rocksdb/util/sync_point.cc
Igor Canadi db03739340 options.level_compaction_dynamic_level_bytes to allow RocksDB to pick size bases of levels dynamically.
Summary:
When having fixed max_bytes_for_level_base, the ratio of size of largest level and the second one can range from 0 to the multiplier. This makes LSM tree frequently irregular and unpredictable. It can also cause poor space amplification in some cases.

In this improvement (proposed by Igor Kabiljo), we introduce a parameter option.level_compaction_use_dynamic_max_bytes. When turning it on, RocksDB is free to pick a level base in the range of (options.max_bytes_for_level_base/options.max_bytes_for_level_multiplier, options.max_bytes_for_level_base] so that real level ratios are close to options.max_bytes_for_level_multiplier.

Test Plan: New unit tests and pass tests suites including valgrind.

Reviewers: MarkCallaghan, rven, yhchiang, igor, ikabiljo

Reviewed By: ikabiljo

Subscribers: yoshinorim, ikabiljo, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D31437
2015-03-02 22:40:41 -08:00

91 lines
2.2 KiB
C++

// Copyright (c) 2014, 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.
#include "util/sync_point.h"
#ifndef NDEBUG
namespace rocksdb {
SyncPoint* SyncPoint::GetInstance() {
static SyncPoint sync_point;
return &sync_point;
}
void SyncPoint::LoadDependency(const std::vector<Dependency>& dependencies) {
std::unique_lock<std::mutex> lock(mutex_);
successors_.clear();
predecessors_.clear();
cleared_points_.clear();
for (const auto& dependency : dependencies) {
successors_[dependency.predecessor].push_back(dependency.successor);
predecessors_[dependency.successor].push_back(dependency.predecessor);
}
cv_.notify_all();
}
bool SyncPoint::PredecessorsAllCleared(const std::string& point) {
for (const auto& pred : predecessors_[point]) {
if (cleared_points_.count(pred) == 0) {
return false;
}
}
return true;
}
void SyncPoint::SetCallBack(const std::string point,
std::function<void()> callback) {
std::unique_lock<std::mutex> lock(mutex_);
callbacks_[point] = callback;
}
void SyncPoint::ClearAllCallBacks() {
std::unique_lock<std::mutex> lock(mutex_);
while (num_callbacks_running_ > 0) {
cv_.wait(lock);
}
callbacks_.clear();
}
void SyncPoint::EnableProcessing() {
std::unique_lock<std::mutex> lock(mutex_);
enabled_ = true;
}
void SyncPoint::DisableProcessing() {
std::unique_lock<std::mutex> lock(mutex_);
enabled_ = false;
}
void SyncPoint::ClearTrace() {
std::unique_lock<std::mutex> lock(mutex_);
cleared_points_.clear();
}
void SyncPoint::Process(const std::string& point) {
std::unique_lock<std::mutex> lock(mutex_);
if (!enabled_) return;
auto callback_pair = callbacks_.find(point);
if (callback_pair != callbacks_.end()) {
num_callbacks_running_++;
mutex_.unlock();
callback_pair->second();
mutex_.lock();
num_callbacks_running_--;
cv_.notify_all();
}
while (!PredecessorsAllCleared(point)) {
cv_.wait(lock);
}
cleared_points_.insert(point);
cv_.notify_all();
}
} // namespace rocksdb
#endif // NDEBUG