rocksdb/db/flush_job.cc
Yueh-Hsuan Chiang 181191a1e4 Add a counter for collecting the wait time on db mutex.
Summary:
Add a counter for collecting the wait time on db mutex.
Also add MutexWrapper and CondVarWrapper for measuring wait time.

Test Plan:
./db_test
export ROCKSDB_TESTS=MutexWaitStats
./db_test

verify stats output using db_bench
make clean
make release
./db_bench --statistics=1 --benchmarks=fillseq,readwhilewriting --num=10000 --threads=10

Sample output:
    rocksdb.db.mutex.wait.micros COUNT : 7546866

Reviewers: MarkCallaghan, rven, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32787
2015-02-04 21:39:45 -08:00

222 lines
8.1 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "db/flush_job.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <algorithm>
#include <vector>
#include "db/builder.h"
#include "db/db_iter.h"
#include "db/dbformat.h"
#include "db/filename.h"
#include "db/log_reader.h"
#include "db/log_writer.h"
#include "db/memtable.h"
#include "db/memtable_list.h"
#include "db/merge_context.h"
#include "db/version_set.h"
#include "port/port.h"
#include "port/likely.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "rocksdb/statistics.h"
#include "rocksdb/status.h"
#include "rocksdb/table.h"
#include "table/block.h"
#include "table/block_based_table_factory.h"
#include "table/merger.h"
#include "table/table_builder.h"
#include "table/two_level_iterator.h"
#include "util/coding.h"
#include "util/file_util.h"
#include "util/logging.h"
#include "util/log_buffer.h"
#include "util/mutexlock.h"
#include "util/perf_context_imp.h"
#include "util/iostats_context_imp.h"
#include "util/stop_watch.h"
#include "util/sync_point.h"
namespace rocksdb {
FlushJob::FlushJob(const std::string& dbname, ColumnFamilyData* cfd,
const DBOptions& db_options,
const MutableCFOptions& mutable_cf_options,
const EnvOptions& env_options, VersionSet* versions,
InstrumentedMutex* db_mutex,
std::atomic<bool>* shutting_down,
SequenceNumber newest_snapshot, JobContext* job_context,
LogBuffer* log_buffer, Directory* db_directory,
Directory* output_file_directory,
CompressionType output_compression, Statistics* stats)
: dbname_(dbname),
cfd_(cfd),
db_options_(db_options),
mutable_cf_options_(mutable_cf_options),
env_options_(env_options),
versions_(versions),
db_mutex_(db_mutex),
shutting_down_(shutting_down),
newest_snapshot_(newest_snapshot),
job_context_(job_context),
log_buffer_(log_buffer),
db_directory_(db_directory),
output_file_directory_(output_file_directory),
output_compression_(output_compression),
stats_(stats) {}
Status FlushJob::Run(uint64_t* file_number) {
// Save the contents of the earliest memtable as a new Table
uint64_t fn;
autovector<MemTable*> mems;
cfd_->imm()->PickMemtablesToFlush(&mems);
if (mems.empty()) {
LogToBuffer(log_buffer_, "[%s] Nothing in memtable to flush",
cfd_->GetName().c_str());
return Status::OK();
}
// entries mems are (implicitly) sorted in ascending order by their created
// time. We will use the first memtable's `edit` to keep the meta info for
// this flush.
MemTable* m = mems[0];
VersionEdit* edit = m->GetEdits();
edit->SetPrevLogNumber(0);
// SetLogNumber(log_num) indicates logs with number smaller than log_num
// will no longer be picked up for recovery.
edit->SetLogNumber(mems.back()->GetNextLogNumber());
edit->SetColumnFamily(cfd_->GetID());
// This will release and re-acquire the mutex.
Status s = WriteLevel0Table(mems, edit, &fn);
if (s.ok() &&
(shutting_down_->load(std::memory_order_acquire) || cfd_->IsDropped())) {
s = Status::ShutdownInProgress(
"Database shutdown or Column family drop during flush");
}
if (!s.ok()) {
cfd_->imm()->RollbackMemtableFlush(mems, fn);
} else {
// Replace immutable memtable with the generated Table
s = cfd_->imm()->InstallMemtableFlushResults(
cfd_, mutable_cf_options_, mems, versions_, db_mutex_, fn,
&job_context_->memtables_to_free, db_directory_, log_buffer_);
}
if (s.ok() && file_number != nullptr) {
*file_number = fn;
}
return s;
}
Status FlushJob::WriteLevel0Table(const autovector<MemTable*>& mems,
VersionEdit* edit, uint64_t* filenumber) {
db_mutex_->AssertHeld();
const uint64_t start_micros = db_options_.env->NowMicros();
FileMetaData meta;
// path 0 for level 0 file.
meta.fd = FileDescriptor(versions_->NewFileNumber(), 0, 0);
*filenumber = meta.fd.GetNumber();
const SequenceNumber earliest_seqno_in_memtable =
mems[0]->GetFirstSequenceNumber();
Version* base = cfd_->current();
base->Ref(); // it is likely that we do not need this reference
Status s;
{
db_mutex_->Unlock();
if (log_buffer_) {
log_buffer_->FlushBufferToLog();
}
std::vector<Iterator*> memtables;
ReadOptions ro;
ro.total_order_seek = true;
Arena arena;
for (MemTable* m : mems) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"[%s] Flushing memtable with next log file: %" PRIu64 "\n",
cfd_->GetName().c_str(), m->GetNextLogNumber());
memtables.push_back(m->NewIterator(ro, &arena));
}
{
ScopedArenaIterator iter(
NewMergingIterator(&cfd_->internal_comparator(), &memtables[0],
static_cast<int>(memtables.size()), &arena));
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"[%s] Level-0 flush table #%" PRIu64 ": started",
cfd_->GetName().c_str(), meta.fd.GetNumber());
s = BuildTable(dbname_, db_options_.env, *cfd_->ioptions(), env_options_,
cfd_->table_cache(), iter.get(), &meta,
cfd_->internal_comparator(), newest_snapshot_,
earliest_seqno_in_memtable, output_compression_,
cfd_->ioptions()->compression_opts, Env::IO_HIGH);
LogFlush(db_options_.info_log);
}
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"[%s] Level-0 flush table #%" PRIu64 ": %" PRIu64 " bytes %s",
cfd_->GetName().c_str(), meta.fd.GetNumber(), meta.fd.GetFileSize(),
s.ToString().c_str());
if (!db_options_.disableDataSync && output_file_directory_ != nullptr) {
output_file_directory_->Fsync();
}
db_mutex_->Lock();
}
base->Unref();
// re-acquire the most current version
base = cfd_->current();
// Note that if file_size is zero, the file has been deleted and
// should not be added to the manifest.
int level = 0;
if (s.ok() && meta.fd.GetFileSize() > 0) {
const Slice min_user_key = meta.smallest.user_key();
const Slice max_user_key = meta.largest.user_key();
// if we have more than 1 background thread, then we cannot
// insert files directly into higher levels because some other
// threads could be concurrently producing compacted files for
// that key range.
if (base != nullptr && db_options_.max_background_compactions <= 1 &&
db_options_.max_background_flushes == 0 &&
cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
level = base->storage_info()->PickLevelForMemTableOutput(
mutable_cf_options_, min_user_key, max_user_key);
// If level does not match path id, reset level back to 0
uint32_t fdpath = LevelCompactionPicker::GetPathId(
*cfd_->ioptions(), mutable_cf_options_, level);
if (fdpath != 0) {
level = 0;
}
}
edit->AddFile(level, meta.fd.GetNumber(), meta.fd.GetPathId(),
meta.fd.GetFileSize(), meta.smallest, meta.largest,
meta.smallest_seqno, meta.largest_seqno);
}
InternalStats::CompactionStats stats(1);
stats.micros = db_options_.env->NowMicros() - start_micros;
stats.bytes_written = meta.fd.GetFileSize();
cfd_->internal_stats()->AddCompactionStats(level, stats);
cfd_->internal_stats()->AddCFStats(InternalStats::BYTES_FLUSHED,
meta.fd.GetFileSize());
RecordTick(stats_, COMPACT_WRITE_BYTES, meta.fd.GetFileSize());
return s;
}
} // namespace rocksdb