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move LevelCompactionPicker to a separate file (#5369) 

Summary:
In order to improve code readability, this PR moves LevelCompactionBuilder and LevelCompactionPicker to compaction_picker_level.h and .cc
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5369

Differential Revision: D15540172

Pulled By: miasantreble

fbshipit-source-id: c1a578b93f127cd63661b53f32b356e6edd349af
This commit is contained in:
Zhongyi Xie 2019-05-30 21:30:41 -07:00 committed by Facebook Github Bot
parent ff9d286877
commit ab8f6c01a6
9 changed files with 596 additions and 552 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
CMakeLists.txt
View File

@ -485,6 +485,7 @@ set(SOURCES
db/compaction_job.cc
db/compaction_picker.cc
db/compaction_picker_fifo.cc
db/compaction_picker_level.cc
db/compaction_picker_universal.cc
db/convenience.cc
db/db_filesnapshot.cc
@ -945,7 +946,7 @@ if(WITH_TESTS)
table/block_based/block_test.cc
table/block_based/data_block_hash_index_test.cc
table/block_based/full_filter_block_test.cc
table/block_based/partitioned_filter_block_test.cc
table/block_based/partitioned_filter_block_test.cc
table/cleanable_test.cc
table/cuckoo/cuckoo_table_builder_test.cc
table/cuckoo/cuckoo_table_reader_test.cc

1
TARGETS
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@ -88,6 +88,7 @@ cpp_library(
"db/compaction_job.cc",
"db/compaction_picker.cc",
"db/compaction_picker_fifo.cc",
"db/compaction_picker_level.cc",
"db/compaction_picker_universal.cc",
"db/convenience.cc",
"db/db_filesnapshot.cc",

1
db/column_family.cc
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@ -21,6 +21,7 @@
#include "db/compaction_picker.h"
#include "db/compaction_picker_fifo.h"
#include "db/compaction_picker_level.h"
#include "db/compaction_picker_universal.h"
#include "db/db_impl.h"
#include "db/internal_stats.h"

534
db/compaction_picker.cc
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@ -1111,538 +1111,4 @@ bool CompactionPicker::GetOverlappingL0Files(
return true;
}
bool LevelCompactionPicker::NeedsCompaction(
const VersionStorageInfo* vstorage) const {
if (!vstorage->ExpiredTtlFiles().empty()) {
return true;
}
if (!vstorage->FilesMarkedForPeriodicCompaction().empty()) {
return true;
}
if (!vstorage->BottommostFilesMarkedForCompaction().empty()) {
return true;
}
if (!vstorage->FilesMarkedForCompaction().empty()) {
return true;
}
for (int i = 0; i <= vstorage->MaxInputLevel(); i++) {
if (vstorage->CompactionScore(i) >= 1) {
return true;
}
}
return false;
}
namespace {
// A class to build a leveled compaction step-by-step.
class LevelCompactionBuilder {
public:
LevelCompactionBuilder(const std::string& cf_name,
VersionStorageInfo* vstorage,
CompactionPicker* compaction_picker,
LogBuffer* log_buffer,
const MutableCFOptions& mutable_cf_options,
const ImmutableCFOptions& ioptions)
: cf_name_(cf_name),
vstorage_(vstorage),
compaction_picker_(compaction_picker),
log_buffer_(log_buffer),
mutable_cf_options_(mutable_cf_options),
ioptions_(ioptions) {}
// Pick and return a compaction.
Compaction* PickCompaction();
// Pick the initial files to compact to the next level. (or together
// in Intra-L0 compactions)
void SetupInitialFiles();
// If the initial files are from L0 level, pick other L0
// files if needed.
bool SetupOtherL0FilesIfNeeded();
// Based on initial files, setup other files need to be compacted
// in this compaction, accordingly.
bool SetupOtherInputsIfNeeded();
Compaction* GetCompaction();
// For the specfied level, pick a file that we want to compact.
// Returns false if there is no file to compact.
// If it returns true, inputs->files.size() will be exactly one.
// If level is 0 and there is already a compaction on that level, this
// function will return false.
bool PickFileToCompact();
// For L0->L0, picks the longest span of files that aren't currently
// undergoing compaction for which work-per-deleted-file decreases. The span
// always starts from the newest L0 file.
//
// Intra-L0 compaction is independent of all other files, so it can be
// performed even when L0->base_level compactions are blocked.
//
// Returns true if `inputs` is populated with a span of files to be compacted;
// otherwise, returns false.
bool PickIntraL0Compaction();
void PickExpiredTtlFiles();
void PickFilesMarkedForPeriodicCompaction();
const std::string& cf_name_;
VersionStorageInfo* vstorage_;
CompactionPicker* compaction_picker_;
LogBuffer* log_buffer_;
int start_level_ = -1;
int output_level_ = -1;
int parent_index_ = -1;
int base_index_ = -1;
double start_level_score_ = 0;
bool is_manual_ = false;
CompactionInputFiles start_level_inputs_;
std::vector<CompactionInputFiles> compaction_inputs_;
CompactionInputFiles output_level_inputs_;
std::vector<FileMetaData*> grandparents_;
CompactionReason compaction_reason_ = CompactionReason::kUnknown;
const MutableCFOptions& mutable_cf_options_;
const ImmutableCFOptions& ioptions_;
// Pick a path ID to place a newly generated file, with its level
static uint32_t GetPathId(const ImmutableCFOptions& ioptions,
const MutableCFOptions& mutable_cf_options,
int level);
static const int kMinFilesForIntraL0Compaction = 4;
};
void LevelCompactionBuilder::PickExpiredTtlFiles() {
if (vstorage_->ExpiredTtlFiles().empty()) {
return;
}
auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
// If it's being compacted it has nothing to do here.
// If this assert() fails that means that some function marked some
// files as being_compacted, but didn't call ComputeCompactionScore()
assert(!level_file.second->being_compacted);
start_level_ = level_file.first;
output_level_ =
(start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
if ((start_level_ == vstorage_->num_non_empty_levels() - 1) ||
(start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty())) {
return false;
}
start_level_inputs_.files = {level_file.second};
start_level_inputs_.level = start_level_;
return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_);
};
for (auto& level_file : vstorage_->ExpiredTtlFiles()) {
if (continuation(level_file)) {
// found the compaction!
return;
}
}
start_level_inputs_.files.clear();
}
void LevelCompactionBuilder::PickFilesMarkedForPeriodicCompaction() {
if (vstorage_->FilesMarkedForPeriodicCompaction().empty()) {
return;
}
auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
// If it's being compacted it has nothing to do here.
// If this assert() fails that means that some function marked some
// files as being_compacted, but didn't call ComputeCompactionScore()
assert(!level_file.second->being_compacted);
output_level_ = start_level_ = level_file.first;
if (start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty()) {
return false;
}
start_level_inputs_.files = {level_file.second};
start_level_inputs_.level = start_level_;
return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_);
};
for (auto& level_file : vstorage_->FilesMarkedForPeriodicCompaction()) {
if (continuation(level_file)) {
// found the compaction!
return;
}
}
start_level_inputs_.files.clear();
}
void LevelCompactionBuilder::SetupInitialFiles() {
// Find the compactions by size on all levels.
bool skipped_l0_to_base = false;
for (int i = 0; i < compaction_picker_->NumberLevels() - 1; i++) {
start_level_score_ = vstorage_->CompactionScore(i);
start_level_ = vstorage_->CompactionScoreLevel(i);
assert(i == 0 || start_level_score_ <= vstorage_->CompactionScore(i - 1));
if (start_level_score_ >= 1) {
if (skipped_l0_to_base && start_level_ == vstorage_->base_level()) {
// If L0->base_level compaction is pending, don't schedule further
// compaction from base level. Otherwise L0->base_level compaction
// may starve.
continue;
}
output_level_ =
(start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
if (PickFileToCompact()) {
// found the compaction!
if (start_level_ == 0) {
// L0 score = `num L0 files` / `level0_file_num_compaction_trigger`
compaction_reason_ = CompactionReason::kLevelL0FilesNum;
} else {
// L1+ score = `Level files size` / `MaxBytesForLevel`
compaction_reason_ = CompactionReason::kLevelMaxLevelSize;
}
break;
} else {
// didn't find the compaction, clear the inputs
start_level_inputs_.clear();
if (start_level_ == 0) {
skipped_l0_to_base = true;
// L0->base_level may be blocked due to ongoing L0->base_level
// compactions. It may also be blocked by an ongoing compaction from
// base_level downwards.
//
// In these cases, to reduce L0 file count and thus reduce likelihood
// of write stalls, we can attempt compacting a span of files within
// L0.
if (PickIntraL0Compaction()) {
output_level_ = 0;
compaction_reason_ = CompactionReason::kLevelL0FilesNum;
break;
}
}
}
}
}
// if we didn't find a compaction, check if there are any files marked for
// compaction
if (start_level_inputs_.empty()) {
parent_index_ = base_index_ = -1;
compaction_picker_->PickFilesMarkedForCompaction(
cf_name_, vstorage_, &start_level_, &output_level_, &start_level_inputs_);
if (!start_level_inputs_.empty()) {
is_manual_ = true;
compaction_reason_ = CompactionReason::kFilesMarkedForCompaction;
return;
}
}
// Bottommost Files Compaction on deleting tombstones
if (start_level_inputs_.empty()) {
size_t i;
for (i = 0; i < vstorage_->BottommostFilesMarkedForCompaction().size();
++i) {
auto& level_and_file = vstorage_->BottommostFilesMarkedForCompaction()[i];
assert(!level_and_file.second->being_compacted);
start_level_inputs_.level = output_level_ = start_level_ =
level_and_file.first;
start_level_inputs_.files = {level_and_file.second};
if (compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_)) {
break;
}
}
if (i == vstorage_->BottommostFilesMarkedForCompaction().size()) {
start_level_inputs_.clear();
} else {
assert(!start_level_inputs_.empty());
compaction_reason_ = CompactionReason::kBottommostFiles;
return;
}
}
// TTL Compaction
if (start_level_inputs_.empty()) {
PickExpiredTtlFiles();
if (!start_level_inputs_.empty()) {
compaction_reason_ = CompactionReason::kTtl;
return;
}
}
// Periodic Compaction
if (start_level_inputs_.empty()) {
PickFilesMarkedForPeriodicCompaction();
if (!start_level_inputs_.empty()) {
compaction_reason_ = CompactionReason::kPeriodicCompaction;
return;
}
}
}
bool LevelCompactionBuilder::SetupOtherL0FilesIfNeeded() {
if (start_level_ == 0 && output_level_ != 0) {
return compaction_picker_->GetOverlappingL0Files(
vstorage_, &start_level_inputs_, output_level_, &parent_index_);
}
return true;
}
bool LevelCompactionBuilder::SetupOtherInputsIfNeeded() {
// Setup input files from output level. For output to L0, we only compact
// spans of files that do not interact with any pending compactions, so don't
// need to consider other levels.
if (output_level_ != 0) {
output_level_inputs_.level = output_level_;
if (!compaction_picker_->SetupOtherInputs(
cf_name_, mutable_cf_options_, vstorage_, &start_level_inputs_,
&output_level_inputs_, &parent_index_, base_index_)) {
return false;
}
compaction_inputs_.push_back(start_level_inputs_);
if (!output_level_inputs_.empty()) {
compaction_inputs_.push_back(output_level_inputs_);
}
// In some edge cases we could pick a compaction that will be compacting
// a key range that overlap with another running compaction, and both
// of them have the same output level. This could happen if
// (1) we are running a non-exclusive manual compaction
// (2) AddFile ingest a new file into the LSM tree
// We need to disallow this from happening.
if (compaction_picker_->FilesRangeOverlapWithCompaction(compaction_inputs_,
output_level_)) {
// This compaction output could potentially conflict with the output
// of a currently running compaction, we cannot run it.
return false;
}
compaction_picker_->GetGrandparents(vstorage_, start_level_inputs_,
output_level_inputs_, &grandparents_);
} else {
compaction_inputs_.push_back(start_level_inputs_);
}
return true;
}
Compaction* LevelCompactionBuilder::PickCompaction() {
// Pick up the first file to start compaction. It may have been extended
// to a clean cut.
SetupInitialFiles();
if (start_level_inputs_.empty()) {
return nullptr;
}
assert(start_level_ >= 0 && output_level_ >= 0);
// If it is a L0 -> base level compaction, we need to set up other L0
// files if needed.
if (!SetupOtherL0FilesIfNeeded()) {
return nullptr;
}
// Pick files in the output level and expand more files in the start level
// if needed.
if (!SetupOtherInputsIfNeeded()) {
return nullptr;
}
// Form a compaction object containing the files we picked.
Compaction* c = GetCompaction();
TEST_SYNC_POINT_CALLBACK("LevelCompactionPicker::PickCompaction:Return", c);
return c;
}
Compaction* LevelCompactionBuilder::GetCompaction() {
auto c = new Compaction(
vstorage_, ioptions_, mutable_cf_options_, std::move(compaction_inputs_),
output_level_,
MaxFileSizeForLevel(mutable_cf_options_, output_level_,
ioptions_.compaction_style, vstorage_->base_level(),
ioptions_.level_compaction_dynamic_level_bytes),
mutable_cf_options_.max_compaction_bytes,
GetPathId(ioptions_, mutable_cf_options_, output_level_),
GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
output_level_, vstorage_->base_level()),
GetCompressionOptions(ioptions_, vstorage_, output_level_),
/* max_subcompactions */ 0, std::move(grandparents_), is_manual_,
start_level_score_, false /* deletion_compaction */, compaction_reason_);
// If it's level 0 compaction, make sure we don't execute any other level 0
// compactions in parallel
compaction_picker_->RegisterCompaction(c);
// 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
vstorage_->ComputeCompactionScore(ioptions_, mutable_cf_options_);
return c;
}
/*
* Find the optimal path to place a file
* Given a level, finds the path where levels up to it will fit in levels
* up to and including this path
*/
uint32_t LevelCompactionBuilder::GetPathId(
const ImmutableCFOptions& ioptions,
const MutableCFOptions& mutable_cf_options, int level) {
uint32_t p = 0;
assert(!ioptions.cf_paths.empty());
// size remaining in the most recent path
uint64_t current_path_size = ioptions.cf_paths[0].target_size;
uint64_t level_size;
int cur_level = 0;
// max_bytes_for_level_base denotes L1 size.
// We estimate L0 size to be the same as L1.
level_size = mutable_cf_options.max_bytes_for_level_base;
// Last path is the fallback
while (p < ioptions.cf_paths.size() - 1) {
if (level_size <= current_path_size) {
if (cur_level == level) {
// Does desired level fit in this path?
return p;
} else {
current_path_size -= level_size;
if (cur_level > 0) {
if (ioptions.level_compaction_dynamic_level_bytes) {
// Currently, level_compaction_dynamic_level_bytes is ignored when
// multiple db paths are specified. https://github.com/facebook/
// rocksdb/blob/master/db/column_family.cc.
// Still, adding this check to avoid accidentally using
// max_bytes_for_level_multiplier_additional
level_size = static_cast<uint64_t>(
level_size * mutable_cf_options.max_bytes_for_level_multiplier);
} else {
level_size = static_cast<uint64_t>(
level_size * mutable_cf_options.max_bytes_for_level_multiplier *
mutable_cf_options.MaxBytesMultiplerAdditional(cur_level));
}
}
cur_level++;
continue;
}
}
p++;
current_path_size = ioptions.cf_paths[p].target_size;
}
return p;
}
bool LevelCompactionBuilder::PickFileToCompact() {
// level 0 files are overlapping. So we cannot pick more
// than one concurrent compactions at this level. This
// could be made better by looking at key-ranges that are
// being compacted at level 0.
if (start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty()) {
TEST_SYNC_POINT("LevelCompactionPicker::PickCompactionBySize:0");
return false;
}
start_level_inputs_.clear();
assert(start_level_ >= 0);
// Pick the largest file in this level that is not already
// being compacted
const std::vector<int>& file_size =
vstorage_->FilesByCompactionPri(start_level_);
const std::vector<FileMetaData*>& level_files =
vstorage_->LevelFiles(start_level_);
unsigned int cmp_idx;
for (cmp_idx = vstorage_->NextCompactionIndex(start_level_);
cmp_idx < file_size.size(); cmp_idx++) {
int index = file_size[cmp_idx];
auto* f = level_files[index];
// do not pick a file to compact if it is being compacted
// from n-1 level.
if (f->being_compacted) {
continue;
}
start_level_inputs_.files.push_back(f);
start_level_inputs_.level = start_level_;
if (!compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_) ||
compaction_picker_->FilesRangeOverlapWithCompaction(
{start_level_inputs_}, output_level_)) {
// A locked (pending compaction) input-level file was pulled in due to
// user-key overlap.
start_level_inputs_.clear();
continue;
}
// Now that input level is fully expanded, we check whether any output files
// are locked due to pending compaction.
//
// Note we rely on ExpandInputsToCleanCut() to tell us whether any output-
// level files are locked, not just the extra ones pulled in for user-key
// overlap.
InternalKey smallest, largest;
compaction_picker_->GetRange(start_level_inputs_, &smallest, &largest);
CompactionInputFiles output_level_inputs;
output_level_inputs.level = output_level_;
vstorage_->GetOverlappingInputs(output_level_, &smallest, &largest,
&output_level_inputs.files);
if (!output_level_inputs.empty() &&
!compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&output_level_inputs)) {
start_level_inputs_.clear();
continue;
}
base_index_ = index;
break;
}
// store where to start the iteration in the next call to PickCompaction
vstorage_->SetNextCompactionIndex(start_level_, cmp_idx);
return start_level_inputs_.size() > 0;
}
bool LevelCompactionBuilder::PickIntraL0Compaction() {
start_level_inputs_.clear();
const std::vector<FileMetaData*>& level_files =
vstorage_->LevelFiles(0 /* level */);
if (level_files.size() <
static_cast<size_t>(
mutable_cf_options_.level0_file_num_compaction_trigger + 2) ||
level_files[0]->being_compacted) {
// If L0 isn't accumulating much files beyond the regular trigger, don't
// resort to L0->L0 compaction yet.
return false;
}
return FindIntraL0Compaction(level_files, kMinFilesForIntraL0Compaction,
port::kMaxUint64,
mutable_cf_options_.max_compaction_bytes,
&start_level_inputs_);
}
} // namespace
Compaction* LevelCompactionPicker::PickCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
VersionStorageInfo* vstorage, LogBuffer* log_buffer) {
LevelCompactionBuilder builder(cf_name, vstorage, this, log_buffer,
mutable_cf_options, ioptions_);
return builder.PickCompaction();
}
} // namespace rocksdb

17
db/compaction_picker.h
View File

@ -236,23 +236,6 @@ class CompactionPicker {
const InternalKeyComparator* const icmp_;
};
// Picking compactions for leveled compaction. See wiki page
// https://github.com/facebook/rocksdb/wiki/Leveled-Compaction
// for description of Leveled compaction.
class LevelCompactionPicker : public CompactionPicker {
public:
LevelCompactionPicker(const ImmutableCFOptions& ioptions,
const InternalKeyComparator* icmp)
: CompactionPicker(ioptions, icmp) {}
virtual Compaction* PickCompaction(const std::string& cf_name,
const MutableCFOptions& mutable_cf_options,
VersionStorageInfo* vstorage,
LogBuffer* log_buffer) override;
virtual bool NeedsCompaction(
const VersionStorageInfo* vstorage) const override;
};
#ifndef ROCKSDB_LITE
// A dummy compaction that never triggers any automatic
// compaction.

558
db/compaction_picker_level.cc Normal file
View File

@ -0,0 +1,558 @@
// 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 "db/compaction_picker_level.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <string>
#include <utility>
#include <vector>
#include "test_util/sync_point.h"
#include "util/log_buffer.h"
namespace rocksdb {
bool LevelCompactionPicker::NeedsCompaction(
const VersionStorageInfo* vstorage) const {
if (!vstorage->ExpiredTtlFiles().empty()) {
return true;
}
if (!vstorage->FilesMarkedForPeriodicCompaction().empty()) {
return true;
}
if (!vstorage->BottommostFilesMarkedForCompaction().empty()) {
return true;
}
if (!vstorage->FilesMarkedForCompaction().empty()) {
return true;
}
for (int i = 0; i <= vstorage->MaxInputLevel(); i++) {
if (vstorage->CompactionScore(i) >= 1) {
return true;
}
}
return false;
}
namespace {
// A class to build a leveled compaction step-by-step.
class LevelCompactionBuilder {
public:
LevelCompactionBuilder(const std::string& cf_name,
VersionStorageInfo* vstorage,
CompactionPicker* compaction_picker,
LogBuffer* log_buffer,
const MutableCFOptions& mutable_cf_options,
const ImmutableCFOptions& ioptions)
: cf_name_(cf_name),
vstorage_(vstorage),
compaction_picker_(compaction_picker),
log_buffer_(log_buffer),
mutable_cf_options_(mutable_cf_options),
ioptions_(ioptions) {}
// Pick and return a compaction.
Compaction* PickCompaction();
// Pick the initial files to compact to the next level. (or together
// in Intra-L0 compactions)
void SetupInitialFiles();
// If the initial files are from L0 level, pick other L0
// files if needed.
bool SetupOtherL0FilesIfNeeded();
// Based on initial files, setup other files need to be compacted
// in this compaction, accordingly.
bool SetupOtherInputsIfNeeded();
Compaction* GetCompaction();
// For the specfied level, pick a file that we want to compact.
// Returns false if there is no file to compact.
// If it returns true, inputs->files.size() will be exactly one.
// If level is 0 and there is already a compaction on that level, this
// function will return false.
bool PickFileToCompact();
// For L0->L0, picks the longest span of files that aren't currently
// undergoing compaction for which work-per-deleted-file decreases. The span
// always starts from the newest L0 file.
//
// Intra-L0 compaction is independent of all other files, so it can be
// performed even when L0->base_level compactions are blocked.
//
// Returns true if `inputs` is populated with a span of files to be compacted;
// otherwise, returns false.
bool PickIntraL0Compaction();
void PickExpiredTtlFiles();
void PickFilesMarkedForPeriodicCompaction();
const std::string& cf_name_;
VersionStorageInfo* vstorage_;
CompactionPicker* compaction_picker_;
LogBuffer* log_buffer_;
int start_level_ = -1;
int output_level_ = -1;
int parent_index_ = -1;
int base_index_ = -1;
double start_level_score_ = 0;
bool is_manual_ = false;
CompactionInputFiles start_level_inputs_;
std::vector<CompactionInputFiles> compaction_inputs_;
CompactionInputFiles output_level_inputs_;
std::vector<FileMetaData*> grandparents_;
CompactionReason compaction_reason_ = CompactionReason::kUnknown;
const MutableCFOptions& mutable_cf_options_;
const ImmutableCFOptions& ioptions_;
// Pick a path ID to place a newly generated file, with its level
static uint32_t GetPathId(const ImmutableCFOptions& ioptions,
const MutableCFOptions& mutable_cf_options,
int level);
static const int kMinFilesForIntraL0Compaction = 4;
};
void LevelCompactionBuilder::PickExpiredTtlFiles() {
if (vstorage_->ExpiredTtlFiles().empty()) {
return;
}
auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
// If it's being compacted it has nothing to do here.
// If this assert() fails that means that some function marked some
// files as being_compacted, but didn't call ComputeCompactionScore()
assert(!level_file.second->being_compacted);
start_level_ = level_file.first;
output_level_ =
(start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
if ((start_level_ == vstorage_->num_non_empty_levels() - 1) ||
(start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty())) {
return false;
}
start_level_inputs_.files = {level_file.second};
start_level_inputs_.level = start_level_;
return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_);
};
for (auto& level_file : vstorage_->ExpiredTtlFiles()) {
if (continuation(level_file)) {
// found the compaction!
return;
}
}
start_level_inputs_.files.clear();
}
void LevelCompactionBuilder::PickFilesMarkedForPeriodicCompaction() {
if (vstorage_->FilesMarkedForPeriodicCompaction().empty()) {
return;
}
auto continuation = [&](std::pair<int, FileMetaData*> level_file) {
// If it's being compacted it has nothing to do here.
// If this assert() fails that means that some function marked some
// files as being_compacted, but didn't call ComputeCompactionScore()
assert(!level_file.second->being_compacted);
output_level_ = start_level_ = level_file.first;
if (start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty()) {
return false;
}
start_level_inputs_.files = {level_file.second};
start_level_inputs_.level = start_level_;
return compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_);
};
for (auto& level_file : vstorage_->FilesMarkedForPeriodicCompaction()) {
if (continuation(level_file)) {
// found the compaction!
return;
}
}
start_level_inputs_.files.clear();
}
void LevelCompactionBuilder::SetupInitialFiles() {
// Find the compactions by size on all levels.
bool skipped_l0_to_base = false;
for (int i = 0; i < compaction_picker_->NumberLevels() - 1; i++) {
start_level_score_ = vstorage_->CompactionScore(i);
start_level_ = vstorage_->CompactionScoreLevel(i);
assert(i == 0 || start_level_score_ <= vstorage_->CompactionScore(i - 1));
if (start_level_score_ >= 1) {
if (skipped_l0_to_base && start_level_ == vstorage_->base_level()) {
// If L0->base_level compaction is pending, don't schedule further
// compaction from base level. Otherwise L0->base_level compaction
// may starve.
continue;
}
output_level_ =
(start_level_ == 0) ? vstorage_->base_level() : start_level_ + 1;
if (PickFileToCompact()) {
// found the compaction!
if (start_level_ == 0) {
// L0 score = `num L0 files` / `level0_file_num_compaction_trigger`
compaction_reason_ = CompactionReason::kLevelL0FilesNum;
} else {
// L1+ score = `Level files size` / `MaxBytesForLevel`
compaction_reason_ = CompactionReason::kLevelMaxLevelSize;
}
break;
} else {
// didn't find the compaction, clear the inputs
start_level_inputs_.clear();
if (start_level_ == 0) {
skipped_l0_to_base = true;
// L0->base_level may be blocked due to ongoing L0->base_level
// compactions. It may also be blocked by an ongoing compaction from
// base_level downwards.
//
// In these cases, to reduce L0 file count and thus reduce likelihood
// of write stalls, we can attempt compacting a span of files within
// L0.
if (PickIntraL0Compaction()) {
output_level_ = 0;
compaction_reason_ = CompactionReason::kLevelL0FilesNum;
break;
}
}
}
}
}
// if we didn't find a compaction, check if there are any files marked for
// compaction
if (start_level_inputs_.empty()) {
parent_index_ = base_index_ = -1;
compaction_picker_->PickFilesMarkedForCompaction(
cf_name_, vstorage_, &start_level_, &output_level_,
&start_level_inputs_);
if (!start_level_inputs_.empty()) {
is_manual_ = true;
compaction_reason_ = CompactionReason::kFilesMarkedForCompaction;
return;
}
}
// Bottommost Files Compaction on deleting tombstones
if (start_level_inputs_.empty()) {
size_t i;
for (i = 0; i < vstorage_->BottommostFilesMarkedForCompaction().size();
++i) {
auto& level_and_file = vstorage_->BottommostFilesMarkedForCompaction()[i];
assert(!level_and_file.second->being_compacted);
start_level_inputs_.level = output_level_ = start_level_ =
level_and_file.first;
start_level_inputs_.files = {level_and_file.second};
if (compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_)) {
break;
}
}
if (i == vstorage_->BottommostFilesMarkedForCompaction().size()) {
start_level_inputs_.clear();
} else {
assert(!start_level_inputs_.empty());
compaction_reason_ = CompactionReason::kBottommostFiles;
return;
}
}
// TTL Compaction
if (start_level_inputs_.empty()) {
PickExpiredTtlFiles();
if (!start_level_inputs_.empty()) {
compaction_reason_ = CompactionReason::kTtl;
return;
}
}
// Periodic Compaction
if (start_level_inputs_.empty()) {
PickFilesMarkedForPeriodicCompaction();
if (!start_level_inputs_.empty()) {
compaction_reason_ = CompactionReason::kPeriodicCompaction;
return;
}
}
}
bool LevelCompactionBuilder::SetupOtherL0FilesIfNeeded() {
if (start_level_ == 0 && output_level_ != 0) {
return compaction_picker_->GetOverlappingL0Files(
vstorage_, &start_level_inputs_, output_level_, &parent_index_);
}
return true;
}
bool LevelCompactionBuilder::SetupOtherInputsIfNeeded() {
// Setup input files from output level. For output to L0, we only compact
// spans of files that do not interact with any pending compactions, so don't
// need to consider other levels.
if (output_level_ != 0) {
output_level_inputs_.level = output_level_;
if (!compaction_picker_->SetupOtherInputs(
cf_name_, mutable_cf_options_, vstorage_, &start_level_inputs_,
&output_level_inputs_, &parent_index_, base_index_)) {
return false;
}
compaction_inputs_.push_back(start_level_inputs_);
if (!output_level_inputs_.empty()) {
compaction_inputs_.push_back(output_level_inputs_);
}
// In some edge cases we could pick a compaction that will be compacting
// a key range that overlap with another running compaction, and both
// of them have the same output level. This could happen if
// (1) we are running a non-exclusive manual compaction
// (2) AddFile ingest a new file into the LSM tree
// We need to disallow this from happening.
if (compaction_picker_->FilesRangeOverlapWithCompaction(compaction_inputs_,
output_level_)) {
// This compaction output could potentially conflict with the output
// of a currently running compaction, we cannot run it.
return false;
}
compaction_picker_->GetGrandparents(vstorage_, start_level_inputs_,
output_level_inputs_, &grandparents_);
} else {
compaction_inputs_.push_back(start_level_inputs_);
}
return true;
}
Compaction* LevelCompactionBuilder::PickCompaction() {
// Pick up the first file to start compaction. It may have been extended
// to a clean cut.
SetupInitialFiles();
if (start_level_inputs_.empty()) {
return nullptr;
}
assert(start_level_ >= 0 && output_level_ >= 0);
// If it is a L0 -> base level compaction, we need to set up other L0
// files if needed.
if (!SetupOtherL0FilesIfNeeded()) {
return nullptr;
}
// Pick files in the output level and expand more files in the start level
// if needed.
if (!SetupOtherInputsIfNeeded()) {
return nullptr;
}
// Form a compaction object containing the files we picked.
Compaction* c = GetCompaction();
TEST_SYNC_POINT_CALLBACK("LevelCompactionPicker::PickCompaction:Return", c);
return c;
}
Compaction* LevelCompactionBuilder::GetCompaction() {
auto c = new Compaction(
vstorage_, ioptions_, mutable_cf_options_, std::move(compaction_inputs_),
output_level_,
MaxFileSizeForLevel(mutable_cf_options_, output_level_,
ioptions_.compaction_style, vstorage_->base_level(),
ioptions_.level_compaction_dynamic_level_bytes),
mutable_cf_options_.max_compaction_bytes,
GetPathId(ioptions_, mutable_cf_options_, output_level_),
GetCompressionType(ioptions_, vstorage_, mutable_cf_options_,
output_level_, vstorage_->base_level()),
GetCompressionOptions(ioptions_, vstorage_, output_level_),
/* max_subcompactions */ 0, std::move(grandparents_), is_manual_,
start_level_score_, false /* deletion_compaction */, compaction_reason_);
// If it's level 0 compaction, make sure we don't execute any other level 0
// compactions in parallel
compaction_picker_->RegisterCompaction(c);
// 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
vstorage_->ComputeCompactionScore(ioptions_, mutable_cf_options_);
return c;
}
/*
* Find the optimal path to place a file
* Given a level, finds the path where levels up to it will fit in levels
* up to and including this path
*/
uint32_t LevelCompactionBuilder::GetPathId(
const ImmutableCFOptions& ioptions,
const MutableCFOptions& mutable_cf_options, int level) {
uint32_t p = 0;
assert(!ioptions.cf_paths.empty());
// size remaining in the most recent path
uint64_t current_path_size = ioptions.cf_paths[0].target_size;
uint64_t level_size;
int cur_level = 0;
// max_bytes_for_level_base denotes L1 size.
// We estimate L0 size to be the same as L1.
level_size = mutable_cf_options.max_bytes_for_level_base;
// Last path is the fallback
while (p < ioptions.cf_paths.size() - 1) {
if (level_size <= current_path_size) {
if (cur_level == level) {
// Does desired level fit in this path?
return p;
} else {
current_path_size -= level_size;
if (cur_level > 0) {
if (ioptions.level_compaction_dynamic_level_bytes) {
// Currently, level_compaction_dynamic_level_bytes is ignored when
// multiple db paths are specified. https://github.com/facebook/
// rocksdb/blob/master/db/column_family.cc.
// Still, adding this check to avoid accidentally using
// max_bytes_for_level_multiplier_additional
level_size = static_cast<uint64_t>(
level_size * mutable_cf_options.max_bytes_for_level_multiplier);
} else {
level_size = static_cast<uint64_t>(
level_size * mutable_cf_options.max_bytes_for_level_multiplier *
mutable_cf_options.MaxBytesMultiplerAdditional(cur_level));
}
}
cur_level++;
continue;
}
}
p++;
current_path_size = ioptions.cf_paths[p].target_size;
}
return p;
}
bool LevelCompactionBuilder::PickFileToCompact() {
// level 0 files are overlapping. So we cannot pick more
// than one concurrent compactions at this level. This
// could be made better by looking at key-ranges that are
// being compacted at level 0.
if (start_level_ == 0 &&
!compaction_picker_->level0_compactions_in_progress()->empty()) {
TEST_SYNC_POINT("LevelCompactionPicker::PickCompactionBySize:0");
return false;
}
start_level_inputs_.clear();
assert(start_level_ >= 0);
// Pick the largest file in this level that is not already
// being compacted
const std::vector<int>& file_size =
vstorage_->FilesByCompactionPri(start_level_);
const std::vector<FileMetaData*>& level_files =
vstorage_->LevelFiles(start_level_);
unsigned int cmp_idx;
for (cmp_idx = vstorage_->NextCompactionIndex(start_level_);
cmp_idx < file_size.size(); cmp_idx++) {
int index = file_size[cmp_idx];
auto* f = level_files[index];
// do not pick a file to compact if it is being compacted
// from n-1 level.
if (f->being_compacted) {
continue;
}
start_level_inputs_.files.push_back(f);
start_level_inputs_.level = start_level_;
if (!compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&start_level_inputs_) ||
compaction_picker_->FilesRangeOverlapWithCompaction(
{start_level_inputs_}, output_level_)) {
// A locked (pending compaction) input-level file was pulled in due to
// user-key overlap.
start_level_inputs_.clear();
continue;
}
// Now that input level is fully expanded, we check whether any output files
// are locked due to pending compaction.
//
// Note we rely on ExpandInputsToCleanCut() to tell us whether any output-
// level files are locked, not just the extra ones pulled in for user-key
// overlap.
InternalKey smallest, largest;
compaction_picker_->GetRange(start_level_inputs_, &smallest, &largest);
CompactionInputFiles output_level_inputs;
output_level_inputs.level = output_level_;
vstorage_->GetOverlappingInputs(output_level_, &smallest, &largest,
&output_level_inputs.files);
if (!output_level_inputs.empty() &&
!compaction_picker_->ExpandInputsToCleanCut(cf_name_, vstorage_,
&output_level_inputs)) {
start_level_inputs_.clear();
continue;
}
base_index_ = index;
break;
}
// store where to start the iteration in the next call to PickCompaction
vstorage_->SetNextCompactionIndex(start_level_, cmp_idx);
return start_level_inputs_.size() > 0;
}
bool LevelCompactionBuilder::PickIntraL0Compaction() {
start_level_inputs_.clear();
const std::vector<FileMetaData*>& level_files =
vstorage_->LevelFiles(0 /* level */);
if (level_files.size() <
static_cast<size_t>(
mutable_cf_options_.level0_file_num_compaction_trigger + 2) ||
level_files[0]->being_compacted) {
// If L0 isn't accumulating much files beyond the regular trigger, don't
// resort to L0->L0 compaction yet.
return false;
}
return FindIntraL0Compaction(
level_files, kMinFilesForIntraL0Compaction, port::kMaxUint64,
mutable_cf_options_.max_compaction_bytes, &start_level_inputs_);
}
} // namespace
Compaction* LevelCompactionPicker::PickCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
VersionStorageInfo* vstorage, LogBuffer* log_buffer) {
LevelCompactionBuilder builder(cf_name, vstorage, this, log_buffer,
mutable_cf_options, ioptions_);
return builder.PickCompaction();
}
} // namespace rocksdb

32
db/compaction_picker_level.h Normal file
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@ -0,0 +1,32 @@
// 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.
#pragma once
#include "db/compaction_picker.h"
namespace rocksdb {
// Picking compactions for leveled compaction. See wiki page
// https://github.com/facebook/rocksdb/wiki/Leveled-Compaction
// for description of Leveled compaction.
class LevelCompactionPicker : public CompactionPicker {
public:
LevelCompactionPicker(const ImmutableCFOptions& ioptions,
const InternalKeyComparator* icmp)
: CompactionPicker(ioptions, icmp) {}
virtual Compaction* PickCompaction(const std::string& cf_name,
const MutableCFOptions& mutable_cf_options,
VersionStorageInfo* vstorage,
LogBuffer* log_buffer) override;
virtual bool NeedsCompaction(
const VersionStorageInfo* vstorage) const override;
};
} // namespace rocksdb

1
db/compaction_picker_test.cc
View File

@ -10,6 +10,7 @@
#include <utility>
#include "db/compaction.h"
#include "db/compaction_picker_fifo.h"
#include "db/compaction_picker_level.h"
#include "db/compaction_picker_universal.h"
#include "test_util/testharness.h"

1
src.mk
View File

@ -12,6 +12,7 @@ LIB_SOURCES = \
db/compaction_job.cc \
db/compaction_picker.cc \
db/compaction_picker_fifo.cc \
db/compaction_picker_level.cc \
db/compaction_picker_universal.cc \
db/convenience.cc \
db/db_filesnapshot.cc \