// 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/compaction_picker_fifo.h"
#include <cinttypes>
#include <string>
#include <vector>
#include "db/column_family.h"
#include "logging/log_buffer.h"
#include "logging/logging.h"
#include "options/options_helper.h"
#include "util/string_util.h"
namespace ROCKSDB_NAMESPACE {
namespace {
uint64_t GetTotalFilesSize(const std::vector<FileMetaData*>& files) {
uint64_t total_size = 0;
for (const auto& f : files) {
total_size += f->fd.file_size;
}
return total_size;
}
} // anonymous namespace
bool FIFOCompactionPicker::NeedsCompaction(
const VersionStorageInfo* vstorage) const {
const int kLevel0 = 0;
return vstorage->CompactionScore(kLevel0) >= 1;
}
Compaction* FIFOCompactionPicker::PickTTLCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
LogBuffer* log_buffer) {
assert(mutable_cf_options.ttl > 0);
const int kLevel0 = 0;
const std::vector<FileMetaData*>& level_files = vstorage->LevelFiles(kLevel0);
uint64_t total_size = GetTotalFilesSize(level_files);
int64_t _current_time;
auto status = ioptions_.clock->GetCurrentTime(&_current_time);
if (!status.ok()) {
ROCKS_LOG_BUFFER(log_buffer,
"[%s] FIFO compaction: Couldn't get current time: %s. "
"Not doing compactions based on TTL. ",
cf_name.c_str(), status.ToString().c_str());
return nullptr;
}
const uint64_t current_time = static_cast<uint64_t>(_current_time);
if (!level0_compactions_in_progress_.empty()) {
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: Already executing compaction. No need "
"to run parallel compactions since compactions are very fast",
cf_name.c_str());
return nullptr;
}
std::vector<CompactionInputFiles> inputs;
inputs.emplace_back();
inputs[0].level = 0;
// avoid underflow
if (current_time > mutable_cf_options.ttl) {
for (auto ritr = level_files.rbegin(); ritr != level_files.rend(); ++ritr) {
FileMetaData* f = *ritr;
assert(f);
if (f->fd.table_reader && f->fd.table_reader->GetTableProperties()) {
uint64_t creation_time =
f->fd.table_reader->GetTableProperties()->creation_time;
if (creation_time == 0 ||
creation_time >= (current_time - mutable_cf_options.ttl)) {
break;
}
}
total_size -= f->fd.file_size;
inputs[0].files.push_back(f);
}
}
// Return a nullptr and proceed to size-based FIFO compaction if:
// 1. there are no files older than ttl OR
// 2. there are a few files older than ttl, but deleting them will not bring
// the total size to be less than max_table_files_size threshold.
if (inputs[0].files.empty() ||
total_size >
mutable_cf_options.compaction_options_fifo.max_table_files_size) {
return nullptr;
}
for (const auto& f : inputs[0].files) {
uint64_t creation_time = 0;
assert(f);
if (f->fd.table_reader && f->fd.table_reader->GetTableProperties()) {
creation_time = f->fd.table_reader->GetTableProperties()->creation_time;
}
ROCKS_LOG_BUFFER(log_buffer,
"[%s] FIFO compaction: picking file %" PRIu64
" with creation time %" PRIu64 " for deletion",
cf_name.c_str(), f->fd.GetNumber(), creation_time);
}
Compaction* c = new Compaction(
vstorage, ioptions_, mutable_cf_options, mutable_db_options,
std::move(inputs), 0, 0, 0, 0, kNoCompression,
mutable_cf_options.compression_opts, Temperature::kUnknown,
/* max_subcompactions */ 0, {}, /* is manual */ false,
/* trim_ts */ "", vstorage->CompactionScore(0),
/* is deletion compaction */ true, /* l0_files_might_overlap */ true,
CompactionReason::kFIFOTtl);
return c;
}
// The size-based compaction picker for FIFO.
//
// When the entire column family size exceeds max_table_files_size, FIFO will
// try to delete the oldest sst file(s) until the resulting column family size
// is smaller than max_table_files_size.
//
// This function also takes care the case where a DB is migrating from level /
// universal compaction to FIFO compaction. During the migration, the column
// family will also have non-L0 files while FIFO can only create L0 files.
// In this case, this function will first purge the sst files in the bottom-
// most non-empty level first, and the DB will eventually converge to the
// regular FIFO case where there're only L0 files. Note that during the
// migration case, the purge order will only be an approximation of "FIFO"
// as entries inside lower-level files might sometimes be newer than some
// entries inside upper-level files.
Compaction* FIFOCompactionPicker::PickSizeCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
LogBuffer* log_buffer) {
// compute the total size and identify the last non-empty level
int last_level = 0;
uint64_t total_size = 0;
for (int level = 0; level < vstorage->num_levels(); ++level) {
auto level_size = GetTotalFilesSize(vstorage->LevelFiles(level));
total_size += level_size;
if (level_size > 0) {
last_level = level;
}
}
const std::vector<FileMetaData*>& last_level_files =
vstorage->LevelFiles(last_level);
if (last_level == 0 &&
total_size <=
mutable_cf_options.compaction_options_fifo.max_table_files_size) {
// total size not exceeded, try to find intra level 0 compaction if enabled
const std::vector<FileMetaData*>& level0_files = vstorage->LevelFiles(0);
if (mutable_cf_options.compaction_options_fifo.allow_compaction &&
level0_files.size() > 0) {
CompactionInputFiles comp_inputs;
// try to prevent same files from being compacted multiple times, which
// could produce large files that may never TTL-expire. Achieve this by
// disallowing compactions with files larger than memtable (inflate its
// size by 10% to account for uncompressed L0 files that may have size
// slightly greater than memtable size limit).
size_t max_compact_bytes_per_del_file =
static_cast<size_t>(MultiplyCheckOverflow(
static_cast<uint64_t>(mutable_cf_options.write_buffer_size),
1.1));
if (FindIntraL0Compaction(
level0_files,
mutable_cf_options
.level0_file_num_compaction_trigger /* min_files_to_compact */
,
max_compact_bytes_per_del_file,
mutable_cf_options.max_compaction_bytes, &comp_inputs)) {
Compaction* c = new Compaction(
vstorage, ioptions_, mutable_cf_options, mutable_db_options,
{comp_inputs}, 0, 16 * 1024 * 1024 /* output file size limit */,
0 /* max compaction bytes, not applicable */,
0 /* output path ID */, mutable_cf_options.compression,
mutable_cf_options.compression_opts, Temperature::kUnknown,
0 /* max_subcompactions */, {}, /* is manual */ false,
/* trim_ts */ "", vstorage->CompactionScore(0),
/* is deletion compaction */ false,
/* l0_files_might_overlap */ true,
CompactionReason::kFIFOReduceNumFiles);
return c;
}
}
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: nothing to do. Total size %" PRIu64
", max size %" PRIu64 "\n",
cf_name.c_str(), total_size,
mutable_cf_options.compaction_options_fifo.max_table_files_size);
return nullptr;
}
if (!level0_compactions_in_progress_.empty()) {
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: Already executing compaction. No need "
"to run parallel compactions since compactions are very fast",
cf_name.c_str());
return nullptr;
}
std::vector<CompactionInputFiles> inputs;
inputs.emplace_back();
inputs[0].level = last_level;
if (last_level == 0) {
// In L0, right-most files are the oldest files.
for (auto ritr = last_level_files.rbegin(); ritr != last_level_files.rend();
++ritr) {
auto f = *ritr;
total_size -= f->fd.file_size;
inputs[0].files.push_back(f);
char tmp_fsize[16];
AppendHumanBytes(f->fd.GetFileSize(), tmp_fsize, sizeof(tmp_fsize));
ROCKS_LOG_BUFFER(log_buffer,
"[%s] FIFO compaction: picking file %" PRIu64
" with size %s for deletion",
cf_name.c_str(), f->fd.GetNumber(), tmp_fsize);
if (total_size <=
mutable_cf_options.compaction_options_fifo.max_table_files_size) {
break;
}
}
} else if (total_size >
mutable_cf_options.compaction_options_fifo.max_table_files_size) {
// If the last level is non-L0, we actually don't know which file is
// logically the oldest since the file creation time only represents
// when this file was compacted to this level, which is independent
// to when the entries in this file were first inserted.
//
// As a result, we delete files from the left instead. This means the sst
// file with the smallest key will be deleted first. This design decision
// better serves a major type of FIFO use cases where smaller keys are
// associated with older data.
for (const auto& f : last_level_files) {
total_size -= f->fd.file_size;
inputs[0].files.push_back(f);
char tmp_fsize[16];
AppendHumanBytes(f->fd.GetFileSize(), tmp_fsize, sizeof(tmp_fsize));
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: picking file %" PRIu64
" with size %s for deletion under total size %" PRIu64
" vs max table files size %" PRIu64,
cf_name.c_str(), f->fd.GetNumber(), tmp_fsize, total_size,
mutable_cf_options.compaction_options_fifo.max_table_files_size);
if (total_size <=
mutable_cf_options.compaction_options_fifo.max_table_files_size) {
break;
}
}
} else {
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: nothing to do. Total size %" PRIu64
", max size %" PRIu64 "\n",
cf_name.c_str(), total_size,
mutable_cf_options.compaction_options_fifo.max_table_files_size);
return nullptr;
}
Compaction* c = new Compaction(
vstorage, ioptions_, mutable_cf_options, mutable_db_options,
std::move(inputs), last_level,
/* target_file_size */ 0,
/* max_compaction_bytes */ 0,
/* output_path_id */ 0, kNoCompression,
mutable_cf_options.compression_opts, Temperature::kUnknown,
/* max_subcompactions */ 0, {}, /* is manual */ false,
/* trim_ts */ "", vstorage->CompactionScore(0),
/* is deletion compaction */ true,
/* l0_files_might_overlap */ true, CompactionReason::kFIFOMaxSize);
return c;
}
Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
LogBuffer* log_buffer) {
const std::vector<FileTemperatureAge>& ages =
mutable_cf_options.compaction_options_fifo
.file_temperature_age_thresholds;
if (ages.empty()) {
return nullptr;
}
// Does not apply to multi-level FIFO.
if (vstorage->num_levels() > 1) {
return nullptr;
}
const int kLevel0 = 0;
const std::vector<FileMetaData*>& level_files = vstorage->LevelFiles(kLevel0);
if (level_files.empty()) {
return nullptr;
}
int64_t _current_time;
auto status = ioptions_.clock->GetCurrentTime(&_current_time);
if (!status.ok()) {
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: Couldn't get current time: %s. "
"Not doing compactions based on file temperature-age threshold. ",
cf_name.c_str(), status.ToString().c_str());
return nullptr;
}
const uint64_t current_time = static_cast<uint64_t>(_current_time);
if (!level0_compactions_in_progress_.empty()) {
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: Already executing compaction. Parallel "
"compactions are not supported",
cf_name.c_str());
return nullptr;
}
std::vector<CompactionInputFiles> inputs;
inputs.emplace_back();
inputs[0].level = 0;
// avoid underflow
uint64_t min_age = ages[0].age;
// kLastTemperature means target temperature is to be determined.
Temperature compaction_target_temp = Temperature::kLastTemperature;
if (current_time > min_age) {
uint64_t create_time_threshold = current_time - min_age;
uint64_t compaction_size = 0;
// We will ideally identify a file qualifying for temperature change by
// knowing the timestamp for the youngest entry in the file. However, right
// now we don't have the information. We infer it by looking at timestamp of
// the previous file's (which is just younger) oldest entry's timestamp.
Temperature cur_target_temp;
// avoid index underflow
assert(level_files.size() >= 1);
for (size_t index = level_files.size() - 1; index >= 1; --index) {
// Try to add cur_file to compaction inputs.
FileMetaData* cur_file = level_files[index];
// prev_file is just younger than cur_file
FileMetaData* prev_file = level_files[index - 1];
if (cur_file->being_compacted) {
// Should not happen since we check for
// `level0_compactions_in_progress_` above. Here we simply just don't
// schedule anything.
return nullptr;
}
uint64_t oldest_ancestor_time = prev_file->TryGetOldestAncesterTime();
if (oldest_ancestor_time == kUnknownOldestAncesterTime) {
// Older files might not have enough information. It is possible to
// handle these files by looking at newer files, but maintaining the
// logic isn't worth it.
break;
}
if (oldest_ancestor_time > create_time_threshold) {
// cur_file is too fresh
break;
}
cur_target_temp = ages[0].temperature;
for (size_t i = 1; i < ages.size(); ++i) {
if (current_time >= ages[i].age &&
oldest_ancestor_time <= current_time - ages[i].age) {
cur_target_temp = ages[i].temperature;
}
}
if (cur_file->temperature == cur_target_temp) {
if (inputs[0].empty()) {
continue;
} else {
break;
}
}
// cur_file needs to change temperature
if (compaction_target_temp == Temperature::kLastTemperature) {
assert(inputs[0].empty());
compaction_target_temp = cur_target_temp;
} else if (cur_target_temp != compaction_target_temp) {
assert(!inputs[0].empty());
break;
}
if (inputs[0].empty() || compaction_size + cur_file->fd.GetFileSize() <=
mutable_cf_options.max_compaction_bytes) {
inputs[0].files.push_back(cur_file);
compaction_size += cur_file->fd.GetFileSize();
ROCKS_LOG_BUFFER(
log_buffer,
"[%s] FIFO compaction: picking file %" PRIu64
" with next file's oldest time %" PRIu64 " for temperature %s.",
cf_name.c_str(), cur_file->fd.GetNumber(), oldest_ancestor_time,
temperature_to_string[cur_target_temp].c_str());
}
if (compaction_size > mutable_cf_options.max_compaction_bytes) {
break;
}
}
}
if (inputs[0].files.empty()) {
return nullptr;
}
Compaction* c = new Compaction(
vstorage, ioptions_, mutable_cf_options, mutable_db_options,
std::move(inputs), 0, 0 /* output file size limit */,
0 /* max compaction bytes, not applicable */, 0 /* output path ID */,
mutable_cf_options.compression, mutable_cf_options.compression_opts,
compaction_target_temp,
/* max_subcompactions */ 0, {}, /* is manual */ false, /* trim_ts */ "",
vstorage->CompactionScore(0),
/* is deletion compaction */ false, /* l0_files_might_overlap */ true,
CompactionReason::kChangeTemperature);
return c;
}
Compaction* FIFOCompactionPicker::PickCompaction(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
LogBuffer* log_buffer) {
Compaction* c = nullptr;
if (mutable_cf_options.ttl > 0) {
c = PickTTLCompaction(cf_name, mutable_cf_options, mutable_db_options,
vstorage, log_buffer);
}
if (c == nullptr) {
c = PickSizeCompaction(cf_name, mutable_cf_options, mutable_db_options,
vstorage, log_buffer);
}
if (c == nullptr) {
c = PickTemperatureChangeCompaction(
cf_name, mutable_cf_options, mutable_db_options, vstorage, log_buffer);
}
RegisterCompaction(c);
return c;
}
Compaction* FIFOCompactionPicker::CompactRange(
const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
int input_level, int output_level,
const CompactRangeOptions& /*compact_range_options*/,
const InternalKey* /*begin*/, const InternalKey* /*end*/,
InternalKey** compaction_end, bool* /*manual_conflict*/,
uint64_t /*max_file_num_to_ignore*/, const std::string& /*trim_ts*/) {
#ifdef NDEBUG
(void)input_level;
(void)output_level;
#endif
assert(input_level == 0);
assert(output_level == 0);
*compaction_end = nullptr;
LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, ioptions_.logger);
Compaction* c = PickCompaction(cf_name, mutable_cf_options,
mutable_db_options, vstorage, &log_buffer);
log_buffer.FlushBufferToLog();
return c;
}
} // namespace ROCKSDB_NAMESPACE