rocksdb/db/db_impl_debug.cc
Mikhail Antonov 927f274939 Avoiding write stall caused by manual flushes (#4297)
Summary:
Basically at the moment it seems it's possible to cause write stall by calling flush (either manually vis DB::Flush(), or from Backup Engine directly calling FlushMemTable() while background flush may be already happening.

One of the ways to fix it is that in DBImpl::CompactRange() we already check for possible stall and delay flush if needed before we actually proceed to call FlushMemTable(). We can simply move this delay logic to separate method and call it from FlushMemTable.

This is draft patch, for first look; need to check tests/update SyncPoints and most certainly would need to add allow_write_stall method to FlushOptions().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4297

Differential Revision: D9420705

Pulled By: mikhail-antonov

fbshipit-source-id: f81d206b55e1d7b39e4dc64242fdfbceeea03fcc
2018-08-29 12:12:55 -07:00

242 lines
7.1 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef NDEBUG
#include "db/db_impl.h"
#include "db/error_handler.h"
#include "monitoring/thread_status_updater.h"
namespace rocksdb {
uint64_t DBImpl::TEST_GetLevel0TotalSize() {
InstrumentedMutexLock l(&mutex_);
return default_cf_handle_->cfd()->current()->storage_info()->NumLevelBytes(0);
}
void DBImpl::TEST_SwitchWAL() {
WriteContext write_context;
InstrumentedMutexLock l(&mutex_);
SwitchWAL(&write_context);
}
bool DBImpl::TEST_WALBufferIsEmpty() {
InstrumentedMutexLock wl(&log_write_mutex_);
log::Writer* cur_log_writer = logs_.back().writer;
return cur_log_writer->TEST_BufferIsEmpty();
}
int64_t DBImpl::TEST_MaxNextLevelOverlappingBytes(
ColumnFamilyHandle* column_family) {
ColumnFamilyData* cfd;
if (column_family == nullptr) {
cfd = default_cf_handle_->cfd();
} else {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
cfd = cfh->cfd();
}
InstrumentedMutexLock l(&mutex_);
return cfd->current()->storage_info()->MaxNextLevelOverlappingBytes();
}
void DBImpl::TEST_GetFilesMetaData(
ColumnFamilyHandle* column_family,
std::vector<std::vector<FileMetaData>>* metadata) {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
auto cfd = cfh->cfd();
InstrumentedMutexLock l(&mutex_);
metadata->resize(NumberLevels());
for (int level = 0; level < NumberLevels(); level++) {
const std::vector<FileMetaData*>& files =
cfd->current()->storage_info()->LevelFiles(level);
(*metadata)[level].clear();
for (const auto& f : files) {
(*metadata)[level].push_back(*f);
}
}
}
uint64_t DBImpl::TEST_Current_Manifest_FileNo() {
return versions_->manifest_file_number();
}
uint64_t DBImpl::TEST_Current_Next_FileNo() {
return versions_->current_next_file_number();
}
Status DBImpl::TEST_CompactRange(int level, const Slice* begin,
const Slice* end,
ColumnFamilyHandle* column_family,
bool disallow_trivial_move) {
ColumnFamilyData* cfd;
if (column_family == nullptr) {
cfd = default_cf_handle_->cfd();
} else {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
cfd = cfh->cfd();
}
int output_level =
(cfd->ioptions()->compaction_style == kCompactionStyleUniversal ||
cfd->ioptions()->compaction_style == kCompactionStyleFIFO)
? level
: level + 1;
return RunManualCompaction(cfd, level, output_level, 0, 0, begin, end, true,
disallow_trivial_move);
}
Status DBImpl::TEST_SwitchMemtable(ColumnFamilyData* cfd) {
WriteContext write_context;
InstrumentedMutexLock l(&mutex_);
if (cfd == nullptr) {
cfd = default_cf_handle_->cfd();
}
return SwitchMemtable(cfd, &write_context);
}
Status DBImpl::TEST_FlushMemTable(bool wait, bool allow_write_stall,
ColumnFamilyHandle* cfh) {
FlushOptions fo;
fo.wait = wait;
fo.allow_write_stall = allow_write_stall;
ColumnFamilyData* cfd;
if (cfh == nullptr) {
cfd = default_cf_handle_->cfd();
} else {
auto cfhi = reinterpret_cast<ColumnFamilyHandleImpl*>(cfh);
cfd = cfhi->cfd();
}
return FlushMemTable(cfd, fo, FlushReason::kTest);
}
Status DBImpl::TEST_WaitForFlushMemTable(ColumnFamilyHandle* column_family) {
ColumnFamilyData* cfd;
if (column_family == nullptr) {
cfd = default_cf_handle_->cfd();
} else {
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
cfd = cfh->cfd();
}
return WaitForFlushMemTable(cfd);
}
Status DBImpl::TEST_WaitForCompact(bool wait_unscheduled) {
// Wait until the compaction completes
// TODO: a bug here. This function actually does not necessarily
// wait for compact. It actually waits for scheduled compaction
// OR flush to finish.
InstrumentedMutexLock l(&mutex_);
while ((bg_bottom_compaction_scheduled_ || bg_compaction_scheduled_ ||
bg_flush_scheduled_ ||
(wait_unscheduled && unscheduled_compactions_)) &&
!error_handler_.IsDBStopped()) {
bg_cv_.Wait();
}
return error_handler_.GetBGError();
}
void DBImpl::TEST_LockMutex() {
mutex_.Lock();
}
void DBImpl::TEST_UnlockMutex() {
mutex_.Unlock();
}
void* DBImpl::TEST_BeginWrite() {
auto w = new WriteThread::Writer();
write_thread_.EnterUnbatched(w, &mutex_);
return reinterpret_cast<void*>(w);
}
void DBImpl::TEST_EndWrite(void* w) {
auto writer = reinterpret_cast<WriteThread::Writer*>(w);
write_thread_.ExitUnbatched(writer);
delete writer;
}
size_t DBImpl::TEST_LogsToFreeSize() {
InstrumentedMutexLock l(&mutex_);
return logs_to_free_.size();
}
uint64_t DBImpl::TEST_LogfileNumber() {
InstrumentedMutexLock l(&mutex_);
return logfile_number_;
}
Status DBImpl::TEST_GetAllImmutableCFOptions(
std::unordered_map<std::string, const ImmutableCFOptions*>* iopts_map) {
std::vector<std::string> cf_names;
std::vector<const ImmutableCFOptions*> iopts;
{
InstrumentedMutexLock l(&mutex_);
for (auto cfd : *versions_->GetColumnFamilySet()) {
cf_names.push_back(cfd->GetName());
iopts.push_back(cfd->ioptions());
}
}
iopts_map->clear();
for (size_t i = 0; i < cf_names.size(); ++i) {
iopts_map->insert({cf_names[i], iopts[i]});
}
return Status::OK();
}
uint64_t DBImpl::TEST_FindMinLogContainingOutstandingPrep() {
return logs_with_prep_tracker_.FindMinLogContainingOutstandingPrep();
}
size_t DBImpl::TEST_PreparedSectionCompletedSize() {
return logs_with_prep_tracker_.TEST_PreparedSectionCompletedSize();
}
size_t DBImpl::TEST_LogsWithPrepSize() {
return logs_with_prep_tracker_.TEST_LogsWithPrepSize();
}
uint64_t DBImpl::TEST_FindMinPrepLogReferencedByMemTable() {
autovector<MemTable*> empty_list;
return FindMinPrepLogReferencedByMemTable(versions_.get(), nullptr,
empty_list);
}
Status DBImpl::TEST_GetLatestMutableCFOptions(
ColumnFamilyHandle* column_family, MutableCFOptions* mutable_cf_options) {
InstrumentedMutexLock l(&mutex_);
auto cfh = reinterpret_cast<ColumnFamilyHandleImpl*>(column_family);
*mutable_cf_options = *cfh->cfd()->GetLatestMutableCFOptions();
return Status::OK();
}
int DBImpl::TEST_BGCompactionsAllowed() const {
InstrumentedMutexLock l(&mutex_);
return GetBGJobLimits().max_compactions;
}
int DBImpl::TEST_BGFlushesAllowed() const {
InstrumentedMutexLock l(&mutex_);
return GetBGJobLimits().max_flushes;
}
SequenceNumber DBImpl::TEST_GetLastVisibleSequence() const {
if (last_seq_same_as_publish_seq_) {
return versions_->LastSequence();
} else {
return versions_->LastAllocatedSequence();
}
}
} // namespace rocksdb
#endif // NDEBUG