != nullptr) { Status error_status = dir->FsyncWithDirOptions( IOOptions(), nullptr, DirFsyncOptions(DirFsyncOptions::FsyncReason::kNewFileSynced)); if (!error_status.ok()) { s = error_status; break; } } } } else { // Need to undo atomic flush if something went wrong, i.e. s is not OK and // it is not because of CF drop. // Have to cancel the flush jobs that have NOT executed because we need to // unref the versions. for (int i = 0; i != num_cfs; ++i) { if (pick_status[i] && !exec_status[i].first) { jobs[i]->Cancel(); } } for (int i = 0; i != num_cfs; ++i) { if (exec_status[i].second.ok() && exec_status[i].first) { auto& mems = jobs[i]->GetMemTables(); cfds[i]->imm()->RollbackMemtableFlush(mems, file_meta[i].fd.GetNumber()); } } } if (s.ok()) { const auto wait_to_install_func = [&]() -> std::pair { if (!versions_->io_status().ok()) { // Something went wrong elsewhere, we cannot count on waiting for our // turn to write/sync to MANIFEST or CURRENT. Just return. return std::make_pair(versions_->io_status(), false); } else if (shutting_down_.load(std::memory_order_acquire)) { return std::make_pair(Status::ShutdownInProgress(), false); } bool ready = true; for (size_t i = 0; i != cfds.size(); ++i) { const auto& mems = jobs[i]->GetMemTables(); if (cfds[i]->IsDropped()) { // If the column family is dropped, then do not wait. continue; } else if (!mems.empty() && cfds[i]->imm()->GetEarliestMemTableID() < mems[0]->GetID()) { // If a flush job needs to install the flush result for mems and // mems[0] is not the earliest memtable, it means another thread must // be installing flush results for the same column family, then the // current thread needs to wait. ready = false; break; } else if (mems.empty() && cfds[i]->imm()->GetEarliestMemTableID() <= bg_flush_args[i].max_memtable_id_) { // If a flush job does not need to install flush results, then it has // to wait until all memtables up to max_memtable_id_ (inclusive) are // installed. ready = false; break; } } return std::make_pair(Status::OK(), !ready); }; bool resuming_from_bg_err = error_handler_.IsDBStopped() || (bg_flush_args[0].flush_reason_ == FlushReason::kErrorRecovery || bg_flush_args[0].flush_reason_ == FlushReason::kErrorRecoveryRetryFlush); while ((!resuming_from_bg_err || error_handler_.GetRecoveryError().ok())) { std::pair res = wait_to_install_func(); TEST_SYNC_POINT_CALLBACK( "DBImpl::AtomicFlushMemTablesToOutputFiles:WaitToCommit", &res); if (!res.first.ok()) { s = res.first; break; } else if (!res.second) { break; } atomic_flush_install_cv_.Wait(); resuming_from_bg_err = error_handler_.IsDBStopped() || (bg_flush_args[0].flush_reason_ == FlushReason::kErrorRecovery || bg_flush_args[0].flush_reason_ == FlushReason::kErrorRecoveryRetryFlush); } if (!resuming_from_bg_err) { // If not resuming from bg err, then we determine future action based on // whether we hit background error. if (s.ok()) { s = error_handler_.GetBGError(); } } else if (s.ok()) { // If resuming from bg err, we still rely on wait_to_install_func()'s // result to determine future action. If wait_to_install_func() returns // non-ok already, then we should not proceed to flush result // installation. s = error_handler_.GetRecoveryError(); } } if (s.ok()) { autovector tmp_cfds; autovector*> mems_list; autovector mutable_cf_options_list; autovector tmp_file_meta; autovector>*> committed_flush_jobs_info; for (int i = 0; i != num_cfs; ++i) { const auto& mems = jobs[i]->GetMemTables(); if (!cfds[i]->IsDropped() && !mems.empty()) { tmp_cfds.emplace_back(cfds[i]); mems_list.emplace_back(&mems); mutable_cf_options_list.emplace_back(&all_mutable_cf_options[i]); tmp_file_meta.emplace_back(&file_meta[i]); committed_flush_jobs_info.emplace_back( jobs[i]->GetCommittedFlushJobsInfo()); } } s = InstallMemtableAtomicFlushResults( nullptr /* imm_lists */, tmp_cfds, mutable_cf_options_list, mems_list, versions_.get(), &logs_with_prep_tracker_, &mutex_, tmp_file_meta, committed_flush_jobs_info, &job_context->memtables_to_free, directories_.GetDbDir(), log_buffer); } if (s.ok()) { assert(num_cfs == static_cast(job_context->superversion_contexts.size())); for (int i = 0; i != num_cfs; ++i) { assert(cfds[i]); if (cfds[i]->IsDropped()) { continue; } InstallSuperVersionAndScheduleWork(cfds[i], &job_context->superversion_contexts[i], all_mutable_cf_options[i]); const std::string& column_family_name = cfds[i]->GetName(); Version* const current = cfds[i]->current(); assert(current); const VersionStorageInfo* const storage_info = current->storage_info(); assert(storage_info); VersionStorageInfo::LevelSummaryStorage tmp; ROCKS_LOG_BUFFER(log_buffer, "[%s] Level summary: %s\n", column_family_name.c_str(), storage_info->LevelSummary(&tmp)); const auto& blob_files = storage_info->GetBlobFiles(); if (!blob_files.empty()) { assert(blob_files.front()); assert(blob_files.back()); ROCKS_LOG_BUFFER( log_buffer, "[%s] Blob file summary: head=%" PRIu64 ", tail=%" PRIu64 "\n", column_family_name.c_str(), blob_files.front()->GetBlobFileNumber(), blob_files.back()->GetBlobFileNumber()); } } if (made_progress) { *made_progress = true; } auto sfm = static_cast( immutable_db_options_.sst_file_manager.get()); assert(all_mutable_cf_options.size() == static_cast(num_cfs)); for (int i = 0; s.ok() && i != num_cfs; ++i) { // If mempurge happened instead of Flush, // no NotifyOnFlushCompleted call (no SST file created). if (switched_to_mempurge[i]) { continue; } if (cfds[i]->IsDropped()) { continue; } NotifyOnFlushCompleted(cfds[i], all_mutable_cf_options[i], jobs[i]->GetCommittedFlushJobsInfo()); if (sfm) { std::string file_path = MakeTableFileName( cfds[i]->ioptions()->cf_paths[0].path, file_meta[i].fd.GetNumber()); // TODO (PR7798). We should only add the file to the FileManager if it // exists. Otherwise, some tests may fail. Ignore the error in the // interim. sfm->OnAddFile(file_path).PermitUncheckedError(); if (sfm->IsMaxAllowedSpaceReached() && error_handler_.GetBGError().ok()) { Status new_bg_error = Status::SpaceLimit("Max allowed space was reached"); error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush); } } } } // Need to undo atomic flush if something went wrong, i.e. s is not OK and // it is not because of CF drop. if (!s.ok() && !s.IsColumnFamilyDropped()) { if (log_io_s.ok()) { // Error while writing to MANIFEST. // In fact, versions_->io_status() can also be the result of renaming // CURRENT file. With current code, it's just difficult to tell. So just // be pessimistic and try write to a new MANIFEST. // TODO: distinguish between MANIFEST write and CURRENT renaming if (!versions_->io_status().ok()) { // If WAL sync is successful (either WAL size is 0 or there is no IO // error), all the Manifest write will be map to soft error. // TODO: kManifestWriteNoWAL and kFlushNoWAL are misleading. Refactor // is needed. error_handler_.SetBGError(s, BackgroundErrorReason::kManifestWriteNoWAL); } else { // If WAL sync is successful (either WAL size is 0 or there is no IO // error), all the other SST file write errors will be set as // kFlushNoWAL. error_handler_.SetBGError(s, BackgroundErrorReason::kFlushNoWAL); } } else { assert(s.code() == log_io_s.code() && s.subcode() == log_io_s.subcode()); Status new_bg_error = s; error_handler_.SetBGError(new_bg_error, BackgroundErrorReason::kFlush); } } return s; } void DBImpl::NotifyOnFlushBegin(ColumnFamilyData* cfd, FileMetaData* file_meta, const MutableCFOptions& mutable_cf_options, int job_id, FlushReason flush_reason) { if (immutable_db_options_.listeners.size() == 0U) { return; } mutex_.AssertHeld(); if (shutting_down_.load(std::memory_order_acquire)) { return; } bool triggered_writes_slowdown = (cfd->current()->storage_info()->NumLevelFiles(0) >= mutable_cf_options.level0_slowdown_writes_trigger); bool triggered_writes_stop = (cfd->current()->storage_info()->NumLevelFiles(0) >= mutable_cf_options.level0_stop_writes_trigger); // release lock while notifying events mutex_.Unlock(); { FlushJobInfo info{}; info.cf_id = cfd->GetID(); info.cf_name = cfd->GetName(); // TODO(yhchiang): make db_paths dynamic in case flush does not // go to L0 in the future. const uint64_t file_number = file_meta->fd.GetNumber(); info.file_path = MakeTableFileName(cfd->ioptions()->cf_paths[0].path, file_number); info.file_number = file_number; info.thread_id = env_->GetThreadID(); info.job_id = job_id; info.triggered_writes_slowdown = triggered_writes_slowdown; info.triggered_writes_stop = triggered_writes_stop; info.smallest_seqno = file_meta->fd.smallest_seqno; info.largest_seqno = file_meta->fd.largest_seqno; info.flush_reason = flush_reason; for (auto listener : immutable_db_options_.listeners) { listener->OnFlushBegin(this, info); } } mutex_.Lock(); // no need to signal bg_cv_ as it will be signaled at the end of the // flush process. } void DBImpl::NotifyOnFlushCompleted( ColumnFamilyData* cfd, const MutableCFOptions& mutable_cf_options, std::list>* flush_jobs_info) { assert(flush_jobs_info != nullptr); if (immutable_db_options_.listeners.size() == 0U) { return; } mutex_.AssertHeld(); if (shutting_down_.load(std::memory_order_acquire)) { return; } bool triggered_writes_slowdown = (cfd->current()->storage_info()->NumLevelFiles(0) >= mutable_cf_options.level0_slowdown_writes_trigger); bool triggered_writes_stop = (cfd->current()->storage_info()->NumLevelFiles(0) >= mutable_cf_options.level0_stop_writes_trigger); // release lock while notifying events mutex_.Unlock(); { for (auto& info : *flush_jobs_info) { info->triggered_writes_slowdown = triggered_writes_slowdown; info->triggered_writes_stop = triggered_writes_stop; for (auto listener : immutable_db_options_.listeners) { listener->OnFlushCompleted(this, *info); } TEST_SYNC_POINT( "DBImpl::NotifyOnFlushCompleted::PostAllOnFlushCompleted"); } flush_jobs_info->clear(); } mutex_.Lock(); // no need to signal bg_cv_ as it will be signaled at the end of the // flush process. } Status DBImpl::CompactRange(const CompactRangeOptions& options, ColumnFamilyHandle* column_family, const Slice* begin_without_ts, const Slice* end_without_ts) { if (manual_compaction_paused_.load(std::memory_order_acquire) > 0) { return Status::Incomplete(Status::SubCode::kManualCompactionPaused); } if (options.canceled && options.canceled->load(std::memory_order_acquire)) { return Status::Incomplete(Status::SubCode::kManualCompactionPaused); } const Comparator* const ucmp = column_family->GetComparator(); assert(ucmp); size_t ts_sz = ucmp->timestamp_size(); if (ts_sz == 0) { return CompactRangeInternal(options, column_family, begin_without_ts, end_without_ts, "" /*trim_ts*/); } std::string begin_str; std::string end_str; // CompactRange compact all keys: [begin, end] inclusively. Add maximum // timestamp to include all `begin` keys, and add minimal timestamp to include // all `end` keys. if (begin_without_ts != nullptr) { AppendKeyWithMaxTimestamp(&begin_str, *begin_without_ts, ts_sz); } if (end_without_ts != nullptr) { AppendKeyWithMinTimestamp(&end_str, *end_without_ts, ts_sz); } Slice begin(begin_str); Slice end(end_str); Slice* begin_with_ts = begin_without_ts ? &begin : nullptr; Slice* end_with_ts = end_without_ts ? &end : nullptr; return CompactRangeInternal(options, column_family, begin_with_ts, end_with_ts, "" /*trim_ts*/); } Status DBImpl::IncreaseFullHistoryTsLow(ColumnFamilyHandle* column_family, std::string ts_low) { ColumnFamilyData* cfd = nullptr; if (column_family == nullptr) { cfd = default_cf_handle_->cfd(); } else { auto cfh = static_cast_with_check(column_family); assert(cfh != nullptr); cfd = cfh->cfd(); } assert(cfd != nullptr && cfd->user_comparator() != nullptr); if (cfd->user_comparator()->timestamp_size() == 0) { return Status::InvalidArgument( "Timestamp is not enabled in this column family"); } if (cfd->user_comparator()->timestamp_size() != ts_low.size()) { return Status::InvalidArgument("ts_low size mismatch"); } return IncreaseFullHistoryTsLowImpl(cfd, ts_low); } Status DBImpl::IncreaseFullHistoryTsLowImpl(ColumnFamilyData* cfd, std::string ts_low) { VersionEdit edit; edit.SetColumnFamily(cfd->GetID()); edit.SetFullHistoryTsLow(ts_low); TEST_SYNC_POINT_CALLBACK("DBImpl::IncreaseFullHistoryTsLowImpl:BeforeEdit", &edit); InstrumentedMutexLock l(&mutex_); std::string current_ts_low = cfd->GetFullHistoryTsLow(); const Comparator* ucmp = cfd->user_comparator(); assert(ucmp->timestamp_size() == ts_low.size() && !ts_low.empty()); if (!current_ts_low.empty() && ucmp->CompareTimestamp(ts_low, current_ts_low) < 0) { return Status::InvalidArgument("Cannot decrease full_history_ts_low"); } Status s = versions_->LogAndApply(cfd, *cfd->GetLatestMutableCFOptions(), &edit, &mutex_, directories_.GetDbDir()); if (!s.ok()) { return s; } current_ts_low = cfd->GetFullHistoryTsLow(); if (!current_ts_low.empty() && ucmp->CompareTimestamp(current_ts_low, ts_low) > 0) { std::stringstream oss; oss << "full_history_ts_low: " << Slice(current_ts_low).ToString(true) << " is set to be higher than the requested " "timestamp: " << Slice(ts_low).ToString(true) << std::endl; return Status::TryAgain(oss.str()); } return Status::OK(); } Status DBImpl::CompactRangeInternal(const CompactRangeOptions& options, ColumnFamilyHandle* column_family, const Slice* begin, const Slice* end, const std::string& trim_ts) { auto cfh = static_cast_with_check(column_family); auto cfd = cfh->cfd(); if (options.target_path_id >= cfd->ioptions()->cf_paths.size()) { return Status::InvalidArgument("Invalid target path ID"); } bool flush_needed = true; // Update full_history_ts_low if it's set if (options.full_history_ts_low != nullptr && !options.full_history_ts_low->empty()) { std::string ts_low = options.full_history_ts_low->ToString(); if (begin != nullptr || end != nullptr) { return Status::InvalidArgument( "Cannot specify compaction range with full_history_ts_low"); } Status s = IncreaseFullHistoryTsLowImpl(cfd, ts_low); if (!s.ok()) { LogFlush(immutable_db_options_.info_log); return s; } } Status s; if (begin != nullptr && end != nullptr) { // TODO(ajkr): We could also optimize away the flush in certain cases where // one/both sides of the interval are unbounded. But it requires more // changes to RangesOverlapWithMemtables. Range range(*begin, *end); SuperVersion* super_version = cfd->GetReferencedSuperVersion(this); s = cfd->RangesOverlapWithMemtables( {range}, super_version, immutable_db_options_.allow_data_in_errors, &flush_needed); CleanupSuperVersion(super_version); } if (s.ok() && flush_needed) { FlushOptions fo; fo.allow_write_stall = options.allow_write_stall; if (immutable_db_options_.atomic_flush) { s = AtomicFlushMemTables(fo, FlushReason::kManualCompaction); } else { s = FlushMemTable(cfd, fo, FlushReason::kManualCompaction); } if (!s.ok()) { LogFlush(immutable_db_options_.info_log); return s; } } constexpr int kInvalidLevel = -1; int final_output_level = kInvalidLevel; bool exclusive = options.exclusive_manual_compaction; if (cfd->ioptions()->compaction_style == kCompactionStyleUniversal && cfd->NumberLevels() > 1) { // Always compact all files together. final_output_level = cfd->NumberLevels() - 1; // if bottom most level is reserved if (immutable_db_options_.allow_ingest_behind) { final_output_level--; } s = RunManualCompaction(cfd, ColumnFamilyData::kCompactAllLevels, final_output_level, options, begin, end, exclusive, false, std::numeric_limits::max(), trim_ts); } else { int first_overlapped_level = kInvalidLevel; int max_overlapped_level = kInvalidLevel; { SuperVersion* super_version = cfd->GetReferencedSuperVersion(this); Version* current_version = super_version->current; // Might need to query the partitioner SstPartitionerFactory* partitioner_factory = current_version->cfd()->ioptions()->sst_partitioner_factory.get(); std::unique_ptr partitioner; if (partitioner_factory && begin != nullptr && end != nullptr) { SstPartitioner::Context context; context.is_full_compaction = false; context.is_manual_compaction = true; context.output_level = /*unknown*/ -1; // Small lies about compaction range context.smallest_user_key = *begin; context.largest_user_key = *end; partitioner = partitioner_factory->CreatePartitioner(context); } ReadOptions ro; ro.total_order_seek = true; bool overlap; for (int level = 0; level < current_version->storage_info()->num_non_empty_levels(); level++) { overlap = true; // Whether to look at specific keys within files for overlap with // compaction range, other than largest and smallest keys of the file // known in Version metadata. bool check_overlap_within_file = false; if (begin != nullptr && end != nullptr) { // Typically checking overlap within files in this case check_overlap_within_file = true; // WART: Not known why we don't check within file in one-sided bound // cases if (partitioner) { // Especially if the partitioner is new, the manual compaction // might be used to enforce the partitioning. Checking overlap // within files might miss cases where compaction is needed to // partition the files, as in this example: // * File has two keys "001" and "111" // * Compaction range is ["011", "101") // * Partition boundary at "100" // In cases like this, file-level overlap with the compaction // range is sufficient to force any partitioning that is needed // within the compaction range. // // But if there's no partitioning boundary within the compaction // range, we can be sure there's no need to fix partitioning // within that range, thus safe to check overlap within file. // // Use a hypothetical trivial move query to check for partition // boundary in range. (NOTE: in defiance of all conventions, // `begin` and `end` here are both INCLUSIVE bounds, which makes // this analogy to CanDoTrivialMove() accurate even when `end` is // the first key in a partition.) if (!partitioner->CanDoTrivialMove(*begin, *end)) { check_overlap_within_file = false; } } } if (check_overlap_within_file) { Status status = current_version->OverlapWithLevelIterator( ro, file_options_, *begin, *end, level, &overlap); if (!status.ok()) { check_overlap_within_file = false; } } if (!check_overlap_within_file) { overlap = current_version->storage_info()->OverlapInLevel(level, begin, end); } if (overlap) { if (first_overlapped_level == kInvalidLevel) { first_overlapped_level = level; } max_overlapped_level = level; } } CleanupSuperVersion(super_version); } if (s.ok() && first_overlapped_level != kInvalidLevel) { // max_file_num_to_ignore can be used to filter out newly created SST // files, useful for bottom level compaction in a manual compaction uint64_t max_file_num_to_ignore = std::numeric_limits::max(); uint64_t next_file_number = versions_->current_next_file_number(); final_output_level = max_overlapped_level; int output_level; for (int level = first_overlapped_level; level <= max_overlapped_level; level++) { bool disallow_trivial_move = false; // in case the compaction is universal or if we're compacting the // bottom-most level, the output level will be the same as input one. // level 0 can never be the bottommost level (i.e. if all files are in // level 0, we will compact to level 1) if (cfd->ioptions()->compaction_style == kCompactionStyleUniversal || cfd->ioptions()->compaction_style == kCompactionStyleFIFO) { output_level = level; } else if (level == max_overlapped_level && level > 0) { if (options.bottommost_level_compaction == BottommostLevelCompaction::kSkip) { // Skip bottommost level compaction continue; } else if (options.bottommost_level_compaction == BottommostLevelCompaction::kIfHaveCompactionFilter && cfd->ioptions()->compaction_filter == nullptr && cfd->ioptions()->compaction_filter_factory == nullptr) { // Skip bottommost level compaction since we don't have a compaction // filter continue; } output_level = level; // update max_file_num_to_ignore only for bottom level compaction // because data in newly compacted files in middle levels may still // need to be pushed down max_file_num_to_ignore = next_file_number; } else { output_level = level + 1; if (cfd->ioptions()->compaction_style == kCompactionStyleLevel && cfd->ioptions()->level_compaction_dynamic_level_bytes && level == 0) { output_level = ColumnFamilyData::kCompactToBaseLevel; } // if it's a BottommostLevel compaction and `kForce*` compaction is // set, disallow trivial move if (level == max_overlapped_level && (options.bottommost_level_compaction == BottommostLevelCompaction::kForce || options.bottommost_level_compaction == BottommostLevelCompaction::kForceOptimized)) { disallow_trivial_move = true; } } // trim_ts need real compaction to remove latest record if (!trim_ts.empty()) { disallow_trivial_move = true; } s = RunManualCompaction(cfd, level, output_level, options, begin, end, exclusive, disallow_trivial_move, max_file_num_to_ignore, trim_ts); if (!s.ok()) { break; } if (output_level == ColumnFamilyData::kCompactToBaseLevel) { final_output_level = cfd->NumberLevels() - 1; } else if (output_level > final_output_level) { final_output_level = output_level; } TEST_SYNC_POINT("DBImpl::RunManualCompaction()::1"); TEST_SYNC_POINT("DBImpl::RunManualCompaction()::2"); } } } if (!s.ok() || final_output_level == kInvalidLevel) { LogFlush(immutable_db_options_.info_log); return s; } if (options.change_level) { TEST_SYNC_POINT("DBImpl::CompactRange:BeforeRefit:1"); TEST_SYNC_POINT("DBImpl::CompactRange:BeforeRefit:2"); ROCKS_LOG_INFO(immutable_db_options_.info_log, "[RefitLevel] waiting for background threads to stop"); // TODO(hx235): remove `Enable/DisableManualCompaction` and // `Continue/PauseBackgroundWork` once we ensure registering RefitLevel()'s // range is sufficient (if not, what else is needed) for avoiding range // conflicts with other activities (e.g, compaction, flush) that are // currently avoided by `Enable/DisableManualCompaction` and // `Continue/PauseBackgroundWork`. DisableManualCompaction(); s = PauseBackgroundWork(); if (s.ok()) { TEST_SYNC_POINT("DBImpl::CompactRange:PreRefitLevel"); s = ReFitLevel(cfd, final_output_level, options.target_level); TEST_SYNC_POINT("DBImpl::CompactRange:PostRefitLevel"); // ContinueBackgroundWork always return Status::OK(). Status temp_s = ContinueBackgroundWork(); assert(temp_s.ok()); } EnableManualCompaction(); TEST_SYNC_POINT( "DBImpl::CompactRange:PostRefitLevel:ManualCompactionEnabled"); } LogFlush(immutable_db_options_.info_log); { InstrumentedMutexLock l(&mutex_); // an automatic compaction that has been scheduled might have been // preempted by the manual compactions. Need to schedule it back. MaybeScheduleFlushOrCompaction(); } return s; } Status DBImpl::CompactFiles(const CompactionOptions& compact_options, ColumnFamilyHandle* column_family, const std::vector& input_file_names, const int output_level, const int output_path_id, std::vector* const output_file_names, CompactionJobInfo* compaction_job_info) { if (column_family == nullptr) { return Status::InvalidArgument("ColumnFamilyHandle must be non-null."); } auto cfd = static_cast_with_check(column_family)->cfd(); assert(cfd); Status s; JobContext job_context(next_job_id_.fetch_add(1), true); LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, immutable_db_options_.info_log.get()); // Perform CompactFiles TEST_SYNC_POINT("TestCompactFiles::IngestExternalFile2"); TEST_SYNC_POINT_CALLBACK( "TestCompactFiles:PausingManualCompaction:3", reinterpret_cast( const_cast*>(&manual_compaction_paused_))); { InstrumentedMutexLock l(&mutex_); auto* current = cfd->current(); current->Ref(); s = CompactFilesImpl(compact_options, cfd, current, input_file_names, output_file_names, output_level, output_path_id, &job_context, &log_buffer, compaction_job_info); current->Unref(); } // Find and delete obsolete files { InstrumentedMutexLock l(&mutex_); // If !s.ok(), this means that Compaction failed. In that case, we want // to delete all obsolete files we might have created and we force // FindObsoleteFiles(). This is because job_context does not // catch all created files if compaction failed. FindObsoleteFiles(&job_context, !s.ok()); } // release the mutex // delete unnecessary files if any, this is done outside the mutex if (job_context.HaveSomethingToClean() || job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) { // Have to flush the info logs before bg_compaction_scheduled_-- // because if bg_flush_scheduled_ becomes 0 and the lock is // released, the deconstructor of DB can kick in and destroy all the // states of DB so info_log might not be available after that point. // It also applies to access other states that DB owns. log_buffer.FlushBufferToLog(); if (job_context.HaveSomethingToDelete()) { // no mutex is locked here. No need to Unlock() and Lock() here. PurgeObsoleteFiles(job_context); } job_context.Clean(); } return s; } Status DBImpl::CompactFilesImpl( const CompactionOptions& compact_options, ColumnFamilyData* cfd, Version* version, const std::vector& input_file_names, std::vector* const output_file_names, const int output_level, int output_path_id, JobContext* job_context, LogBuffer* log_buffer, CompactionJobInfo* compaction_job_info) { mutex_.AssertHeld(); if (shutting_down_.load(std::memory_order_acquire)) { return Status::ShutdownInProgress(); } if (manual_compaction_paused_.load(std::memory_order_acquire) > 0) { return Status::Incomplete(Status::SubCode::kManualCompactionPaused); } std::unordered_set input_set; for (const auto& file_name : input_file_names) { input_set.insert(TableFileNameToNumber(file_name)); } ColumnFamilyMetaData cf_meta; // TODO(yhchiang): can directly use version here if none of the // following functions call is pluggable to external developers. version->GetColumnFamilyMetaData(&cf_meta); if (output_path_id < 0) { if (cfd->ioptions()->cf_paths.size() == 1U) { output_path_id = 0; } else { return Status::NotSupported( "Automatic output path selection is not " "yet supported in CompactFiles()"); } } Status s = cfd->compaction_picker()->SanitizeCompactionInputFiles( &input_set, cf_meta, output_level); TEST_SYNC_POINT("DBImpl::CompactFilesImpl::PostSanitizeCompactionInputFiles"); if (!s.ok()) { return s; } std::vector input_files; s = cfd->compaction_picker()->GetCompactionInputsFromFileNumbers( &input_files, &input_set, version->storage_info(), compact_options); if (!s.ok()) { return s; } for (const auto& inputs : input_files) { if (cfd->compaction_picker()->AreFilesInCompaction(inputs.files)) { return Status::Aborted( "Some of the necessary compaction input " "files are already being compacted"); } } bool sfm_reserved_compact_space = false; // First check if we have enough room to do the compaction bool enough_room = EnoughRoomForCompaction( cfd, input_files, &sfm_reserved_compact_space, log_buffer); if (!enough_room) { // m's vars will get set properly at the end of this function, // as long as status == CompactionTooLarge return Status::CompactionTooLarge(); } // At this point, CompactFiles will be run. bg_compaction_scheduled_++; std::unique_ptr c; assert(cfd->compaction_picker()); c.reset(cfd->compaction_picker()->CompactFiles( compact_options, input_files, output_level, version->storage_info(), *cfd->GetLatestMutableCFOptions(), mutable_db_options_, output_path_id)); // we already sanitized the set of input files and checked for conflicts // without releasing the lock, so we're guaranteed a compaction can be formed. assert(c != nullptr); c->SetInputVersion(version); // deletion compaction currently not allowed in CompactFiles. assert(!c->deletion_compaction()); std::vector snapshot_seqs; SequenceNumber earliest_write_conflict_snapshot; SnapshotChecker* snapshot_checker; GetSnapshotContext(job_context, &snapshot_seqs, &earliest_write_conflict_snapshot, &snapshot_checker); std::unique_ptr::iterator> pending_outputs_inserted_elem( new std::list::iterator( CaptureCurrentFileNumberInPendingOutputs())); assert(is_snapshot_supported_ || snapshots_.empty()); CompactionJobStats compaction_job_stats; CompactionJob compaction_job( job_context->job_id, c.get(), immutable_db_options_, mutable_db_options_, file_options_for_compaction_, versions_.get(), &shutting_down_, log_buffer, directories_.GetDbDir(), GetDataDir(c->column_family_data(), c->output_path_id()), GetDataDir(c->column_family_data(), 0), stats_, &mutex_, &error_handler_, snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker, job_context, table_cache_, &event_logger_, c->mutable_cf_options()->paranoid_file_checks, c->mutable_cf_options()->report_bg_io_stats, dbname_, &compaction_job_stats, Env::Priority::USER, io_tracer_, kManualCompactionCanceledFalse_, db_id_, db_session_id_, c->column_family_data()->GetFullHistoryTsLow(), c->trim_ts(), &blob_callback_, &bg_compaction_scheduled_, &bg_bottom_compaction_scheduled_); // Creating a compaction influences the compaction score because the score // takes running compactions into account (by skipping files that are already // being compacted). Since we just changed compaction score, we recalculate it // here. version->storage_info()->ComputeCompactionScore(*cfd->ioptions(), *c->mutable_cf_options()); compaction_job.Prepare(); mutex_.Unlock(); TEST_SYNC_POINT("CompactFilesImpl:0"); TEST_SYNC_POINT("CompactFilesImpl:1"); // Ignore the status here, as it will be checked in the Install down below... compaction_job.Run().PermitUncheckedError(); TEST_SYNC_POINT("CompactFilesImpl:2"); TEST_SYNC_POINT("CompactFilesImpl:3"); mutex_.Lock(); Status status = compaction_job.Install(*c->mutable_cf_options()); if (status.ok()) { assert(compaction_job.io_status().ok()); InstallSuperVersionAndScheduleWork(c->column_family_data(), &job_context->superversion_contexts[0], *c->mutable_cf_options()); } // status above captures any error during compaction_job.Install, so its ok // not check compaction_job.io_status() explicitly if we're not calling // SetBGError compaction_job.io_status().PermitUncheckedError(); c->ReleaseCompactionFiles(s); // Need to make sure SstFileManager does its bookkeeping auto sfm = static_cast( immutable_db_options_.sst_file_manager.get()); if (sfm && sfm_reserved_compact_space) { sfm->OnCompactionCompletion(c.get()); } ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem); if (compaction_job_info != nullptr) { BuildCompactionJobInfo(cfd, c.get(), s, compaction_job_stats, job_context->job_id, version, compaction_job_info); } if (status.ok()) { // Done } else if (status.IsColumnFamilyDropped() || status.IsShutdownInProgress()) { // Ignore compaction errors found during shutting down } else if (status.IsManualCompactionPaused()) { // Don't report stopping manual compaction as error ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] [JOB %d] Stopping manual compaction", c->column_family_data()->GetName().c_str(), job_context->job_id); } else { ROCKS_LOG_WARN(immutable_db_options_.info_log, "[%s] [JOB %d] Compaction error: %s", c->column_family_data()->GetName().c_str(), job_context->job_id, status.ToString().c_str()); IOStatus io_s = compaction_job.io_status(); if (!io_s.ok()) { error_handler_.SetBGError(io_s, BackgroundErrorReason::kCompaction); } else { error_handler_.SetBGError(status, BackgroundErrorReason::kCompaction); } } if (output_file_names != nullptr) { for (const auto& newf : c->edit()->GetNewFiles()) { output_file_names->push_back(TableFileName( c->immutable_options()->cf_paths, newf.second.fd.GetNumber(), newf.second.fd.GetPathId())); } for (const auto& blob_file : c->edit()->GetBlobFileAdditions()) { output_file_names->push_back( BlobFileName(c->immutable_options()->cf_paths.front().path, blob_file.GetBlobFileNumber())); } } c.reset(); bg_compaction_scheduled_--; if (bg_compaction_scheduled_ == 0) { bg_cv_.SignalAll(); } MaybeScheduleFlushOrCompaction(); TEST_SYNC_POINT("CompactFilesImpl:End"); return status; } Status DBImpl::PauseBackgroundWork() { InstrumentedMutexLock guard_lock(&mutex_); bg_compaction_paused_++; while (bg_bottom_compaction_scheduled_ > 0 || bg_compaction_scheduled_ > 0 || bg_flush_scheduled_ > 0) { bg_cv_.Wait(); } bg_work_paused_++; return Status::OK(); } Status DBImpl::ContinueBackgroundWork() { InstrumentedMutexLock guard_lock(&mutex_); if (bg_work_paused_ == 0) { return Status::InvalidArgument(); } assert(bg_work_paused_ > 0); assert(bg_compaction_paused_ > 0); bg_compaction_paused_--; bg_work_paused_--; // It's sufficient to check just bg_work_paused_ here since // bg_work_paused_ is always no greater than bg_compaction_paused_ if (bg_work_paused_ == 0) { MaybeScheduleFlushOrCompaction(); } return Status::OK(); } void DBImpl::NotifyOnCompactionBegin(ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& job_stats, int job_id) { if (immutable_db_options_.listeners.empty()) { return; } mutex_.AssertHeld(); if (shutting_down_.load(std::memory_order_acquire)) { return; } if (c->is_manual_compaction() && manual_compaction_paused_.load(std::memory_order_acquire) > 0) { return; } c->SetNotifyOnCompactionCompleted(); Version* current = cfd->current(); current->Ref(); // release lock while notifying events mutex_.Unlock(); TEST_SYNC_POINT("DBImpl::NotifyOnCompactionBegin::UnlockMutex"); { CompactionJobInfo info{}; BuildCompactionJobInfo(cfd, c, st, job_stats, job_id, current, &info); for (auto listener : immutable_db_options_.listeners) { listener->OnCompactionBegin(this, info); } info.status.PermitUncheckedError(); } mutex_.Lock(); current->Unref(); } void DBImpl::NotifyOnCompactionCompleted( ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& compaction_job_stats, const int job_id) { if (immutable_db_options_.listeners.size() == 0U) { return; } mutex_.AssertHeld(); if (shutting_down_.load(std::memory_order_acquire)) { return; } if (c->ShouldNotifyOnCompactionCompleted() == false) { return; } Version* current = cfd->current(); current->Ref(); // release lock while notifying events mutex_.Unlock(); TEST_SYNC_POINT("DBImpl::NotifyOnCompactionCompleted::UnlockMutex"); { CompactionJobInfo info{}; BuildCompactionJobInfo(cfd, c, st, compaction_job_stats, job_id, current, &info); for (auto listener : immutable_db_options_.listeners) { listener->OnCompactionCompleted(this, info); } } mutex_.Lock(); current->Unref(); // no need to signal bg_cv_ as it will be signaled at the end of the // flush process. } // REQUIREMENT: block all background work by calling PauseBackgroundWork() // before calling this function Status DBImpl::ReFitLevel(ColumnFamilyData* cfd, int level, int target_level) { assert(level < cfd->NumberLevels()); if (target_level >= cfd->NumberLevels()) { return Status::InvalidArgument("Target level exceeds number of levels"); } SuperVersionContext sv_context(/* create_superversion */ true); InstrumentedMutexLock guard_lock(&mutex_); auto* vstorage = cfd->current()->storage_info(); if (vstorage->LevelFiles(level).empty()) { return Status::OK(); } // only allow one thread refitting if (refitting_level_) { ROCKS_LOG_INFO(immutable_db_options_.info_log, "[ReFitLevel] another thread is refitting"); return Status::NotSupported("another thread is refitting"); } refitting_level_ = true; const MutableCFOptions mutable_cf_options = *cfd->GetLatestMutableCFOptions(); // move to a smaller level int to_level = target_level; if (target_level < 0) { to_level = FindMinimumEmptyLevelFitting(cfd, mutable_cf_options, level); } if (to_level != level) { std::vector input(1); input[0].level = level; for (auto& f : vstorage->LevelFiles(level)) { input[0].files.push_back(f); } InternalKey refit_level_smallest; InternalKey refit_level_largest; cfd->compaction_picker()->GetRange(input[0], &refit_level_smallest, &refit_level_largest); if (to_level > level) { if (level == 0) { refitting_level_ = false; return Status::NotSupported( "Cannot change from level 0 to other levels."); } // Check levels are empty for a trivial move for (int l = level + 1; l <= to_level; l++) { if (vstorage->NumLevelFiles(l) > 0) { refitting_level_ = false; return Status::NotSupported( "Levels between source and target are not empty for a move."); } if (cfd->RangeOverlapWithCompaction(refit_level_smallest.user_key(), refit_level_largest.user_key(), l)) { refitting_level_ = false; return Status::NotSupported( "Levels between source and target " "will have some ongoing compaction's output."); } } } else { // to_level < level // Check levels are empty for a trivial move for (int l = to_level; l < level; l++) { if (vstorage->NumLevelFiles(l) > 0) { refitting_level_ = false; return Status::NotSupported( "Levels between source and target are not empty for a move."); } if (cfd->RangeOverlapWithCompaction(refit_level_smallest.user_key(), refit_level_largest.user_key(), l)) { refitting_level_ = false; return Status::NotSupported( "Levels between source and target " "will have some ongoing compaction's output."); } } } ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "[%s] Before refitting:\n%s", cfd->GetName().c_str(), cfd->current()->DebugString().data()); std::unique_ptr c(new Compaction( vstorage, *cfd->ioptions(), mutable_cf_options, mutable_db_options_, {input}, to_level, MaxFileSizeForLevel( mutable_cf_options, to_level, cfd->ioptions() ->compaction_style) /* output file size limit, not applicable */ , LLONG_MAX /* max compaction bytes, not applicable */, 0 /* output path ID, not applicable */, mutable_cf_options.compression, mutable_cf_options.compression_opts, Temperature::kUnknown, 0 /* max_subcompactions, not applicable */, {} /* grandparents, not applicable */, false /* is manual */, "" /* trim_ts */, -1 /* score, not applicable */, false /* is deletion compaction, not applicable */, false /* l0_files_might_overlap, not applicable */, CompactionReason::kRefitLevel)); cfd->compaction_picker()->RegisterCompaction(c.get()); TEST_SYNC_POINT("DBImpl::ReFitLevel:PostRegisterCompaction"); VersionEdit edit; edit.SetColumnFamily(cfd->GetID()); for (const auto& f : vstorage->LevelFiles(level)) { edit.DeleteFile(level, f->fd.GetNumber()); edit.AddFile( to_level, f->fd.GetNumber(), f->fd.GetPathId(), f->fd.GetFileSize(), f->smallest, f->largest, f->fd.smallest_seqno, f->fd.largest_seqno, f->marked_for_compaction, f->temperature, f->oldest_blob_file_number, f->oldest_ancester_time, f->file_creation_time, f->epoch_number, f->file_checksum, f->file_checksum_func_name, f->unique_id, f->compensated_range_deletion_size); } ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "[%s] Apply version edit:\n%s", cfd->GetName().c_str(), edit.DebugString().data()); Status status = versions_->LogAndApply(cfd, mutable_cf_options, &edit, &mutex_, directories_.GetDbDir()); cfd->compaction_picker()->UnregisterCompaction(c.get()); c.reset(); InstallSuperVersionAndScheduleWork(cfd, &sv_context, mutable_cf_options); ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "[%s] LogAndApply: %s\n", cfd->GetName().c_str(), status.ToString().data()); if (status.ok()) { ROCKS_LOG_DEBUG(immutable_db_options_.info_log, "[%s] After refitting:\n%s", cfd->GetName().c_str(), cfd->current()->DebugString().data()); } sv_context.Clean(); refitting_level_ = false; return status; } refitting_level_ = false; return Status::OK(); } int DBImpl::NumberLevels(ColumnFamilyHandle* column_family) { auto cfh = static_cast_with_check(column_family); return cfh->cfd()->NumberLevels(); } int DBImpl::MaxMemCompactionLevel(ColumnFamilyHandle* /*column_family*/) { return 0; } int DBImpl::Level0StopWriteTrigger(ColumnFamilyHandle* column_family) { auto cfh = static_cast_with_check(column_family); InstrumentedMutexLock l(&mutex_); return cfh->cfd() ->GetSuperVersion() ->mutable_cf_options.level0_stop_writes_trigger; } Status DBImpl::Flush(const FlushOptions& flush_options, ColumnFamilyHandle* column_family) { auto cfh = static_cast_with_check(column_family); ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] Manual flush start.", cfh->GetName().c_str()); Status s; if (immutable_db_options_.atomic_flush) { s = AtomicFlushMemTables(flush_options, FlushReason::kManualFlush, {cfh->cfd()}); } else { s = FlushMemTable(cfh->cfd(), flush_options, FlushReason::kManualFlush); } ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] Manual flush finished, status: %s\n", cfh->GetName().c_str(), s.ToString().c_str()); return s; } Status DBImpl::Flush(const FlushOptions& flush_options, const std::vector& column_families) { Status s; if (!immutable_db_options_.atomic_flush) { for (auto cfh : column_families) { s = Flush(flush_options, cfh); if (!s.ok()) { break; } } } else { ROCKS_LOG_INFO(immutable_db_options_.info_log, "Manual atomic flush start.\n" "=====Column families:====="); for (auto cfh : column_families) { auto cfhi = static_cast(cfh); ROCKS_LOG_INFO(immutable_db_options_.info_log, "%s", cfhi->GetName().c_str()); } ROCKS_LOG_INFO(immutable_db_options_.info_log, "=====End of column families list====="); autovector cfds; std::for_each(column_families.begin(), column_families.end(), [&cfds](ColumnFamilyHandle* elem) { auto cfh = static_cast(elem); cfds.emplace_back(cfh->cfd()); }); s = AtomicFlushMemTables(flush_options, FlushReason::kManualFlush, cfds); ROCKS_LOG_INFO(immutable_db_options_.info_log, "Manual atomic flush finished, status: %s\n" "=====Column families:=====", s.ToString().c_str()); for (auto cfh : column_families) { auto cfhi = static_cast(cfh); ROCKS_LOG_INFO(immutable_db_options_.info_log, "%s", cfhi->GetName().c_str()); } ROCKS_LOG_INFO(immutable_db_options_.info_log, "=====End of column families list====="); } return s; } Status DBImpl::RunManualCompaction( ColumnFamilyData* cfd, int input_level, int output_level, const CompactRangeOptions& compact_range_options, const Slice* begin, const Slice* end, bool exclusive, bool disallow_trivial_move, uint64_t max_file_num_to_ignore, const std::string& trim_ts) { assert(input_level == ColumnFamilyData::kCompactAllLevels || input_level >= 0); InternalKey begin_storage, end_storage; CompactionArg* ca = nullptr; bool scheduled = false; bool unscheduled = false; Env::Priority thread_pool_priority = Env::Priority::TOTAL; bool manual_conflict = false; ManualCompactionState manual( cfd, input_level, output_level, compact_range_options.target_path_id, exclusive, disallow_trivial_move, compact_range_options.canceled); // For universal compaction, we enforce every manual compaction to compact // all files. if (begin == nullptr || cfd->ioptions()->compaction_style == kCompactionStyleUniversal || cfd->ioptions()->compaction_style == kCompactionStyleFIFO) { manual.begin = nullptr; } else { begin_storage.SetMinPossibleForUserKey(*begin); manual.begin = &begin_storage; } if (end == nullptr || cfd->ioptions()->compaction_style == kCompactionStyleUniversal || cfd->ioptions()->compaction_style == kCompactionStyleFIFO) { manual.end = nullptr; } else { end_storage.SetMaxPossibleForUserKey(*end); manual.end = &end_storage; } TEST_SYNC_POINT("DBImpl::RunManualCompaction:0"); TEST_SYNC_POINT("DBImpl::RunManualCompaction:1"); InstrumentedMutexLock l(&mutex_); if (manual_compaction_paused_ > 0) { // Does not make sense to `AddManualCompaction()` in this scenario since // `DisableManualCompaction()` just waited for the manual compaction queue // to drain. So return immediately. TEST_SYNC_POINT("DBImpl::RunManualCompaction:PausedAtStart"); manual.status = Status::Incomplete(Status::SubCode::kManualCompactionPaused); manual.done = true; return manual.status; } // When a manual compaction arrives, temporarily disable scheduling of // non-manual compactions and wait until the number of scheduled compaction // jobs drops to zero. This used to be needed to ensure that this manual // compaction can compact any range of keys/files. Now it is optional // (see `CompactRangeOptions::exclusive_manual_compaction`). The use case for // `exclusive_manual_compaction=true` is unclear beyond not trusting the code. // // HasPendingManualCompaction() is true when at least one thread is inside // RunManualCompaction(), i.e. during that time no other compaction will // get scheduled (see MaybeScheduleFlushOrCompaction). // // Note that the following loop doesn't stop more that one thread calling // RunManualCompaction() from getting to the second while loop below. // However, only one of them will actually schedule compaction, while // others will wait on a condition variable until it completes. AddManualCompaction(&manual); TEST_SYNC_POINT_CALLBACK("DBImpl::RunManualCompaction:NotScheduled", &mutex_); if (exclusive) { // Limitation: there's no way to wake up the below loop when user sets // `*manual.canceled`. So `CompactRangeOptions::exclusive_manual_compaction` // and `CompactRangeOptions::canceled` might not work well together. while (bg_bottom_compaction_scheduled_ > 0 || bg_compaction_scheduled_ > 0) { if (manual_compaction_paused_ > 0 || manual.canceled == true) { // Pretend the error came from compaction so the below cleanup/error // handling code can process it. manual.done = true; manual.status = Status::Incomplete(Status::SubCode::kManualCompactionPaused); break; } TEST_SYNC_POINT("DBImpl::RunManualCompaction:WaitScheduled"); ROCKS_LOG_INFO( immutable_db_options_.info_log, "[%s] Manual compaction waiting for all other scheduled background " "compactions to finish", cfd->GetName().c_str()); bg_cv_.Wait(); } } LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, immutable_db_options_.info_log.get()); ROCKS_LOG_BUFFER(&log_buffer, "[%s] Manual compaction starting", cfd->GetName().c_str()); // We don't check bg_error_ here, because if we get the error in compaction, // the compaction will set manual.status to bg_error_ and set manual.done to // true. while (!manual.done) { assert(HasPendingManualCompaction()); manual_conflict = false; Compaction* compaction = nullptr; if (ShouldntRunManualCompaction(&manual) || (manual.in_progress == true) || scheduled || (((manual.manual_end = &manual.tmp_storage1) != nullptr) && ((compaction = manual.cfd->CompactRange( *manual.cfd->GetLatestMutableCFOptions(), mutable_db_options_, manual.input_level, manual.output_level, compact_range_options, manual.begin, manual.end, &manual.manual_end, &manual_conflict, max_file_num_to_ignore, trim_ts)) == nullptr && manual_conflict))) { if (!scheduled) { // There is a conflicting compaction if (manual_compaction_paused_ > 0 || manual.canceled == true) { // Stop waiting since it was canceled. Pretend the error came from // compaction so the below cleanup/error handling code can process it. manual.done = true; manual.status = Status::Incomplete(Status::SubCode::kManualCompactionPaused); } } if (!manual.done) { bg_cv_.Wait(); } if (manual_compaction_paused_ > 0 && scheduled && !unscheduled) { assert(thread_pool_priority != Env::Priority::TOTAL); // unschedule all manual compactions auto unscheduled_task_num = env_->UnSchedule( GetTaskTag(TaskType::kManualCompaction), thread_pool_priority); if (unscheduled_task_num > 0) { ROCKS_LOG_INFO( immutable_db_options_.info_log, "[%s] Unscheduled %d number of manual compactions from the " "thread-pool", cfd->GetName().c_str(), unscheduled_task_num); // it may unschedule other manual compactions, notify others. bg_cv_.SignalAll(); } unscheduled = true; TEST_SYNC_POINT("DBImpl::RunManualCompaction:Unscheduled"); } if (scheduled && manual.incomplete == true) { assert(!manual.in_progress); scheduled = false; manual.incomplete = false; } } else if (!scheduled) { if (compaction == nullptr) { manual.done = true; bg_cv_.SignalAll(); continue; } ca = new CompactionArg; ca->db = this; ca->prepicked_compaction = new PrepickedCompaction; ca->prepicked_compaction->manual_compaction_state = &manual; ca->prepicked_compaction->compaction = compaction; if (!RequestCompactionToken( cfd, true, &ca->prepicked_compaction->task_token, &log_buffer)) { // Don't throttle manual compaction, only count outstanding tasks. assert(false); } manual.incomplete = false; if (compaction->bottommost_level() && env_->GetBackgroundThreads(Env::Priority::BOTTOM) > 0) { bg_bottom_compaction_scheduled_++; ca->compaction_pri_ = Env::Priority::BOTTOM; env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca, Env::Priority::BOTTOM, GetTaskTag(TaskType::kManualCompaction), &DBImpl::UnscheduleCompactionCallback); thread_pool_priority = Env::Priority::BOTTOM; } else { bg_compaction_scheduled_++; ca->compaction_pri_ = Env::Priority::LOW; env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, GetTaskTag(TaskType::kManualCompaction), &DBImpl::UnscheduleCompactionCallback); thread_pool_priority = Env::Priority::LOW; } scheduled = true; TEST_SYNC_POINT("DBImpl::RunManualCompaction:Scheduled"); } } log_buffer.FlushBufferToLog(); assert(!manual.in_progress); assert(HasPendingManualCompaction()); RemoveManualCompaction(&manual); // if the manual job is unscheduled, try schedule other jobs in case there's // any unscheduled compaction job which was blocked by exclusive manual // compaction. if (manual.status.IsIncomplete() && manual.status.subcode() == Status::SubCode::kManualCompactionPaused) { MaybeScheduleFlushOrCompaction(); } bg_cv_.SignalAll(); return manual.status; } void DBImpl::GenerateFlushRequest(const autovector& cfds, FlushReason flush_reason, FlushRequest* req) { assert(req != nullptr); req->flush_reason = flush_reason; req->cfd_to_max_mem_id_to_persist.reserve(cfds.size()); for (const auto cfd : cfds) { if (nullptr == cfd) { // cfd may be null, see DBImpl::ScheduleFlushes continue; } uint64_t max_memtable_id = cfd->imm()->GetLatestMemTableID(); req->cfd_to_max_mem_id_to_persist.emplace(cfd, max_memtable_id); } } Status DBImpl::FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& flush_options, FlushReason flush_reason, bool entered_write_thread) { // This method should not be called if atomic_flush is true. assert(!immutable_db_options_.atomic_flush); if (!flush_options.wait && write_controller_->IsStopped()) { std::ostringstream oss; oss << "Writes have been stopped, thus unable to perform manual flush. " "Please try again later after writes are resumed"; return Status::TryAgain(oss.str()); } Status s; if (!flush_options.allow_write_stall) { bool flush_needed = true; s = WaitUntilFlushWouldNotStallWrites(cfd, &flush_needed); TEST_SYNC_POINT("DBImpl::FlushMemTable:StallWaitDone"); if (!s.ok() || !flush_needed) { return s; } } const bool needs_to_join_write_thread = !entered_write_thread; autovector flush_reqs; autovector memtable_ids_to_wait; { SuspendSpdbWrites(); WriteContext context; InstrumentedMutexLock guard_lock(&mutex_); WriteThread::Writer w; WriteThread::Writer nonmem_w; if (needs_to_join_write_thread) { write_thread_.EnterUnbatched(&w, &mutex_); if (two_write_queues_) { nonmem_write_thread_.EnterUnbatched(&nonmem_w, &mutex_); } } WaitForPendingWrites(); if (flush_reason != FlushReason::kErrorRecoveryRetryFlush && (!cfd->mem()->IsEmpty() || !cached_recoverable_state_empty_.load())) { // Note that, when flush reason is kErrorRecoveryRetryFlush, during the // auto retry resume, we want to avoid creating new small memtables. // Therefore, SwitchMemtable will not be called. Also, since ResumeImpl // will iterate through all the CFs and call FlushMemtable during auto // retry resume, it is possible that in some CFs, // cfd->imm()->NumNotFlushed() = 0. In this case, so no flush request will // be created and scheduled, status::OK() will be returned. s = SwitchMemtable(cfd, &context); } const uint64_t flush_memtable_id = std::numeric_limits::max(); if (s.ok()) { if (cfd->imm()->NumNotFlushed() != 0 || !cfd->mem()->IsEmpty() || !cached_recoverable_state_empty_.load()) { FlushRequest req{flush_reason, {{cfd, flush_memtable_id}}}; flush_reqs.emplace_back(std::move(req)); memtable_ids_to_wait.emplace_back(cfd->imm()->GetLatestMemTableID()); } if (immutable_db_options_.persist_stats_to_disk && flush_reason != FlushReason::kErrorRecoveryRetryFlush) { ColumnFamilyData* cfd_stats = versions_->GetColumnFamilySet()->GetColumnFamily( kPersistentStatsColumnFamilyName); if (cfd_stats != nullptr && cfd_stats != cfd && !cfd_stats->mem()->IsEmpty()) { // only force flush stats CF when it will be the only CF lagging // behind after the current flush bool stats_cf_flush_needed = true; for (auto* loop_cfd : *versions_->GetColumnFamilySet()) { if (loop_cfd == cfd_stats || loop_cfd == cfd) { continue; } if (loop_cfd->GetLogNumber() <= cfd_stats->GetLogNumber()) { stats_cf_flush_needed = false; } } if (stats_cf_flush_needed) { ROCKS_LOG_INFO(immutable_db_options_.info_log, "Force flushing stats CF with manual flush of %s " "to avoid holding old logs", cfd->GetName().c_str()); s = SwitchMemtable(cfd_stats, &context); FlushRequest req{flush_reason, {{cfd_stats, flush_memtable_id}}}; flush_reqs.emplace_back(std::move(req)); memtable_ids_to_wait.emplace_back( cfd_stats->imm()->GetLatestMemTableID()); } } } } ResumeSpdbWrites(); if (s.ok() && !flush_reqs.empty()) { for (const auto& req : flush_reqs) { assert(req.cfd_to_max_mem_id_to_persist.size() == 1); ColumnFamilyData* loop_cfd = req.cfd_to_max_mem_id_to_persist.begin()->first; loop_cfd->imm()->FlushRequested(); } // If the caller wants to wait for this flush to complete, it indicates // that the caller expects the ColumnFamilyData not to be free'ed by // other threads which may drop the column family concurrently. // Therefore, we increase the cfd's ref count. if (flush_options.wait) { for (const auto& req : flush_reqs) { assert(req.cfd_to_max_mem_id_to_persist.size() == 1); ColumnFamilyData* loop_cfd = req.cfd_to_max_mem_id_to_persist.begin()->first; loop_cfd->Ref(); } } for (const auto& req : flush_reqs) { SchedulePendingFlush(req); } MaybeScheduleFlushOrCompaction(); } if (needs_to_join_write_thread) { write_thread_.ExitUnbatched(&w); if (two_write_queues_) { nonmem_write_thread_.ExitUnbatched(&nonmem_w); } } } TEST_SYNC_POINT("DBImpl::FlushMemTable:AfterScheduleFlush"); TEST_SYNC_POINT("DBImpl::FlushMemTable:BeforeWaitForBgFlush"); if (s.ok() && flush_options.wait) { autovector cfds; autovector flush_memtable_ids; assert(flush_reqs.size() == memtable_ids_to_wait.size()); for (size_t i = 0; i < flush_reqs.size(); ++i) { assert(flush_reqs[i].cfd_to_max_mem_id_to_persist.size() == 1); cfds.push_back(flush_reqs[i].cfd_to_max_mem_id_to_persist.begin()->first); flush_memtable_ids.push_back(&(memtable_ids_to_wait[i])); } s = WaitForFlushMemTables( cfds, flush_memtable_ids, (flush_reason == FlushReason::kErrorRecovery || flush_reason == FlushReason::kErrorRecoveryRetryFlush)); InstrumentedMutexLock lock_guard(&mutex_); for (auto* tmp_cfd : cfds) { tmp_cfd->UnrefAndTryDelete(); } } TEST_SYNC_POINT("DBImpl::FlushMemTable:FlushMemTableFinished"); return s; } Status DBImpl::AtomicFlushMemTables( const FlushOptions& flush_options, FlushReason flush_reason, const autovector& provided_candidate_cfds, bool entered_write_thread) { assert(immutable_db_options_.atomic_flush); if (!flush_options.wait && write_controller_->IsStopped()) { std::ostringstream oss; oss << "Writes have been stopped, thus unable to perform manual flush. " "Please try again later after writes are resumed"; return Status::TryAgain(oss.str()); } Status s; autovector candidate_cfds; if (provided_candidate_cfds.empty()) { // Generate candidate cfds if not provided { InstrumentedMutexLock l(&mutex_); for (ColumnFamilyData* cfd : *versions_->GetColumnFamilySet()) { if (!cfd->IsDropped() && cfd->initialized()) { cfd->Ref(); candidate_cfds.push_back(cfd); } } } } else { candidate_cfds = provided_candidate_cfds; } if (!flush_options.allow_write_stall) { int num_cfs_to_flush = 0; for (auto cfd : candidate_cfds) { bool flush_needed = true; s = WaitUntilFlushWouldNotStallWrites(cfd, &flush_needed); if (!s.ok()) { // Unref the newly generated candidate cfds (when not provided) in // `candidate_cfds` if (provided_candidate_cfds.empty()) { for (auto candidate_cfd : candidate_cfds) { candidate_cfd->UnrefAndTryDelete(); } } return s; } else if (flush_needed) { ++num_cfs_to_flush; } } if (0 == num_cfs_to_flush) { // Unref the newly generated candidate cfds (when not provided) in // `candidate_cfds` if (provided_candidate_cfds.empty()) { for (auto candidate_cfd : candidate_cfds) { candidate_cfd->UnrefAndTryDelete(); } } return s; } } const bool needs_to_join_write_thread = !entered_write_thread; FlushRequest flush_req; autovector cfds; { SuspendSpdbWrites(); WriteContext context; InstrumentedMutexLock guard_lock(&mutex_); WriteThread::Writer w; WriteThread::Writer nonmem_w; if (needs_to_join_write_thread) { write_thread_.EnterUnbatched(&w, &mutex_); if (two_write_queues_) { nonmem_write_thread_.EnterUnbatched(&nonmem_w, &mutex_); } } WaitForPendingWrites(); SelectColumnFamiliesForAtomicFlush(&cfds, candidate_cfds); // Unref the newly generated candidate cfds (when not provided) in // `candidate_cfds` if (provided_candidate_cfds.empty()) { for (auto candidate_cfd : candidate_cfds) { candidate_cfd->UnrefAndTryDelete(); } } for (auto cfd : cfds) { if ((cfd->mem()->IsEmpty() && cached_recoverable_state_empty_.load()) || flush_reason == FlushReason::kErrorRecoveryRetryFlush) { continue; } cfd->Ref(); s = SwitchMemtable(cfd, &context); cfd->UnrefAndTryDelete(); if (!s.ok()) { break; } } ResumeSpdbWrites(); if (s.ok()) { AssignAtomicFlushSeq(cfds); for (auto cfd : cfds) { cfd->imm()->FlushRequested(); } // If the caller wants to wait for this flush to complete, it indicates // that the caller expects the ColumnFamilyData not to be free'ed by // other threads which may drop the column family concurrently. // Therefore, we increase the cfd's ref count. if (flush_options.wait) { for (auto cfd : cfds) { cfd->Ref(); } } GenerateFlushRequest(cfds, flush_reason, &flush_req); SchedulePendingFlush(flush_req); MaybeScheduleFlushOrCompaction(); } if (needs_to_join_write_thread) { write_thread_.ExitUnbatched(&w); if (two_write_queues_) { nonmem_write_thread_.ExitUnbatched(&nonmem_w); } } } TEST_SYNC_POINT("DBImpl::AtomicFlushMemTables:AfterScheduleFlush"); TEST_SYNC_POINT("DBImpl::AtomicFlushMemTables:BeforeWaitForBgFlush"); if (s.ok() && flush_options.wait) { autovector flush_memtable_ids; for (auto& iter : flush_req.cfd_to_max_mem_id_to_persist) { flush_memtable_ids.push_back(&(iter.second)); } s = WaitForFlushMemTables( cfds, flush_memtable_ids, (flush_reason == FlushReason::kErrorRecovery || flush_reason == FlushReason::kErrorRecoveryRetryFlush)); InstrumentedMutexLock lock_guard(&mutex_); for (auto* cfd : cfds) { cfd->UnrefAndTryDelete(); } } return s; } // Calling FlushMemTable(), whether from DB::Flush() or from Backup Engine, can // cause write stall, for example if one memtable is being flushed already. // This method tries to avoid write stall (similar to CompactRange() behavior) // it emulates how the SuperVersion / LSM would change if flush happens, checks // it against various constrains and delays flush if it'd cause write stall. // Caller should check status and flush_needed to see if flush already happened. Status DBImpl::WaitUntilFlushWouldNotStallWrites(ColumnFamilyData* cfd, bool* flush_needed) { { *flush_needed = true; InstrumentedMutexLock l(&mutex_); uint64_t orig_active_memtable_id = cfd->mem()->GetID(); WriteStallCondition write_stall_condition = WriteStallCondition::kNormal; do { if (write_stall_condition != WriteStallCondition::kNormal) { // Same error handling as user writes: Don't wait if there's a // background error, even if it's a soft error. We might wait here // indefinitely as the pending flushes/compactions may never finish // successfully, resulting in the stall condition lasting indefinitely if (error_handler_.IsBGWorkStopped()) { return error_handler_.GetBGError(); } TEST_SYNC_POINT("DBImpl::WaitUntilFlushWouldNotStallWrites:StallWait"); ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] WaitUntilFlushWouldNotStallWrites" " waiting on stall conditions to clear", cfd->GetName().c_str()); bg_cv_.Wait(); } if (cfd->IsDropped()) { return Status::ColumnFamilyDropped(); } if (shutting_down_.load(std::memory_order_acquire)) { return Status::ShutdownInProgress(); } uint64_t earliest_memtable_id = std::min(cfd->mem()->GetID(), cfd->imm()->GetEarliestMemTableID()); if (earliest_memtable_id > orig_active_memtable_id) { // We waited so long that the memtable we were originally waiting on was // flushed. *flush_needed = false; return Status::OK(); } const auto& mutable_cf_options = *cfd->GetLatestMutableCFOptions(); const auto* vstorage = cfd->current()->storage_info(); // Skip stalling check if we're below auto-flush and auto-compaction // triggers. If it stalled in these conditions, that'd mean the stall // triggers are so low that stalling is needed for any background work. In // that case we shouldn't wait since background work won't be scheduled. if (cfd->imm()->NumNotFlushed() < cfd->ioptions()->min_write_buffer_number_to_merge && vstorage->l0_delay_trigger_count() < mutable_cf_options.level0_file_num_compaction_trigger) { break; } // check whether one extra immutable memtable or an extra L0 file would // cause write stalling mode to be entered. It could still enter stall // mode due to pending compaction bytes, but that's less common write_stall_condition = ColumnFamilyData::GetWriteStallConditionAndCause( cfd->imm()->NumNotFlushed() + 1, vstorage->l0_delay_trigger_count() + 1, vstorage->estimated_compaction_needed_bytes(), mutable_cf_options, *cfd->ioptions()) .first; } while (write_stall_condition != WriteStallCondition::kNormal); } return Status::OK(); } // Wait for memtables to be flushed for multiple column families. // let N = cfds.size() // for i in [0, N), // 1) if flush_memtable_ids[i] is not null, then the memtables with lower IDs // have to be flushed for THIS column family; // 2) if flush_memtable_ids[i] is null, then all memtables in THIS column // family have to be flushed. // Finish waiting when ALL column families finish flushing memtables. // resuming_from_bg_err indicates whether the caller is trying to resume from // background error or in normal processing. Status DBImpl::WaitForFlushMemTables( const autovector& cfds, const autovector& flush_memtable_ids, bool resuming_from_bg_err) { int num = static_cast(cfds.size()); // Wait until the compaction completes InstrumentedMutexLock l(&mutex_); Status s; // If the caller is trying to resume from bg error, then // error_handler_.IsDBStopped() is true. while (resuming_from_bg_err || !error_handler_.IsDBStopped()) { if (shutting_down_.load(std::memory_order_acquire)) { s = Status::ShutdownInProgress(); return s; } // If an error has occurred during resumption, then no need to wait. // But flush operation may fail because of this error, so need to // return the status. if (!error_handler_.GetRecoveryError().ok()) { s = error_handler_.GetRecoveryError(); break; } // If BGWorkStopped, which indicate that there is a BG error and // 1) soft error but requires no BG work, 2) no in auto_recovery_ if (!resuming_from_bg_err && error_handler_.IsBGWorkStopped() && error_handler_.GetBGError().severity() < Status::Severity::kHardError) { s = error_handler_.GetBGError(); return s; } // Number of column families that have been dropped. int num_dropped = 0; // Number of column families that have finished flush. int num_finished = 0; for (int i = 0; i < num; ++i) { if (cfds[i]->IsDropped()) { ++num_dropped; } else if (cfds[i]->imm()->NumNotFlushed() == 0 || (flush_memtable_ids[i] != nullptr && cfds[i]->imm()->GetEarliestMemTableID() > *flush_memtable_ids[i])) { ++num_finished; } } if (1 == num_dropped && 1 == num) { s = Status::ColumnFamilyDropped(); return s; } // Column families involved in this flush request have either been dropped // or finished flush. Then it's time to finish waiting. if (num_dropped + num_finished == num) { break; } bg_cv_.Wait(); } // If not resuming from bg error, and an error has caused the DB to stop, // then report the bg error to caller. if (!resuming_from_bg_err && error_handler_.IsDBStopped()) { s = error_handler_.GetBGError(); } return s; } Status DBImpl::EnableAutoCompaction( const std::vector& column_family_handles) { Status s; for (auto cf_ptr : column_family_handles) { Status status = this->SetOptions(cf_ptr, {{"disable_auto_compactions", "false"}}); if (!status.ok()) { s = status; } } return s; } // NOTE: Calling DisableManualCompaction() may overwrite the // user-provided canceled variable in CompactRangeOptions void DBImpl::DisableManualCompaction() { InstrumentedMutexLock l(&mutex_); manual_compaction_paused_.fetch_add(1, std::memory_order_release); // Mark the canceled as true when the cancellation is triggered by // manual_compaction_paused (may overwrite user-provided `canceled`) for (const auto& manual_compaction : manual_compaction_dequeue_) { manual_compaction->canceled = true; } // Wake up manual compactions waiting to start. bg_cv_.SignalAll(); // Wait for any pending manual compactions to finish (typically through // failing with `Status::Incomplete`) prior to returning. This way we are // guaranteed no pending manual compaction will commit while manual // compactions are "disabled". while (HasPendingManualCompaction()) { bg_cv_.Wait(); } } // NOTE: In contrast to DisableManualCompaction(), calling // EnableManualCompaction() does NOT overwrite the user-provided *canceled // variable to be false since there is NO CHANCE a canceled compaction // is uncanceled. In other words, a canceled compaction must have been // dropped out of the manual compaction queue, when we disable it. void DBImpl::EnableManualCompaction() { InstrumentedMutexLock l(&mutex_); assert(manual_compaction_paused_ > 0); manual_compaction_paused_.fetch_sub(1, std::memory_order_release); } void DBImpl::MaybeScheduleFlushOrCompaction() { mutex_.AssertHeld(); if (!opened_successfully_) { // Compaction may introduce data race to DB open return; } if (bg_work_paused_ > 0) { // we paused the background work return; } else if (error_handler_.IsBGWorkStopped() && !error_handler_.IsRecoveryInProgress()) { // There has been a hard error and this call is not part of the recovery // sequence. Bail out here so we don't get into an endless loop of // scheduling BG work which will again call this function return; } else if (shutting_down_.load(std::memory_order_acquire)) { // DB is being deleted; no more background compactions return; } auto bg_job_limits = GetBGJobLimits(); bool is_flush_pool_empty = env_->GetBackgroundThreads(Env::Priority::HIGH) == 0; while (!is_flush_pool_empty && unscheduled_flushes_ > 0 && bg_flush_scheduled_ < bg_job_limits.max_flushes) { bg_flush_scheduled_++; FlushThreadArg* fta = new FlushThreadArg; fta->db_ = this; fta->thread_pri_ = Env::Priority::HIGH; env_->Schedule(&DBImpl::BGWorkFlush, fta, Env::Priority::HIGH, this, &DBImpl::UnscheduleFlushCallback); --unscheduled_flushes_; TEST_SYNC_POINT_CALLBACK( "DBImpl::MaybeScheduleFlushOrCompaction:AfterSchedule:0", &unscheduled_flushes_); } // special case -- if high-pri (flush) thread pool is empty, then schedule // flushes in low-pri (compaction) thread pool. if (is_flush_pool_empty) { while (unscheduled_flushes_ > 0 && bg_flush_scheduled_ + bg_compaction_scheduled_ < bg_job_limits.max_flushes) { bg_flush_scheduled_++; FlushThreadArg* fta = new FlushThreadArg; fta->db_ = this; fta->thread_pri_ = Env::Priority::LOW; env_->Schedule(&DBImpl::BGWorkFlush, fta, Env::Priority::LOW, this, &DBImpl::UnscheduleFlushCallback); --unscheduled_flushes_; } } if (bg_compaction_paused_ > 0) { // we paused the background compaction return; } else if (error_handler_.IsBGWorkStopped()) { // Compaction is not part of the recovery sequence from a hard error. We // might get here because recovery might do a flush and install a new // super version, which will try to schedule pending compactions. Bail // out here and let the higher level recovery handle compactions return; } if (HasExclusiveManualCompaction()) { // only manual compactions are allowed to run. don't schedule automatic // compactions TEST_SYNC_POINT("DBImpl::MaybeScheduleFlushOrCompaction:Conflict"); return; } while (bg_compaction_scheduled_ + bg_bottom_compaction_scheduled_ < bg_job_limits.max_compactions && unscheduled_compactions_ > 0) { CompactionArg* ca = new CompactionArg; ca->db = this; ca->compaction_pri_ = Env::Priority::LOW; ca->prepicked_compaction = nullptr; bg_compaction_scheduled_++; unscheduled_compactions_--; env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this, &DBImpl::UnscheduleCompactionCallback); } } DBImpl::BGJobLimits DBImpl::GetBGJobLimits() const { mutex_.AssertHeld(); return GetBGJobLimits(mutable_db_options_.max_background_flushes, mutable_db_options_.max_background_compactions, mutable_db_options_.max_background_jobs, write_controller_->NeedSpeedupCompaction()); } DBImpl::BGJobLimits DBImpl::GetBGJobLimits(int max_background_flushes, int max_background_compactions, int max_background_jobs, bool parallelize_compactions) { BGJobLimits res; const int flushes = std::max(1, max_background_flushes); const int compactions = std::max(1, max_background_compactions); if ((max_background_flushes == -1 && max_background_compactions == -1) || (max_background_jobs > flushes + compactions)) { // for our first stab implementing max_background_jobs, simply allocate a // quarter of the threads to flushes. res.max_flushes = std::max(1, max_background_jobs / 4); res.max_compactions = std::max(1, max_background_jobs - res.max_flushes); } else { // compatibility code in case users haven't migrated to max_background_jobs, // which automatically computes flush/compaction limits res.max_flushes = std::max(1, max_background_flushes); res.max_compactions = std::max(1, max_background_compactions); } if (!parallelize_compactions) { // throttle background compactions until we deem necessary res.max_compactions = 1; } return res; } void DBImpl::AddToCompactionQueue(ColumnFamilyData* cfd) { assert(!cfd->queued_for_compaction()); cfd->Ref(); compaction_queue_.push_back(cfd); cfd->set_queued_for_compaction(true); } ColumnFamilyData* DBImpl::PopFirstFromCompactionQueue() { assert(!compaction_queue_.empty()); auto cfd = *compaction_queue_.begin(); compaction_queue_.pop_front(); assert(cfd->queued_for_compaction()); cfd->set_queued_for_compaction(false); return cfd; } DBImpl::FlushRequest DBImpl::PopFirstFromFlushQueue() { assert(!flush_queue_.empty()); FlushRequest flush_req = flush_queue_.front(); flush_queue_.pop_front(); if (!immutable_db_options_.atomic_flush) { assert(flush_req.cfd_to_max_mem_id_to_persist.size() == 1); } for (const auto& elem : flush_req.cfd_to_max_mem_id_to_persist) { if (!immutable_db_options_.atomic_flush) { ColumnFamilyData* cfd = elem.first; assert(cfd); assert(cfd->queued_for_flush()); cfd->set_queued_for_flush(false); } } return flush_req; } ColumnFamilyData* DBImpl::PickCompactionFromQueue( std::unique_ptr* token, LogBuffer* log_buffer) { assert(!compaction_queue_.empty()); assert(*token == nullptr); autovector throttled_candidates; ColumnFamilyData* cfd = nullptr; while (!compaction_queue_.empty()) { auto first_cfd = *compaction_queue_.begin(); compaction_queue_.pop_front(); assert(first_cfd->queued_for_compaction()); if (!RequestCompactionToken(first_cfd, false, token, log_buffer)) { throttled_candidates.push_back(first_cfd); continue; } cfd = first_cfd; cfd->set_queued_for_compaction(false); break; } // Add throttled compaction candidates back to queue in the original order. for (auto iter = throttled_candidates.rbegin(); iter != throttled_candidates.rend(); ++iter) { compaction_queue_.push_front(*iter); } return cfd; } void DBImpl::SchedulePendingFlush(const FlushRequest& flush_req) { mutex_.AssertHeld(); if (flush_req.cfd_to_max_mem_id_to_persist.empty()) { return; } if (!immutable_db_options_.atomic_flush) { // For the non-atomic flush case, we never schedule multiple column // families in the same flush request. assert(flush_req.cfd_to_max_mem_id_to_persist.size() == 1); ColumnFamilyData* cfd = flush_req.cfd_to_max_mem_id_to_persist.begin()->first; assert(cfd); if (!cfd->queued_for_flush() && cfd->imm()->IsFlushPending()) { cfd->Ref(); cfd->set_queued_for_flush(true); ++unscheduled_flushes_; flush_queue_.push_back(flush_req); } } else { for (auto& iter : flush_req.cfd_to_max_mem_id_to_persist) { ColumnFamilyData* cfd = iter.first; cfd->Ref(); } ++unscheduled_flushes_; flush_queue_.push_back(flush_req); } } void DBImpl::SchedulePendingCompaction(ColumnFamilyData* cfd) { mutex_.AssertHeld(); if (!cfd->queued_for_compaction() && cfd->NeedsCompaction()) { AddToCompactionQueue(cfd); ++unscheduled_compactions_; } } void DBImpl::SchedulePendingPurge(std::string fname, std::string dir_to_sync, FileType type, uint64_t number, int job_id) { mutex_.AssertHeld(); PurgeFileInfo file_info(fname, dir_to_sync, type, number, job_id); purge_files_.insert({{number, std::move(file_info)}}); } void DBImpl::BGWorkFlush(void* arg) { FlushThreadArg fta = *(reinterpret_cast(arg)); delete reinterpret_cast(arg); IOSTATS_SET_THREAD_POOL_ID(fta.thread_pri_); TEST_SYNC_POINT("DBImpl::BGWorkFlush"); static_cast_with_check(fta.db_)->BackgroundCallFlush(fta.thread_pri_); TEST_SYNC_POINT("DBImpl::BGWorkFlush:done"); } void DBImpl::BGWorkCompaction(void* arg) { CompactionArg ca = *(reinterpret_cast(arg)); delete reinterpret_cast(arg); IOSTATS_SET_THREAD_POOL_ID(Env::Priority::LOW); TEST_SYNC_POINT("DBImpl::BGWorkCompaction"); auto prepicked_compaction = static_cast(ca.prepicked_compaction); static_cast_with_check(ca.db)->BackgroundCallCompaction( prepicked_compaction, Env::Priority::LOW); delete prepicked_compaction; } void DBImpl::BGWorkBottomCompaction(void* arg) { CompactionArg ca = *(static_cast(arg)); delete static_cast(arg); IOSTATS_SET_THREAD_POOL_ID(Env::Priority::BOTTOM); TEST_SYNC_POINT("DBImpl::BGWorkBottomCompaction"); auto* prepicked_compaction = ca.prepicked_compaction; assert(prepicked_compaction && prepicked_compaction->compaction); ca.db->BackgroundCallCompaction(prepicked_compaction, Env::Priority::BOTTOM); delete prepicked_compaction; } void DBImpl::BGWorkPurge(void* db) { IOSTATS_SET_THREAD_POOL_ID(Env::Priority::LOW); TEST_SYNC_POINT("DBImpl::BGWorkPurge:start"); reinterpret_cast(db)->BackgroundCallPurge(); TEST_SYNC_POINT("DBImpl::BGWorkPurge:end"); } void DBImpl::UnscheduleCompactionCallback(void* arg) { CompactionArg* ca_ptr = reinterpret_cast(arg); Env::Priority compaction_pri = ca_ptr->compaction_pri_; if (Env::Priority::BOTTOM == compaction_pri) { // Decrement bg_bottom_compaction_scheduled_ if priority is BOTTOM ca_ptr->db->bg_bottom_compaction_scheduled_--; } else if (Env::Priority::LOW == compaction_pri) { // Decrement bg_compaction_scheduled_ if priority is LOW ca_ptr->db->bg_compaction_scheduled_--; } CompactionArg ca = *(ca_ptr); delete reinterpret_cast(arg); if (ca.prepicked_compaction != nullptr) { // if it's a manual compaction, set status to ManualCompactionPaused if (ca.prepicked_compaction->manual_compaction_state) { ca.prepicked_compaction->manual_compaction_state->done = true; ca.prepicked_compaction->manual_compaction_state->status = Status::Incomplete(Status::SubCode::kManualCompactionPaused); } if (ca.prepicked_compaction->compaction != nullptr) { ca.prepicked_compaction->compaction->ReleaseCompactionFiles( Status::Incomplete(Status::SubCode::kManualCompactionPaused)); delete ca.prepicked_compaction->compaction; } delete ca.prepicked_compaction; } TEST_SYNC_POINT("DBImpl::UnscheduleCompactionCallback"); } void DBImpl::UnscheduleFlushCallback(void* arg) { // Decrement bg_flush_scheduled_ in flush callback reinterpret_cast(arg)->db_->bg_flush_scheduled_--; Env::Priority flush_pri = reinterpret_cast(arg)->thread_pri_; if (Env::Priority::LOW == flush_pri) { TEST_SYNC_POINT("DBImpl::UnscheduleLowFlushCallback"); } else if (Env::Priority::HIGH == flush_pri) { TEST_SYNC_POINT("DBImpl::UnscheduleHighFlushCallback"); } delete reinterpret_cast(arg); TEST_SYNC_POINT("DBImpl::UnscheduleFlushCallback"); } Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, FlushReason* reason, Env::Priority thread_pri) { mutex_.AssertHeld(); Status status; *reason = FlushReason::kOthers; // If BG work is stopped due to an error, but a recovery is in progress, // that means this flush is part of the recovery. So allow it to go through if (!error_handler_.IsBGWorkStopped()) { if (shutting_down_.load(std::memory_order_acquire)) { status = Status::ShutdownInProgress(); } } else if (!error_handler_.IsRecoveryInProgress()) { status = error_handler_.GetBGError(); } if (!status.ok()) { return status; } autovector bg_flush_args; std::vector& superversion_contexts = job_context->superversion_contexts; autovector column_families_not_to_flush; while (!flush_queue_.empty()) { // This cfd is already referenced const FlushRequest& flush_req = PopFirstFromFlushQueue(); FlushReason flush_reason = flush_req.flush_reason; superversion_contexts.clear(); superversion_contexts.reserve( flush_req.cfd_to_max_mem_id_to_persist.size()); for (const auto& iter : flush_req.cfd_to_max_mem_id_to_persist) { ColumnFamilyData* cfd = iter.first; if (cfd->GetMempurgeUsed()) { // If imm() contains silent memtables (e.g.: because // MemPurge was activated), requesting a flush will // mark the imm_needed as true. cfd->imm()->FlushRequested(); } if (cfd->IsDropped() || !cfd->imm()->IsFlushPending()) { // can't flush this CF, try next one column_families_not_to_flush.push_back(cfd); continue; } superversion_contexts.emplace_back(SuperVersionContext(true)); bg_flush_args.emplace_back(cfd, iter.second, &(superversion_contexts.back()), flush_reason); } if (!bg_flush_args.empty()) { break; } } if (!bg_flush_args.empty()) { auto bg_job_limits = GetBGJobLimits(); for (const auto& arg : bg_flush_args) { ColumnFamilyData* cfd = arg.cfd_; ROCKS_LOG_BUFFER( log_buffer, "Calling FlushMemTableToOutputFile with column " "family [%s], flush slots available %d, compaction slots available " "%d, " "flush slots scheduled %d, compaction slots scheduled %d", cfd->GetName().c_str(), bg_job_limits.max_flushes, bg_job_limits.max_compactions, bg_flush_scheduled_, bg_compaction_scheduled_); } *reason = bg_flush_args[0].flush_reason_; if (write_buffer_manager_) { write_buffer_manager_->FlushStarted( *reason == FlushReason::kWriteBufferManagerInitiated); } status = FlushMemTablesToOutputFiles(bg_flush_args, made_progress, job_context, log_buffer, thread_pri); TEST_SYNC_POINT("DBImpl::BackgroundFlush:BeforeFlush"); // All the CFD/bg_flush_arg in the FlushReq must have the same flush reason, so // just grab the first one #ifndef NDEBUG for (const auto& bg_flush_arg : bg_flush_args) { assert(bg_flush_arg.flush_reason_ == bg_flush_args[0].flush_reason_); } #endif /* !NDEBUG */ for (auto& arg : bg_flush_args) { ColumnFamilyData* cfd = arg.cfd_; if (cfd->UnrefAndTryDelete()) { arg.cfd_ = nullptr; } } } for (auto cfd : column_families_not_to_flush) { cfd->UnrefAndTryDelete(); } return status; } void DBImpl::BackgroundCallFlush(Env::Priority thread_pri) { bool made_progress = false; JobContext job_context(next_job_id_.fetch_add(1), true); TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCallFlush:start", nullptr); LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, immutable_db_options_.info_log.get()); TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:Start:1"); TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:Start:2"); { InstrumentedMutexLock l(&mutex_); assert(bg_flush_scheduled_); num_running_flushes_++; std::unique_ptr::iterator> pending_outputs_inserted_elem(new std::list::iterator( CaptureCurrentFileNumberInPendingOutputs())); FlushReason reason; Status s = BackgroundFlush(&made_progress, &job_context, &log_buffer, &reason, thread_pri); if (!s.ok() && !s.IsShutdownInProgress() && !s.IsColumnFamilyDropped() && reason != FlushReason::kErrorRecovery) { // Wait a little bit before retrying background flush in // case this is an environmental problem and we do not want to // chew up resources for failed flushes for the duration of // the problem. uint64_t error_cnt = default_cf_internal_stats_->BumpAndGetBackgroundErrorCount(); bg_cv_.SignalAll(); // In case a waiter can proceed despite the error mutex_.Unlock(); ROCKS_LOG_ERROR(immutable_db_options_.info_log, "Waiting after background flush error: %s" "Accumulated background error counts: %" PRIu64, s.ToString().c_str(), error_cnt); log_buffer.FlushBufferToLog(); LogFlush(immutable_db_options_.info_log); immutable_db_options_.clock->SleepForMicroseconds(1000000); mutex_.Lock(); } TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:FlushFinish:0"); ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem); // If flush failed, we want to delete all temporary files that we might have // created. Thus, we force full scan in FindObsoleteFiles() FindObsoleteFiles(&job_context, !s.ok() && !s.IsShutdownInProgress() && !s.IsColumnFamilyDropped()); // delete unnecessary files if any, this is done outside the mutex if (job_context.HaveSomethingToClean() || job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) { mutex_.Unlock(); TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:FilesFound"); // Have to flush the info logs before bg_flush_scheduled_-- // because if bg_flush_scheduled_ becomes 0 and the lock is // released, the deconstructor of DB can kick in and destroy all the // states of DB so info_log might not be available after that point. // It also applies to access other states that DB owns. log_buffer.FlushBufferToLog(); if (job_context.HaveSomethingToDelete()) { PurgeObsoleteFiles(job_context); } job_context.Clean(); mutex_.Lock(); } TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:ContextCleanedUp"); assert(num_running_flushes_ > 0); num_running_flushes_--; bg_flush_scheduled_--; if (write_buffer_manager_) { write_buffer_manager_->FlushEnded( reason == FlushReason::kWriteBufferManagerInitiated); } // See if there's more work to be done MaybeScheduleFlushOrCompaction(); atomic_flush_install_cv_.SignalAll(); bg_cv_.SignalAll(); // IMPORTANT: there should be no code after calling SignalAll. This call may // signal the DB destructor that it's OK to proceed with destruction. In // that case, all DB variables will be dealloacated and referencing them // will cause trouble. } } void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction, Env::Priority bg_thread_pri) { bool made_progress = false; JobContext job_context(next_job_id_.fetch_add(1), true); TEST_SYNC_POINT("BackgroundCallCompaction:0"); LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, immutable_db_options_.info_log.get()); { InstrumentedMutexLock l(&mutex_); num_running_compactions_++; std::unique_ptr::iterator> pending_outputs_inserted_elem(new std::list::iterator( CaptureCurrentFileNumberInPendingOutputs())); assert((bg_thread_pri == Env::Priority::BOTTOM && bg_bottom_compaction_scheduled_) || (bg_thread_pri == Env::Priority::LOW && bg_compaction_scheduled_)); Status s = BackgroundCompaction(&made_progress, &job_context, &log_buffer, prepicked_compaction, bg_thread_pri); TEST_SYNC_POINT("BackgroundCallCompaction:1"); if (s.IsBusy()) { bg_cv_.SignalAll(); // In case a waiter can proceed despite the error mutex_.Unlock(); immutable_db_options_.clock->SleepForMicroseconds( 10000); // prevent hot loop mutex_.Lock(); } else if (!s.ok() && !s.IsShutdownInProgress() && !s.IsManualCompactionPaused() && !s.IsColumnFamilyDropped()) { // Wait a little bit before retrying background compaction in // case this is an environmental problem and we do not want to // chew up resources for failed compactions for the duration of // the problem. uint64_t error_cnt = default_cf_internal_stats_->BumpAndGetBackgroundErrorCount(); bg_cv_.SignalAll(); // In case a waiter can proceed despite the error mutex_.Unlock(); log_buffer.FlushBufferToLog(); ROCKS_LOG_ERROR(immutable_db_options_.info_log, "Waiting after background compaction error: %s, " "Accumulated background error counts: %" PRIu64, s.ToString().c_str(), error_cnt); LogFlush(immutable_db_options_.info_log); immutable_db_options_.clock->SleepForMicroseconds(1000000); mutex_.Lock(); } else if (s.IsManualCompactionPaused()) { assert(prepicked_compaction); ManualCompactionState* m = prepicked_compaction->manual_compaction_state; assert(m); ROCKS_LOG_BUFFER(&log_buffer, "[%s] [JOB %d] Manual compaction paused", m->cfd->GetName().c_str(), job_context.job_id); } ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem); // If compaction failed, we want to delete all temporary files that we // might have created (they might not be all recorded in job_context in // case of a failure). Thus, we force full scan in FindObsoleteFiles() FindObsoleteFiles(&job_context, !s.ok() && !s.IsShutdownInProgress() && !s.IsManualCompactionPaused() && !s.IsColumnFamilyDropped() && !s.IsBusy()); TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:FoundObsoleteFiles"); // delete unnecessary files if any, this is done outside the mutex if (job_context.HaveSomethingToClean() || job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) { mutex_.Unlock(); // Have to flush the info logs before bg_compaction_scheduled_-- // because if bg_flush_scheduled_ becomes 0 and the lock is // released, the deconstructor of DB can kick in and destroy all the // states of DB so info_log might not be available after that point. // It also applies to access other states that DB owns. log_buffer.FlushBufferToLog(); if (job_context.HaveSomethingToDelete()) { PurgeObsoleteFiles(job_context); TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles"); } job_context.Clean(); mutex_.Lock(); } assert(num_running_compactions_ > 0); num_running_compactions_--; if (bg_thread_pri == Env::Priority::LOW) { bg_compaction_scheduled_--; } else { assert(bg_thread_pri == Env::Priority::BOTTOM); bg_bottom_compaction_scheduled_--; } // See if there's more work to be done MaybeScheduleFlushOrCompaction(); if (prepicked_compaction != nullptr && prepicked_compaction->task_token != nullptr) { // Releasing task tokens affects (and asserts on) the DB state, so // must be done before we potentially signal the DB close process to // proceed below. prepicked_compaction->task_token.reset(); } if (made_progress || (bg_compaction_scheduled_ == 0 && bg_bottom_compaction_scheduled_ == 0) || HasPendingManualCompaction() || unscheduled_compactions_ == 0) { // signal if // * made_progress -- need to wakeup DelayWrite // * bg_{bottom,}_compaction_scheduled_ == 0 -- need to wakeup ~DBImpl // * HasPendingManualCompaction -- need to wakeup RunManualCompaction // If none of this is true, there is no need to signal since nobody is // waiting for it bg_cv_.SignalAll(); } // IMPORTANT: there should be no code after calling SignalAll. This call may // signal the DB destructor that it's OK to proceed with destruction. In // that case, all DB variables will be dealloacated and referencing them // will cause trouble. } } Status DBImpl::BackgroundCompaction(bool* made_progress, JobContext* job_context, LogBuffer* log_buffer, PrepickedCompaction* prepicked_compaction, Env::Priority thread_pri) { ManualCompactionState* manual_compaction = prepicked_compaction == nullptr ? nullptr : prepicked_compaction->manual_compaction_state; *made_progress = false; mutex_.AssertHeld(); TEST_SYNC_POINT("DBImpl::BackgroundCompaction:Start"); bool is_manual = (manual_compaction != nullptr); std::unique_ptr c; if (prepicked_compaction != nullptr && prepicked_compaction->compaction != nullptr) { c.reset(prepicked_compaction->compaction); } bool is_prepicked = is_manual || c; // (manual_compaction->in_progress == false); bool trivial_move_disallowed = is_manual && manual_compaction->disallow_trivial_move; CompactionJobStats compaction_job_stats; Status status; if (!error_handler_.IsBGWorkStopped()) { if (shutting_down_.load(std::memory_order_acquire)) { status = Status::ShutdownInProgress(); } else if (is_manual && manual_compaction->canceled.load(std::memory_order_acquire)) { status = Status::Incomplete(Status::SubCode::kManualCompactionPaused); } } else { status = error_handler_.GetBGError(); // If we get here, it means a hard error happened after this compaction // was scheduled by MaybeScheduleFlushOrCompaction(), but before it got // a chance to execute. Since we didn't pop a cfd from the compaction // queue, increment unscheduled_compactions_ unscheduled_compactions_++; } if (!status.ok()) { if (is_manual) { manual_compaction->status = status; manual_compaction->done = true; manual_compaction->in_progress = false; manual_compaction = nullptr; } if (c) { c->ReleaseCompactionFiles(status); c.reset(); } return status; } if (is_manual) { // another thread cannot pick up the same work manual_compaction->in_progress = true; } TEST_SYNC_POINT("DBImpl::BackgroundCompaction:InProgress"); std::unique_ptr task_token; // InternalKey manual_end_storage; // InternalKey* manual_end = &manual_end_storage; bool sfm_reserved_compact_space = false; if (is_manual) { ManualCompactionState* m = manual_compaction; assert(m->in_progress); if (!c) { m->done = true; m->manual_end = nullptr; ROCKS_LOG_BUFFER( log_buffer, "[%s] Manual compaction from level-%d from %s .. " "%s; nothing to do\n", m->cfd->GetName().c_str(), m->input_level, (m->begin ? m->begin->DebugString(true).c_str() : "(begin)"), (m->end ? m->end->DebugString(true).c_str() : "(end)")); } else { // First check if we have enough room to do the compaction bool enough_room = EnoughRoomForCompaction( m->cfd, *(c->inputs()), &sfm_reserved_compact_space, log_buffer); if (!enough_room) { // Then don't do the compaction c->ReleaseCompactionFiles(status); c.reset(); // m's vars will get set properly at the end of this function, // as long as status == CompactionTooLarge status = Status::CompactionTooLarge(); } else { ROCKS_LOG_BUFFER( log_buffer, "[%s] Manual compaction from level-%d to level-%d from %s .. " "%s; will stop at %s\n", m->cfd->GetName().c_str(), m->input_level, c->output_level(), (m->begin ? m->begin->DebugString(true).c_str() : "(begin)"), (m->end ? m->end->DebugString(true).c_str() : "(end)"), ((m->done || m->manual_end == nullptr) ? "(end)" : m->manual_end->DebugString(true).c_str())); } } } else if (!is_prepicked && !compaction_queue_.empty()) { if (HasExclusiveManualCompaction()) { // Can't compact right now, but try again later TEST_SYNC_POINT("DBImpl::BackgroundCompaction()::Conflict"); // Stay in the compaction queue. unscheduled_compactions_++; return Status::OK(); } auto cfd = PickCompactionFromQueue(&task_token, log_buffer); if (cfd == nullptr) { // Can't find any executable task from the compaction queue. // All tasks have been throttled by compaction thread limiter. ++unscheduled_compactions_; return Status::Busy(); } // We unreference here because the following code will take a Ref() on // this cfd if it is going to use it (Compaction class holds a // reference). // This will all happen under a mutex so we don't have to be afraid of // somebody else deleting it. if (cfd->UnrefAndTryDelete()) { // This was the last reference of the column family, so no need to // compact. return Status::OK(); } // Pick up latest mutable CF Options and use it throughout the // compaction job // Compaction makes a copy of the latest MutableCFOptions. It should be used // throughout the compaction procedure to make sure consistency. It will // eventually be installed into SuperVersion auto* mutable_cf_options = cfd->GetLatestMutableCFOptions(); if (!mutable_cf_options->disable_auto_compactions && !cfd->IsDropped()) { // NOTE: try to avoid unnecessary copy of MutableCFOptions if // compaction is not necessary. Need to make sure mutex is held // until we make a copy in the following code TEST_SYNC_POINT("DBImpl::BackgroundCompaction():BeforePickCompaction"); c.reset(cfd->PickCompaction(*mutable_cf_options, mutable_db_options_, log_buffer)); TEST_SYNC_POINT("DBImpl::BackgroundCompaction():AfterPickCompaction"); if (c != nullptr) { bool enough_room = EnoughRoomForCompaction( cfd, *(c->inputs()), &sfm_reserved_compact_space, log_buffer); if (!enough_room) { // Then don't do the compaction c->ReleaseCompactionFiles(status); c->column_family_data() ->current() ->storage_info() ->ComputeCompactionScore(*(c->immutable_options()), *(c->mutable_cf_options())); AddToCompactionQueue(cfd); ++unscheduled_compactions_; c.reset(); // Don't need to sleep here, because BackgroundCallCompaction // will sleep if !s.ok() status = Status::CompactionTooLarge(); } else { // update statistics size_t num_files = 0; for (auto& each_level : *c->inputs()) { num_files += each_level.files.size(); } RecordInHistogram(stats_, NUM_FILES_IN_SINGLE_COMPACTION, num_files); // There are three things that can change compaction score: // 1) When flush or compaction finish. This case is covered by // InstallSuperVersionAndScheduleWork // 2) When MutableCFOptions changes. This case is also covered by // InstallSuperVersionAndScheduleWork, because this is when the new // options take effect. // 3) When we Pick a new compaction, we "remove" those files being // compacted from the calculation, which then influences compaction // score. Here we check if we need the new compaction even without the // files that are currently being compacted. If we need another // compaction, we might be able to execute it in parallel, so we add // it to the queue and schedule a new thread. if (cfd->NeedsCompaction()) { // Yes, we need more compactions! AddToCompactionQueue(cfd); ++unscheduled_compactions_; MaybeScheduleFlushOrCompaction(); } } } } } IOStatus io_s; if (!c) { // Nothing to do ROCKS_LOG_BUFFER(log_buffer, "Compaction nothing to do"); } else if (c->deletion_compaction()) { // TODO(icanadi) Do we want to honor snapshots here? i.e. not delete old // file if there is alive snapshot pointing to it TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:BeforeCompaction", c->column_family_data()); assert(c->num_input_files(1) == 0); assert(c->column_family_data()->ioptions()->compaction_style == kCompactionStyleFIFO); compaction_job_stats.num_input_files = c->num_input_files(0); NotifyOnCompactionBegin(c->column_family_data(), c.get(), status, compaction_job_stats, job_context->job_id); for (const auto& f : *c->inputs(0)) { c->edit()->DeleteFile(c->level(), f->fd.GetNumber()); } status = versions_->LogAndApply(c->column_family_data(), *c->mutable_cf_options(), c->edit(), &mutex_, directories_.GetDbDir()); io_s = versions_->io_status(); InstallSuperVersionAndScheduleWork(c->column_family_data(), &job_context->superversion_contexts[0], *c->mutable_cf_options()); ROCKS_LOG_BUFFER(log_buffer, "[%s] Deleted %d files\n", c->column_family_data()->GetName().c_str(), c->num_input_files(0)); *made_progress = true; TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:AfterCompaction", c->column_family_data()); } else if (!trivial_move_disallowed && c->IsTrivialMove()) { TEST_SYNC_POINT("DBImpl::BackgroundCompaction:TrivialMove"); TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:BeforeCompaction", c->column_family_data()); // Instrument for event update // TODO(yhchiang): add op details for showing trivial-move. ThreadStatusUtil::SetColumnFamily( c->column_family_data(), c->column_family_data()->ioptions()->env, immutable_db_options_.enable_thread_tracking); ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION); compaction_job_stats.num_input_files = c->num_input_files(0); NotifyOnCompactionBegin(c->column_family_data(), c.get(), status, compaction_job_stats, job_context->job_id); // Move files to next level int32_t moved_files = 0; int64_t moved_bytes = 0; for (unsigned int l = 0; l < c->num_input_levels(); l++) { if (c->level(l) == c->output_level()) { continue; } for (size_t i = 0; i < c->num_input_files(l); i++) { FileMetaData* f = c->input(l, i); c->edit()->DeleteFile(c->level(l), f->fd.GetNumber()); c->edit()->AddFile( c->output_level(), f->fd.GetNumber(), f->fd.GetPathId(), f->fd.GetFileSize(), f->smallest, f->largest, f->fd.smallest_seqno, f->fd.largest_seqno, f->marked_for_compaction, f->temperature, f->oldest_blob_file_number, f->oldest_ancester_time, f->file_creation_time, f->epoch_number, f->file_checksum, f->file_checksum_func_name, f->unique_id, f->compensated_range_deletion_size); ROCKS_LOG_BUFFER( log_buffer, "[%s] Moving #%" PRIu64 " to level-%d %" PRIu64 " bytes\n", c->column_family_data()->GetName().c_str(), f->fd.GetNumber(), c->output_level(), f->fd.GetFileSize()); ++moved_files; moved_bytes += f->fd.GetFileSize(); } } if (c->compaction_reason() == CompactionReason::kLevelMaxLevelSize && c->immutable_options()->compaction_pri == kRoundRobin) { int start_level = c->start_level(); if (start_level > 0) { auto vstorage = c->input_version()->storage_info(); c->edit()->AddCompactCursor( start_level, vstorage->GetNextCompactCursor(start_level, c->num_input_files(0))); } } status = versions_->LogAndApply(c->column_family_data(), *c->mutable_cf_options(), c->edit(), &mutex_, directories_.GetDbDir()); io_s = versions_->io_status(); // Use latest MutableCFOptions InstallSuperVersionAndScheduleWork(c->column_family_data(), &job_context->superversion_contexts[0], *c->mutable_cf_options()); VersionStorageInfo::LevelSummaryStorage tmp; c->column_family_data()->internal_stats()->IncBytesMoved(c->output_level(), moved_bytes); { event_logger_.LogToBuffer(log_buffer) << "job" << job_context->job_id << "event" << "trivial_move" << "destination_level" << c->output_level() << "files" << moved_files << "total_files_size" << moved_bytes; } ROCKS_LOG_BUFFER( log_buffer, "[%s] Moved #%d files to level-%d %" PRIu64 " bytes %s: %s\n", c->column_family_data()->GetName().c_str(), moved_files, c->output_level(), moved_bytes, status.ToString().c_str(), c->column_family_data()->current()->storage_info()->LevelSummary(&tmp)); *made_progress = true; // Clear Instrument ThreadStatusUtil::ResetThreadStatus(); TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:AfterCompaction", c->column_family_data()); } else if (!is_prepicked && c->output_level() > 0 && c->output_level() == c->column_family_data() ->current() ->storage_info() ->MaxOutputLevel( immutable_db_options_.allow_ingest_behind) && env_->GetBackgroundThreads(Env::Priority::BOTTOM) > 0) { // Forward compactions involving last level to the bottom pool if it exists, // such that compactions unlikely to contribute to write stalls can be // delayed or deprioritized. TEST_SYNC_POINT("DBImpl::BackgroundCompaction:ForwardToBottomPriPool"); CompactionArg* ca = new CompactionArg; ca->db = this; ca->compaction_pri_ = Env::Priority::BOTTOM; ca->prepicked_compaction = new PrepickedCompaction; ca->prepicked_compaction->compaction = c.release(); ca->prepicked_compaction->manual_compaction_state = nullptr; // Transfer requested token, so it doesn't need to do it again. ca->prepicked_compaction->task_token = std::move(task_token); ++bg_bottom_compaction_scheduled_; env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca, Env::Priority::BOTTOM, this, &DBImpl::UnscheduleCompactionCallback); } else { TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:BeforeCompaction", c->column_family_data()); int output_level __attribute__((__unused__)); output_level = c->output_level(); TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:NonTrivial", &output_level); std::vector snapshot_seqs; SequenceNumber earliest_write_conflict_snapshot; SnapshotChecker* snapshot_checker; GetSnapshotContext(job_context, &snapshot_seqs, &earliest_write_conflict_snapshot, &snapshot_checker); assert(is_snapshot_supported_ || snapshots_.empty()); CompactionJob compaction_job( job_context->job_id, c.get(), immutable_db_options_, mutable_db_options_, file_options_for_compaction_, versions_.get(), &shutting_down_, log_buffer, directories_.GetDbDir(), GetDataDir(c->column_family_data(), c->output_path_id()), GetDataDir(c->column_family_data(), 0), stats_, &mutex_, &error_handler_, snapshot_seqs, earliest_write_conflict_snapshot, snapshot_checker, job_context, table_cache_, &event_logger_, c->mutable_cf_options()->paranoid_file_checks, c->mutable_cf_options()->report_bg_io_stats, dbname_, &compaction_job_stats, thread_pri, io_tracer_, is_manual ? manual_compaction->canceled : kManualCompactionCanceledFalse_, db_id_, db_session_id_, c->column_family_data()->GetFullHistoryTsLow(), c->trim_ts(), &blob_callback_, &bg_compaction_scheduled_, &bg_bottom_compaction_scheduled_); compaction_job.Prepare(); NotifyOnCompactionBegin(c->column_family_data(), c.get(), status, compaction_job_stats, job_context->job_id); mutex_.Unlock(); TEST_SYNC_POINT_CALLBACK( "DBImpl::BackgroundCompaction:NonTrivial:BeforeRun", nullptr); // Should handle erorr? compaction_job.Run().PermitUncheckedError(); TEST_SYNC_POINT("DBImpl::BackgroundCompaction:NonTrivial:AfterRun"); mutex_.Lock(); status = compaction_job.Install(*c->mutable_cf_options()); io_s = compaction_job.io_status(); if (status.ok()) { InstallSuperVersionAndScheduleWork(c->column_family_data(), &job_context->superversion_contexts[0], *c->mutable_cf_options()); } *made_progress = true; TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:AfterCompaction", c->column_family_data()); } if (status.ok() && !io_s.ok()) { status = io_s; } else { io_s.PermitUncheckedError(); } if (c != nullptr) { c->ReleaseCompactionFiles(status); *made_progress = true; // Need to make sure SstFileManager does its bookkeeping auto sfm = static_cast( immutable_db_options_.sst_file_manager.get()); if (sfm && sfm_reserved_compact_space) { sfm->OnCompactionCompletion(c.get()); } NotifyOnCompactionCompleted(c->column_family_data(), c.get(), status, compaction_job_stats, job_context->job_id); } if (status.ok() || status.IsCompactionTooLarge() || status.IsManualCompactionPaused()) { // Done } else if (status.IsColumnFamilyDropped() || status.IsShutdownInProgress()) { // Ignore compaction errors found during shutting down } else { ROCKS_LOG_WARN(immutable_db_options_.info_log, "Compaction error: %s", status.ToString().c_str()); if (!io_s.ok()) { // Error while writing to MANIFEST. // In fact, versions_->io_status() can also be the result of renaming // CURRENT file. With current code, it's just difficult to tell. So just // be pessimistic and try write to a new MANIFEST. // TODO: distinguish between MANIFEST write and CURRENT renaming auto err_reason = versions_->io_status().ok() ? BackgroundErrorReason::kCompaction : BackgroundErrorReason::kManifestWrite; error_handler_.SetBGError(io_s, err_reason); } else { error_handler_.SetBGError(status, BackgroundErrorReason::kCompaction); } if (c != nullptr && !is_manual && !error_handler_.IsBGWorkStopped()) { // Put this cfd back in the compaction queue so we can retry after some // time auto cfd = c->column_family_data(); assert(cfd != nullptr); // Since this compaction failed, we need to recompute the score so it // takes the original input files into account c->column_family_data() ->current() ->storage_info() ->ComputeCompactionScore(*(c->immutable_options()), *(c->mutable_cf_options())); if (!cfd->queued_for_compaction()) { AddToCompactionQueue(cfd); ++unscheduled_compactions_; } } } // this will unref its input_version and column_family_data c.reset(); if (is_manual) { ManualCompactionState* m = manual_compaction; if (!status.ok()) { m->status = status; m->done = true; } // For universal compaction: // Because universal compaction always happens at level 0, so one // compaction will pick up all overlapped files. No files will be // filtered out due to size limit and left for a successive compaction. // So we can safely conclude the current compaction. // // Also note that, if we don't stop here, then the current compaction // writes a new file back to level 0, which will be used in successive // compaction. Hence the manual compaction will never finish. // // Stop the compaction if manual_end points to nullptr -- this means // that we compacted the whole range. manual_end should always point // to nullptr in case of universal compaction if (m->manual_end == nullptr) { m->done = true; } if (!m->done) { // We only compacted part of the requested range. Update *m // to the range that is left to be compacted. // Universal and FIFO compactions should always compact the whole range assert(m->cfd->ioptions()->compaction_style != kCompactionStyleUniversal || m->cfd->ioptions()->num_levels > 1); assert(m->cfd->ioptions()->compaction_style != kCompactionStyleFIFO); m->tmp_storage = *m->manual_end; m->begin = &m->tmp_storage; m->incomplete = true; } m->in_progress = false; // not being processed anymore } TEST_SYNC_POINT("DBImpl::BackgroundCompaction:Finish"); return status; } bool DBImpl::HasPendingManualCompaction() { return (!manual_compaction_dequeue_.empty()); } void DBImpl::AddManualCompaction(DBImpl::ManualCompactionState* m) { assert(manual_compaction_paused_ == 0); manual_compaction_dequeue_.push_back(m); } void DBImpl::RemoveManualCompaction(DBImpl::ManualCompactionState* m) { // Remove from queue std::deque::iterator it = manual_compaction_dequeue_.begin(); while (it != manual_compaction_dequeue_.end()) { if (m == (*it)) { it = manual_compaction_dequeue_.erase(it); return; } ++it; } assert(false); return; } bool DBImpl::ShouldntRunManualCompaction(ManualCompactionState* m) { if (m->exclusive) { return (bg_bottom_compaction_scheduled_ > 0 || bg_compaction_scheduled_ > 0); } std::deque::iterator it = manual_compaction_dequeue_.begin(); bool seen = false; while (it != manual_compaction_dequeue_.end()) { if (m == (*it)) { ++it; seen = true; continue; } else if (MCOverlap(m, (*it)) && (!seen && !(*it)->in_progress)) { // Consider the other manual compaction *it, conflicts if: // overlaps with m // and (*it) is ahead in the queue and is not yet in progress return true; } ++it; } return false; } bool DBImpl::HaveManualCompaction(ColumnFamilyData* cfd) { // Remove from priority queue std::deque::iterator it = manual_compaction_dequeue_.begin(); while (it != manual_compaction_dequeue_.end()) { if ((*it)->exclusive) { return true; } if ((cfd == (*it)->cfd) && (!((*it)->in_progress || (*it)->done))) { // Allow automatic compaction if manual compaction is // in progress return true; } ++it; } return false; } bool DBImpl::HasExclusiveManualCompaction() { // Remove from priority queue std::deque::iterator it = manual_compaction_dequeue_.begin(); while (it != manual_compaction_dequeue_.end()) { if ((*it)->exclusive) { return true; } ++it; } return false; } bool DBImpl::MCOverlap(ManualCompactionState* m, ManualCompactionState* m1) { if ((m->exclusive) || (m1->exclusive)) { return true; } if (m->cfd != m1->cfd) { return false; } return false; } void DBImpl::BuildCompactionJobInfo( const ColumnFamilyData* cfd, Compaction* c, const Status& st, const CompactionJobStats& compaction_job_stats, const int job_id, const Version* current, CompactionJobInfo* compaction_job_info) const { assert(compaction_job_info != nullptr); compaction_job_info->cf_id = cfd->GetID(); compaction_job_info->cf_name = cfd->GetName(); compaction_job_info->status = st; compaction_job_info->thread_id = env_->GetThreadID(); compaction_job_info->job_id = job_id; compaction_job_info->base_input_level = c->start_level(); compaction_job_info->output_level = c->output_level(); compaction_job_info->stats = compaction_job_stats; compaction_job_info->table_properties = c->GetOutputTableProperties(); compaction_job_info->compaction_reason = c->compaction_reason(); compaction_job_info->compression = c->output_compression(); for (size_t i = 0; i < c->num_input_levels(); ++i) { for (const auto fmd : *c->inputs(i)) { const FileDescriptor& desc = fmd->fd; const uint64_t file_number = desc.GetNumber(); auto fn = TableFileName(c->immutable_options()->cf_paths, file_number, desc.GetPathId()); compaction_job_info->input_files.push_back(fn); compaction_job_info->input_file_infos.push_back(CompactionFileInfo{ static_cast(i), file_number, fmd->oldest_blob_file_number}); if (compaction_job_info->table_properties.count(fn) == 0) { std::shared_ptr tp; auto s = current->GetTableProperties(&tp, fmd, &fn); if (s.ok()) { compaction_job_info->table_properties[fn] = tp; } } } } for (const auto& newf : c->edit()->GetNewFiles()) { const FileMetaData& meta = newf.second; const FileDescriptor& desc = meta.fd; const uint64_t file_number = desc.GetNumber(); compaction_job_info->output_files.push_back(TableFileName( c->immutable_options()->cf_paths, file_number, desc.GetPathId())); compaction_job_info->output_file_infos.push_back(CompactionFileInfo{ newf.first, file_number, meta.oldest_blob_file_number}); } compaction_job_info->blob_compression_type = c->mutable_cf_options()->blob_compression_type; // Update BlobFilesInfo. for (const auto& blob_file : c->edit()->GetBlobFileAdditions()) { BlobFileAdditionInfo blob_file_addition_info( BlobFileName(c->immutable_options()->cf_paths.front().path, blob_file.GetBlobFileNumber()) /*blob_file_path*/, blob_file.GetBlobFileNumber(), blob_file.GetTotalBlobCount(), blob_file.GetTotalBlobBytes()); compaction_job_info->blob_file_addition_infos.emplace_back( std::move(blob_file_addition_info)); } // Update BlobFilesGarbageInfo. for (const auto& blob_file : c->edit()->GetBlobFileGarbages()) { BlobFileGarbageInfo blob_file_garbage_info( BlobFileName(c->immutable_options()->cf_paths.front().path, blob_file.GetBlobFileNumber()) /*blob_file_path*/, blob_file.GetBlobFileNumber(), blob_file.GetGarbageBlobCount(), blob_file.GetGarbageBlobBytes()); compaction_job_info->blob_file_garbage_infos.emplace_back( std::move(blob_file_garbage_info)); } } // SuperVersionContext gets created and destructed outside of the lock -- // we use this conveniently to: // * malloc one SuperVersion() outside of the lock -- new_superversion // * delete SuperVersion()s outside of the lock -- superversions_to_free // // However, if InstallSuperVersionAndScheduleWork() gets called twice with the // same sv_context, we can't reuse the SuperVersion() that got // malloced because // first call already used it. In that rare case, we take a hit and create a // new SuperVersion() inside of the mutex. We do similar thing // for superversion_to_free void DBImpl::InstallSuperVersionAndScheduleWork( ColumnFamilyData* cfd, SuperVersionContext* sv_context, const MutableCFOptions& mutable_cf_options) { mutex_.AssertHeld(); // Update max_total_in_memory_state_ size_t old_memtable_size = 0; auto* old_sv = cfd->GetSuperVersion(); if (old_sv) { old_memtable_size = old_sv->mutable_cf_options.write_buffer_size * old_sv->mutable_cf_options.max_write_buffer_number; } // this branch is unlikely to step in if (UNLIKELY(sv_context->new_superversion == nullptr)) { sv_context->NewSuperVersion(); } cfd->InstallSuperVersion(sv_context, mutable_cf_options); // There may be a small data race here. The snapshot tricking bottommost // compaction may already be released here. But assuming there will always be // newer snapshot created and released frequently, the compaction will be // triggered soon anyway. bottommost_files_mark_threshold_ = kMaxSequenceNumber; for (auto* my_cfd : *versions_->GetColumnFamilySet()) { if (!my_cfd->ioptions()->allow_ingest_behind) { bottommost_files_mark_threshold_ = std::min( bottommost_files_mark_threshold_, my_cfd->current()->storage_info()->bottommost_files_mark_threshold()); } } // Whenever we install new SuperVersion, we might need to issue new flushes or // compactions. SchedulePendingCompaction(cfd); MaybeScheduleFlushOrCompaction(); // Update max_total_in_memory_state_ max_total_in_memory_state_ = max_total_in_memory_state_ - old_memtable_size + mutable_cf_options.write_buffer_size * mutable_cf_options.max_write_buffer_number; } // ShouldPurge is called by FindObsoleteFiles when doing a full scan, // and db mutex (mutex_) should already be held. // Actually, the current implementation of FindObsoleteFiles with // full_scan=true can issue I/O requests to obtain list of files in // directories, e.g. env_->getChildren while holding db mutex. bool DBImpl::ShouldPurge(uint64_t file_number) const { return files_grabbed_for_purge_.find(file_number) == files_grabbed_for_purge_.end() && purge_files_.find(file_number) == purge_files_.end(); } // MarkAsGrabbedForPurge is called by FindObsoleteFiles, and db mutex // (mutex_) should already be held. void DBImpl::MarkAsGrabbedForPurge(uint64_t file_number) { files_grabbed_for_purge_.insert(file_number); } void DBImpl::SetSnapshotChecker(SnapshotChecker* snapshot_checker) { InstrumentedMutexLock l(&mutex_); // snapshot_checker_ should only set once. If we need to set it multiple // times, we need to make sure the old one is not deleted while it is still // using by a compaction job. assert(!snapshot_checker_); snapshot_checker_.reset(snapshot_checker); } void DBImpl::GetSnapshotContext( JobContext* job_context, std::vector* snapshot_seqs, SequenceNumber* earliest_write_conflict_snapshot, SnapshotChecker** snapshot_checker_ptr) { mutex_.AssertHeld(); assert(job_context != nullptr); assert(snapshot_seqs != nullptr); assert(earliest_write_conflict_snapshot != nullptr); assert(snapshot_checker_ptr != nullptr); *snapshot_checker_ptr = snapshot_checker_.get(); if (use_custom_gc_ && *snapshot_checker_ptr == nullptr) { *snapshot_checker_ptr = DisableGCSnapshotChecker::Instance(); } if (*snapshot_checker_ptr != nullptr) { // If snapshot_checker is used, that means the flush/compaction may // contain values not visible to snapshot taken after // flush/compaction job starts. Take a snapshot and it will appear // in snapshot_seqs and force compaction iterator to consider such // snapshots. const Snapshot* job_snapshot = GetSnapshotImpl(false /*write_conflict_boundary*/, false /*lock*/); job_context->job_snapshot.reset(new ManagedSnapshot(this, job_snapshot)); } *snapshot_seqs = snapshots_.GetAll(earliest_write_conflict_snapshot); } Status DBImpl::WaitForCompact(bool wait_unscheduled) { // Wait until the compaction completes InstrumentedMutexLock l(&mutex_); while ((bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ || bg_flush_scheduled_ || (wait_unscheduled && unscheduled_compactions_)) && (error_handler_.GetBGError().ok())) { bg_cv_.Wait(); } return error_handler_.GetBGError(); } bool DBImpl::InitiateMemoryManagerFlushRequest(size_t min_size_to_flush) { if (shutdown_initiated_) { return false; } FlushOptions flush_options; flush_options.allow_write_stall = true; flush_options.wait = false; if (immutable_db_options_.atomic_flush) { return InitiateMemoryManagerFlushRequestAtomicFlush(min_size_to_flush, flush_options); } else { return InitiateMemoryManagerFlushRequestNonAtomicFlush(min_size_to_flush, flush_options); } } bool DBImpl::InitiateMemoryManagerFlushRequestAtomicFlush( size_t min_size_to_flush, const FlushOptions& flush_options) { assert(immutable_db_options_.atomic_flush); autovector cfds; { InstrumentedMutexLock lock(&mutex_); SelectColumnFamiliesForAtomicFlush(&cfds); if (cfds.empty()) { return false; } // min_size_to_flush may be 0. // Since proactive flushes are active only once recovery is complete => // SelectColumnFamiliesForAtomicFlush() will keep cf-s in cfds collection // only if they have a non-empty mutable memtable or any immutable memtable // => skip the checks and just flush the selected cf-s. if (min_size_to_flush > 0) { size_t total_size_to_flush = 0U; for (const auto& cfd : cfds) { // Once at least one CF has immutable memtables, we will flush if (cfd->imm()->NumNotFlushed() > 0) { // Guarantee a atomic flush will occur total_size_to_flush = min_size_to_flush; break; } else if (cfd->mem()->IsEmpty() == false) { total_size_to_flush += cfd->mem()->ApproximateMemoryUsage(); } } if (total_size_to_flush < min_size_to_flush) { return false; } } } ROCKS_LOG_INFO(immutable_db_options_.info_log, "write buffer manager initiated Atomic flush started current " "usage %lu out of %lu", cfds.front()->write_buffer_mgr()->memory_usage(), cfds.front()->write_buffer_mgr()->buffer_size()); TEST_SYNC_POINT( "DBImpl::InitiateMemoryManagerFlushRequestAtomicFlush::BeforeFlush"); auto s = AtomicFlushMemTables( flush_options, FlushReason::kWriteBufferManagerInitiated, cfds); ROCKS_LOG_INFO( immutable_db_options_.info_log, "write buffer manager initiated Atomic flush finished, status: %s", s.ToString().c_str()); return s.ok(); } bool DBImpl::InitiateMemoryManagerFlushRequestNonAtomicFlush( size_t min_size_to_flush, const FlushOptions& flush_options) { assert(immutable_db_options_.atomic_flush == false); // Pick the "oldest" CF that meets one of the following: // 1. Has at least one IMMUTABLE memtable (=> already has a memtable that // should be flushed); Or // 2. Has a MUTABLE memtable > min size to flush // // However, care must be taken to avoid starving a CF which has data to flush // (=> and associated WAL) but, to which there is not much writing. So, in // case we find such a CF that is lagging enough in the number of flushes it // has undergone, relative to the cf picked originally, we will pick it // instead, regardless of its mutable memtable size. // The CF picked based on min min_size_to_flush ColumnFamilyData* orig_cfd_to_flush = nullptr; // The cf to actually flush (possibly == orig_cfd_to_flush) ColumnFamilyData* cfd_to_flush = nullptr; SequenceNumber seq_num_for_cf_picked = kMaxSequenceNumber; { InstrumentedMutexLock lock(&mutex_); // First pick the oldest CF with data to flush that meets // the min_size_to_flush condition for (auto* cfd : *versions_->GetColumnFamilySet()) { if (cfd->IsDropped()) { continue; } if ((cfd->imm()->NumNotFlushed() != 0) || ((cfd->mem()->IsEmpty() == false) && (cfd->mem()->ApproximateMemoryUsage() >= min_size_to_flush))) { uint64_t seq = cfd->mem()->GetCreationSeq(); if (cfd_to_flush == nullptr || seq < seq_num_for_cf_picked) { cfd_to_flush = cfd; seq_num_for_cf_picked = seq; } } } if (cfd_to_flush == nullptr) { return false; } orig_cfd_to_flush = cfd_to_flush; // A CF was picked. Now see if it should be replaced with a lagging CF for (auto* cfd : *versions_->GetColumnFamilySet()) { if (cfd == orig_cfd_to_flush) { continue; } if ((cfd->imm()->NumNotFlushed() != 0) || (cfd->mem()->IsEmpty() == false)) { // The first lagging CF is picked. There may be another lagging CF that // is older, however, that will be fixed the next time we evaluate. if (cfd->GetNumQueuedForFlush() + ColumnFamilyData::kLaggingFlushesThreshold < orig_cfd_to_flush->GetNumQueuedForFlush()) { // Fix its counter so it is considered lagging again only when // it is indeed lagging behind cfd->SetNumTimedQueuedForFlush( orig_cfd_to_flush->GetNumQueuedForFlush() - 1); cfd_to_flush = cfd; break; } } } autovector cfds{cfd_to_flush}; MaybeFlushStatsCF(&cfds); } ROCKS_LOG_INFO(immutable_db_options_.info_log, "[%s] write buffer manager initiated flush " "started current " "usage %lu out of %lu, min-size:%lu, seq:%" PRIu64 ", num-flushes:%" PRIu64 ", orig-cf:%s num-flushes:%" PRIu64, cfd_to_flush->GetName().c_str(), cfd_to_flush->write_buffer_mgr()->memory_usage(), cfd_to_flush->write_buffer_mgr()->buffer_size(), min_size_to_flush, seq_num_for_cf_picked, cfd_to_flush->GetNumQueuedForFlush(), orig_cfd_to_flush->GetName().c_str(), orig_cfd_to_flush->GetNumQueuedForFlush()); TEST_SYNC_POINT( "DBImpl::InitiateMemoryManagerFlushRequestNonAtomicFlush::BeforeFlush"); auto s = FlushMemTable(cfd_to_flush, flush_options, FlushReason::kWriteBufferManagerInitiated); ROCKS_LOG_INFO( immutable_db_options_.info_log, "[%s] write buffer manager initialize flush finished, status: %s\n", cfd_to_flush->GetName().c_str(), s.ToString().c_str()); return s.ok(); } } // namespace ROCKSDB_NAMESPACE