andreacavalli/rocksdb
0
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Write Fast-path for single column family

Browse Source 
Summary: We have a perf regression of Write() even with one column family. Make fast path for single column family to avoid the perf regression. See task #4455480

Test Plan: make check

Reviewers: sdong, ljin

Reviewed By: sdong, ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D18963
This commit is contained in:
Igor Canadi 2014-06-06 17:26:23 -07:00
parent e72b02e3c2
commit 99d3eed2fd
2 changed files with 35 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
db/db_impl.cc
View File

@ -1149,6 +1149,8 @@ Status DBImpl::Recover(
SequenceNumber max_sequence(0);
default_cf_handle_ = new ColumnFamilyHandleImpl(
versions_->GetColumnFamilySet()->GetDefault(), this, &mutex_);
single_column_family_mode_ =
versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1;
// Recover from all newer log files than the ones named in the
// descriptor (new log files may have been added by the previous
@ -3477,6 +3479,7 @@ Status DBImpl::CreateColumnFamily(const ColumnFamilyOptions& options,
Status s = versions_->LogAndApply(nullptr, &edit, &mutex_,
db_directory_.get(), false, &options);
if (s.ok()) {
single_column_family_mode_ = false;
auto cfd =
versions_->GetColumnFamilySet()->GetColumnFamily(column_family_name);
assert(cfd != nullptr);
@ -3746,11 +3749,14 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) {
RecordTick(options_.statistics.get(), WRITE_DONE_BY_SELF, 1);
}
assert(!single_column_family_mode_ ||
versions_->GetColumnFamilySet()->NumberOfColumnFamilies() == 1);
uint64_t flush_column_family_if_log_file = 0;
uint64_t max_total_wal_size = (options_.max_total_wal_size == 0)
? 4 * max_total_in_memory_state_
: options_.max_total_wal_size;
if (versions_->GetColumnFamilySet()->NumberOfColumnFamilies() > 1 &&
if (UNLIKELY(!single_column_family_mode_) &&
alive_log_files_.begin()->getting_flushed == false &&
total_log_size_ > max_total_wal_size) {
flush_column_family_if_log_file = alive_log_files_.begin()->number;
@ -3762,28 +3768,36 @@ Status DBImpl::Write(const WriteOptions& options, WriteBatch* my_batch) {
}
Status status;
// refcounting cfd in iteration
bool dead_cfd = false;
autovector<SuperVersion*> superversions_to_free;
autovector<log::Writer*> logs_to_free;
for (auto cfd : *versions_->GetColumnFamilySet()) {
cfd->Ref();
bool force_flush = my_batch == nullptr ||
(flush_column_family_if_log_file != 0 &&
cfd->GetLogNumber() <= flush_column_family_if_log_file);
// May temporarily unlock and wait.
status = MakeRoomForWrite(cfd, force_flush, &superversions_to_free,
&logs_to_free);
if (cfd->Unref()) {
dead_cfd = true;
if (LIKELY(single_column_family_mode_)) {
// fast path
status = MakeRoomForWrite(default_cf_handle_->cfd(), my_batch == nullptr,
&superversions_to_free, &logs_to_free);
} else {
// refcounting cfd in iteration
bool dead_cfd = false;
for (auto cfd : *versions_->GetColumnFamilySet()) {
cfd->Ref();
bool force_flush =
my_batch == nullptr ||
(flush_column_family_if_log_file != 0 &&
cfd->GetLogNumber() <= flush_column_family_if_log_file);
// May temporarily unlock and wait.
status = MakeRoomForWrite(cfd, force_flush, &superversions_to_free,
&logs_to_free);
if (cfd->Unref()) {
dead_cfd = true;
}
if (!status.ok()) {
break;
}
}
if (!status.ok()) {
break;
if (dead_cfd) {
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
}
}
if (dead_cfd) {
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
}
uint64_t last_sequence = versions_->LastSequence();
Writer* last_writer = &w;

3
db/db_impl.h
View File

@ -480,6 +480,9 @@ class DBImpl : public DB {
// only used for dynamically adjusting max_total_wal_size. it is a sum of
// [write_buffer_size * max_write_buffer_number] over all column families
uint64_t max_total_in_memory_state_;
// If true, we have only one (default) column family. We use this to optimize
// some code-paths
bool single_column_family_mode_;
std::string host_name_;