rocksdb/options/options.cc
Maysam Yabandeh 6a40ee5eb1 Refresh snapshot list during long compactions (2nd attempt) (#5278)
Summary:
Part of compaction cpu goes to processing snapshot list, the larger the list the bigger the overhead. Although the lifetime of most of the snapshots is much shorter than the lifetime of compactions, the compaction conservatively operates on the list of snapshots that it initially obtained. This patch allows the snapshot list to be updated via a callback if the compaction is taking long. This should let the compaction to continue more efficiently with much smaller snapshot list.
For simplicity, to avoid the feature is disabled in two cases: i) When more than one sub-compaction are sharing the same snapshot list, ii) when Range Delete is used in which the range delete aggregator has its own copy of snapshot list.
This fixes the reverted https://github.com/facebook/rocksdb/pull/5099 issue with range deletes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5278

Differential Revision: D15203291

Pulled By: maysamyabandeh

fbshipit-source-id: fa645611e606aa222c7ce53176dc5bb6f259c258
2019-05-03 17:30:22 -07:00

624 lines
26 KiB
C++

// 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 "rocksdb/options.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <limits>
#include "monitoring/statistics.h"
#include "options/db_options.h"
#include "options/options_helper.h"
#include "rocksdb/cache.h"
#include "rocksdb/compaction_filter.h"
#include "rocksdb/comparator.h"
#include "rocksdb/env.h"
#include "rocksdb/memtablerep.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/slice.h"
#include "rocksdb/slice_transform.h"
#include "rocksdb/sst_file_manager.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
#include "rocksdb/wal_filter.h"
#include "table/block_based_table_factory.h"
#include "util/compression.h"
namespace rocksdb {
AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions() {
assert(memtable_factory.get() != nullptr);
}
AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions(const Options& options)
: max_write_buffer_number(options.max_write_buffer_number),
min_write_buffer_number_to_merge(
options.min_write_buffer_number_to_merge),
max_write_buffer_number_to_maintain(
options.max_write_buffer_number_to_maintain),
inplace_update_support(options.inplace_update_support),
inplace_update_num_locks(options.inplace_update_num_locks),
inplace_callback(options.inplace_callback),
memtable_prefix_bloom_size_ratio(
options.memtable_prefix_bloom_size_ratio),
memtable_whole_key_filtering(options.memtable_whole_key_filtering),
memtable_huge_page_size(options.memtable_huge_page_size),
memtable_insert_with_hint_prefix_extractor(
options.memtable_insert_with_hint_prefix_extractor),
bloom_locality(options.bloom_locality),
arena_block_size(options.arena_block_size),
compression_per_level(options.compression_per_level),
num_levels(options.num_levels),
level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
level0_stop_writes_trigger(options.level0_stop_writes_trigger),
target_file_size_base(options.target_file_size_base),
target_file_size_multiplier(options.target_file_size_multiplier),
level_compaction_dynamic_level_bytes(
options.level_compaction_dynamic_level_bytes),
max_bytes_for_level_multiplier(options.max_bytes_for_level_multiplier),
max_bytes_for_level_multiplier_additional(
options.max_bytes_for_level_multiplier_additional),
max_compaction_bytes(options.max_compaction_bytes),
soft_pending_compaction_bytes_limit(
options.soft_pending_compaction_bytes_limit),
hard_pending_compaction_bytes_limit(
options.hard_pending_compaction_bytes_limit),
compaction_style(options.compaction_style),
compaction_pri(options.compaction_pri),
compaction_options_universal(options.compaction_options_universal),
compaction_options_fifo(options.compaction_options_fifo),
max_sequential_skip_in_iterations(
options.max_sequential_skip_in_iterations),
memtable_factory(options.memtable_factory),
table_properties_collector_factories(
options.table_properties_collector_factories),
max_successive_merges(options.max_successive_merges),
optimize_filters_for_hits(options.optimize_filters_for_hits),
paranoid_file_checks(options.paranoid_file_checks),
force_consistency_checks(options.force_consistency_checks),
report_bg_io_stats(options.report_bg_io_stats),
ttl(options.ttl),
periodic_compaction_seconds(options.periodic_compaction_seconds),
sample_for_compression(options.sample_for_compression) {
assert(memtable_factory.get() != nullptr);
if (max_bytes_for_level_multiplier_additional.size() <
static_cast<unsigned int>(num_levels)) {
max_bytes_for_level_multiplier_additional.resize(num_levels, 1);
}
}
ColumnFamilyOptions::ColumnFamilyOptions()
: compression(Snappy_Supported() ? kSnappyCompression : kNoCompression),
table_factory(
std::shared_ptr<TableFactory>(new BlockBasedTableFactory())) {}
ColumnFamilyOptions::ColumnFamilyOptions(const Options& options)
: ColumnFamilyOptions(*static_cast<const ColumnFamilyOptions*>(&options)) {}
DBOptions::DBOptions() {}
DBOptions::DBOptions(const Options& options)
: DBOptions(*static_cast<const DBOptions*>(&options)) {}
void DBOptions::Dump(Logger* log) const {
ImmutableDBOptions(*this).Dump(log);
MutableDBOptions(*this).Dump(log);
} // DBOptions::Dump
void ColumnFamilyOptions::Dump(Logger* log) const {
ROCKS_LOG_HEADER(log, " Options.comparator: %s",
comparator->Name());
ROCKS_LOG_HEADER(log, " Options.merge_operator: %s",
merge_operator ? merge_operator->Name() : "None");
ROCKS_LOG_HEADER(log, " Options.compaction_filter: %s",
compaction_filter ? compaction_filter->Name() : "None");
ROCKS_LOG_HEADER(
log, " Options.compaction_filter_factory: %s",
compaction_filter_factory ? compaction_filter_factory->Name() : "None");
ROCKS_LOG_HEADER(log, " Options.memtable_factory: %s",
memtable_factory->Name());
ROCKS_LOG_HEADER(log, " Options.table_factory: %s",
table_factory->Name());
ROCKS_LOG_HEADER(log, " table_factory options: %s",
table_factory->GetPrintableTableOptions().c_str());
ROCKS_LOG_HEADER(log, " Options.write_buffer_size: %" ROCKSDB_PRIszt,
write_buffer_size);
ROCKS_LOG_HEADER(log, " Options.max_write_buffer_number: %d",
max_write_buffer_number);
if (!compression_per_level.empty()) {
for (unsigned int i = 0; i < compression_per_level.size(); i++) {
ROCKS_LOG_HEADER(
log, " Options.compression[%d]: %s", i,
CompressionTypeToString(compression_per_level[i]).c_str());
}
} else {
ROCKS_LOG_HEADER(log, " Options.compression: %s",
CompressionTypeToString(compression).c_str());
}
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression: %s",
bottommost_compression == kDisableCompressionOption
? "Disabled"
: CompressionTypeToString(bottommost_compression).c_str());
ROCKS_LOG_HEADER(
log, " Options.prefix_extractor: %s",
prefix_extractor == nullptr ? "nullptr" : prefix_extractor->Name());
ROCKS_LOG_HEADER(log,
" Options.memtable_insert_with_hint_prefix_extractor: %s",
memtable_insert_with_hint_prefix_extractor == nullptr
? "nullptr"
: memtable_insert_with_hint_prefix_extractor->Name());
ROCKS_LOG_HEADER(log, " Options.num_levels: %d", num_levels);
ROCKS_LOG_HEADER(log, " Options.min_write_buffer_number_to_merge: %d",
min_write_buffer_number_to_merge);
ROCKS_LOG_HEADER(log, " Options.max_write_buffer_number_to_maintain: %d",
max_write_buffer_number_to_maintain);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.window_bits: %d",
bottommost_compression_opts.window_bits);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.level: %d",
bottommost_compression_opts.level);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.strategy: %d",
bottommost_compression_opts.strategy);
ROCKS_LOG_HEADER(
log,
" Options.bottommost_compression_opts.max_dict_bytes: "
"%" PRIu32,
bottommost_compression_opts.max_dict_bytes);
ROCKS_LOG_HEADER(
log,
" Options.bottommost_compression_opts.zstd_max_train_bytes: "
"%" PRIu32,
bottommost_compression_opts.zstd_max_train_bytes);
ROCKS_LOG_HEADER(
log, " Options.bottommost_compression_opts.enabled: %s",
bottommost_compression_opts.enabled ? "true" : "false");
ROCKS_LOG_HEADER(log, " Options.compression_opts.window_bits: %d",
compression_opts.window_bits);
ROCKS_LOG_HEADER(log, " Options.compression_opts.level: %d",
compression_opts.level);
ROCKS_LOG_HEADER(log, " Options.compression_opts.strategy: %d",
compression_opts.strategy);
ROCKS_LOG_HEADER(
log,
" Options.compression_opts.max_dict_bytes: %" PRIu32,
compression_opts.max_dict_bytes);
ROCKS_LOG_HEADER(log,
" Options.compression_opts.zstd_max_train_bytes: "
"%" PRIu32,
compression_opts.zstd_max_train_bytes);
ROCKS_LOG_HEADER(log,
" Options.compression_opts.enabled: %s",
compression_opts.enabled ? "true" : "false");
ROCKS_LOG_HEADER(log, " Options.level0_file_num_compaction_trigger: %d",
level0_file_num_compaction_trigger);
ROCKS_LOG_HEADER(log, " Options.level0_slowdown_writes_trigger: %d",
level0_slowdown_writes_trigger);
ROCKS_LOG_HEADER(log, " Options.level0_stop_writes_trigger: %d",
level0_stop_writes_trigger);
ROCKS_LOG_HEADER(
log, " Options.target_file_size_base: %" PRIu64,
target_file_size_base);
ROCKS_LOG_HEADER(log, " Options.target_file_size_multiplier: %d",
target_file_size_multiplier);
ROCKS_LOG_HEADER(
log, " Options.max_bytes_for_level_base: %" PRIu64,
max_bytes_for_level_base);
ROCKS_LOG_HEADER(
log, " Options.snap_refresh_nanos: %" PRIu64,
snap_refresh_nanos);
ROCKS_LOG_HEADER(log, "Options.level_compaction_dynamic_level_bytes: %d",
level_compaction_dynamic_level_bytes);
ROCKS_LOG_HEADER(log, " Options.max_bytes_for_level_multiplier: %f",
max_bytes_for_level_multiplier);
for (size_t i = 0; i < max_bytes_for_level_multiplier_additional.size();
i++) {
ROCKS_LOG_HEADER(
log, "Options.max_bytes_for_level_multiplier_addtl[%" ROCKSDB_PRIszt
"]: %d",
i, max_bytes_for_level_multiplier_additional[i]);
}
ROCKS_LOG_HEADER(
log, " Options.max_sequential_skip_in_iterations: %" PRIu64,
max_sequential_skip_in_iterations);
ROCKS_LOG_HEADER(
log, " Options.max_compaction_bytes: %" PRIu64,
max_compaction_bytes);
ROCKS_LOG_HEADER(
log,
" Options.arena_block_size: %" ROCKSDB_PRIszt,
arena_block_size);
ROCKS_LOG_HEADER(log,
" Options.soft_pending_compaction_bytes_limit: %" PRIu64,
soft_pending_compaction_bytes_limit);
ROCKS_LOG_HEADER(log,
" Options.hard_pending_compaction_bytes_limit: %" PRIu64,
hard_pending_compaction_bytes_limit);
ROCKS_LOG_HEADER(log, " Options.rate_limit_delay_max_milliseconds: %u",
rate_limit_delay_max_milliseconds);
ROCKS_LOG_HEADER(log, " Options.disable_auto_compactions: %d",
disable_auto_compactions);
const auto& it_compaction_style =
compaction_style_to_string.find(compaction_style);
std::string str_compaction_style;
if (it_compaction_style == compaction_style_to_string.end()) {
assert(false);
str_compaction_style = "unknown_" + std::to_string(compaction_style);
} else {
str_compaction_style = it_compaction_style->second;
}
ROCKS_LOG_HEADER(log,
" Options.compaction_style: %s",
str_compaction_style.c_str());
const auto& it_compaction_pri =
compaction_pri_to_string.find(compaction_pri);
std::string str_compaction_pri;
if (it_compaction_pri == compaction_pri_to_string.end()) {
assert(false);
str_compaction_pri = "unknown_" + std::to_string(compaction_pri);
} else {
str_compaction_pri = it_compaction_pri->second;
}
ROCKS_LOG_HEADER(log,
" Options.compaction_pri: %s",
str_compaction_pri.c_str());
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.size_ratio: %u",
compaction_options_universal.size_ratio);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.min_merge_width: %u",
compaction_options_universal.min_merge_width);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.max_merge_width: %u",
compaction_options_universal.max_merge_width);
ROCKS_LOG_HEADER(
log,
"Options.compaction_options_universal."
"max_size_amplification_percent: %u",
compaction_options_universal.max_size_amplification_percent);
ROCKS_LOG_HEADER(
log,
"Options.compaction_options_universal.compression_size_percent: %d",
compaction_options_universal.compression_size_percent);
const auto& it_compaction_stop_style = compaction_stop_style_to_string.find(
compaction_options_universal.stop_style);
std::string str_compaction_stop_style;
if (it_compaction_stop_style == compaction_stop_style_to_string.end()) {
assert(false);
str_compaction_stop_style =
"unknown_" + std::to_string(compaction_options_universal.stop_style);
} else {
str_compaction_stop_style = it_compaction_stop_style->second;
}
ROCKS_LOG_HEADER(log,
"Options.compaction_options_universal.stop_style: %s",
str_compaction_stop_style.c_str());
ROCKS_LOG_HEADER(
log, "Options.compaction_options_fifo.max_table_files_size: %" PRIu64,
compaction_options_fifo.max_table_files_size);
ROCKS_LOG_HEADER(log,
"Options.compaction_options_fifo.allow_compaction: %d",
compaction_options_fifo.allow_compaction);
std::string collector_names;
for (const auto& collector_factory : table_properties_collector_factories) {
collector_names.append(collector_factory->Name());
collector_names.append("; ");
}
ROCKS_LOG_HEADER(
log, " Options.table_properties_collectors: %s",
collector_names.c_str());
ROCKS_LOG_HEADER(log,
" Options.inplace_update_support: %d",
inplace_update_support);
ROCKS_LOG_HEADER(
log,
" Options.inplace_update_num_locks: %" ROCKSDB_PRIszt,
inplace_update_num_locks);
// TODO: easier config for bloom (maybe based on avg key/value size)
ROCKS_LOG_HEADER(
log, " Options.memtable_prefix_bloom_size_ratio: %f",
memtable_prefix_bloom_size_ratio);
ROCKS_LOG_HEADER(log,
" Options.memtable_whole_key_filtering: %d",
memtable_whole_key_filtering);
ROCKS_LOG_HEADER(log, " Options.memtable_huge_page_size: %" ROCKSDB_PRIszt,
memtable_huge_page_size);
ROCKS_LOG_HEADER(log,
" Options.bloom_locality: %d",
bloom_locality);
ROCKS_LOG_HEADER(
log,
" Options.max_successive_merges: %" ROCKSDB_PRIszt,
max_successive_merges);
ROCKS_LOG_HEADER(log,
" Options.optimize_filters_for_hits: %d",
optimize_filters_for_hits);
ROCKS_LOG_HEADER(log, " Options.paranoid_file_checks: %d",
paranoid_file_checks);
ROCKS_LOG_HEADER(log, " Options.force_consistency_checks: %d",
force_consistency_checks);
ROCKS_LOG_HEADER(log, " Options.report_bg_io_stats: %d",
report_bg_io_stats);
ROCKS_LOG_HEADER(log, " Options.ttl: %" PRIu64,
ttl);
ROCKS_LOG_HEADER(log,
" Options.periodic_compaction_seconds: %" PRIu64,
periodic_compaction_seconds);
} // ColumnFamilyOptions::Dump
void Options::Dump(Logger* log) const {
DBOptions::Dump(log);
ColumnFamilyOptions::Dump(log);
} // Options::Dump
void Options::DumpCFOptions(Logger* log) const {
ColumnFamilyOptions::Dump(log);
} // Options::DumpCFOptions
//
// The goal of this method is to create a configuration that
// allows an application to write all files into L0 and
// then do a single compaction to output all files into L1.
Options*
Options::PrepareForBulkLoad()
{
// never slowdown ingest.
level0_file_num_compaction_trigger = (1<<30);
level0_slowdown_writes_trigger = (1<<30);
level0_stop_writes_trigger = (1<<30);
soft_pending_compaction_bytes_limit = 0;
hard_pending_compaction_bytes_limit = 0;
// no auto compactions please. The application should issue a
// manual compaction after all data is loaded into L0.
disable_auto_compactions = true;
// A manual compaction run should pick all files in L0 in
// a single compaction run.
max_compaction_bytes = (static_cast<uint64_t>(1) << 60);
// It is better to have only 2 levels, otherwise a manual
// compaction would compact at every possible level, thereby
// increasing the total time needed for compactions.
num_levels = 2;
// Need to allow more write buffers to allow more parallism
// of flushes.
max_write_buffer_number = 6;
min_write_buffer_number_to_merge = 1;
// When compaction is disabled, more parallel flush threads can
// help with write throughput.
max_background_flushes = 4;
// Prevent a memtable flush to automatically promote files
// to L1. This is helpful so that all files that are
// input to the manual compaction are all at L0.
max_background_compactions = 2;
// The compaction would create large files in L1.
target_file_size_base = 256 * 1024 * 1024;
return this;
}
Options* Options::OptimizeForSmallDb() {
// 16MB block cache
std::shared_ptr<Cache> cache = NewLRUCache(16 << 20);
ColumnFamilyOptions::OptimizeForSmallDb(&cache);
DBOptions::OptimizeForSmallDb(&cache);
return this;
}
Options* Options::OldDefaults(int rocksdb_major_version,
int rocksdb_minor_version) {
ColumnFamilyOptions::OldDefaults(rocksdb_major_version,
rocksdb_minor_version);
DBOptions::OldDefaults(rocksdb_major_version, rocksdb_minor_version);
return this;
}
DBOptions* DBOptions::OldDefaults(int rocksdb_major_version,
int rocksdb_minor_version) {
if (rocksdb_major_version < 4 ||
(rocksdb_major_version == 4 && rocksdb_minor_version < 7)) {
max_file_opening_threads = 1;
table_cache_numshardbits = 4;
}
if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version < 2)) {
delayed_write_rate = 2 * 1024U * 1024U;
} else if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version < 6)) {
delayed_write_rate = 16 * 1024U * 1024U;
}
max_open_files = 5000;
wal_recovery_mode = WALRecoveryMode::kTolerateCorruptedTailRecords;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OldDefaults(
int rocksdb_major_version, int rocksdb_minor_version) {
if (rocksdb_major_version < 5 ||
(rocksdb_major_version == 5 && rocksdb_minor_version <= 18)) {
compaction_pri = CompactionPri::kByCompensatedSize;
}
if (rocksdb_major_version < 4 ||
(rocksdb_major_version == 4 && rocksdb_minor_version < 7)) {
write_buffer_size = 4 << 20;
target_file_size_base = 2 * 1048576;
max_bytes_for_level_base = 10 * 1048576;
soft_pending_compaction_bytes_limit = 0;
hard_pending_compaction_bytes_limit = 0;
}
if (rocksdb_major_version < 5) {
level0_stop_writes_trigger = 24;
} else if (rocksdb_major_version == 5 && rocksdb_minor_version < 2) {
level0_stop_writes_trigger = 30;
}
return this;
}
// Optimization functions
DBOptions* DBOptions::OptimizeForSmallDb(std::shared_ptr<Cache>* cache) {
max_file_opening_threads = 1;
max_open_files = 5000;
// Cost memtable to block cache too.
std::shared_ptr<rocksdb::WriteBufferManager> wbm =
std::make_shared<rocksdb::WriteBufferManager>(
0, (cache != nullptr) ? *cache : std::shared_ptr<Cache>());
write_buffer_manager = wbm;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeForSmallDb(
std::shared_ptr<Cache>* cache) {
write_buffer_size = 2 << 20;
target_file_size_base = 2 * 1048576;
max_bytes_for_level_base = 10 * 1048576;
snap_refresh_nanos = 0;
soft_pending_compaction_bytes_limit = 256 * 1048576;
hard_pending_compaction_bytes_limit = 1073741824ul;
BlockBasedTableOptions table_options;
table_options.block_cache =
(cache != nullptr) ? *cache : std::shared_ptr<Cache>();
table_options.cache_index_and_filter_blocks = true;
// Two level iterator to avoid LRU cache imbalance
table_options.index_type =
BlockBasedTableOptions::IndexType::kTwoLevelIndexSearch;
table_factory.reset(new BlockBasedTableFactory(table_options));
return this;
}
#ifndef ROCKSDB_LITE
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeForPointLookup(
uint64_t block_cache_size_mb) {
BlockBasedTableOptions block_based_options;
block_based_options.data_block_index_type =
BlockBasedTableOptions::kDataBlockBinaryAndHash;
block_based_options.data_block_hash_table_util_ratio = 0.75;
block_based_options.filter_policy.reset(NewBloomFilterPolicy(10));
block_based_options.block_cache =
NewLRUCache(static_cast<size_t>(block_cache_size_mb * 1024 * 1024));
table_factory.reset(new BlockBasedTableFactory(block_based_options));
memtable_prefix_bloom_size_ratio = 0.02;
memtable_whole_key_filtering = true;
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeLevelStyleCompaction(
uint64_t memtable_memory_budget) {
write_buffer_size = static_cast<size_t>(memtable_memory_budget / 4);
// merge two memtables when flushing to L0
min_write_buffer_number_to_merge = 2;
// this means we'll use 50% extra memory in the worst case, but will reduce
// write stalls.
max_write_buffer_number = 6;
// start flushing L0->L1 as soon as possible. each file on level0 is
// (memtable_memory_budget / 2). This will flush level 0 when it's bigger than
// memtable_memory_budget.
level0_file_num_compaction_trigger = 2;
// doesn't really matter much, but we don't want to create too many files
target_file_size_base = memtable_memory_budget / 8;
// make Level1 size equal to Level0 size, so that L0->L1 compactions are fast
max_bytes_for_level_base = memtable_memory_budget;
// level style compaction
compaction_style = kCompactionStyleLevel;
// only compress levels >= 2
compression_per_level.resize(num_levels);
for (int i = 0; i < num_levels; ++i) {
if (i < 2) {
compression_per_level[i] = kNoCompression;
} else {
compression_per_level[i] =
LZ4_Supported()
? kLZ4Compression
: (Snappy_Supported() ? kSnappyCompression : kNoCompression);
}
}
return this;
}
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeUniversalStyleCompaction(
uint64_t memtable_memory_budget) {
write_buffer_size = static_cast<size_t>(memtable_memory_budget / 4);
// merge two memtables when flushing to L0
min_write_buffer_number_to_merge = 2;
// this means we'll use 50% extra memory in the worst case, but will reduce
// write stalls.
max_write_buffer_number = 6;
// universal style compaction
compaction_style = kCompactionStyleUniversal;
compaction_options_universal.compression_size_percent = 80;
return this;
}
DBOptions* DBOptions::IncreaseParallelism(int total_threads) {
max_background_jobs = total_threads;
env->SetBackgroundThreads(total_threads, Env::LOW);
env->SetBackgroundThreads(1, Env::HIGH);
return this;
}
#endif // !ROCKSDB_LITE
ReadOptions::ReadOptions()
: snapshot(nullptr),
iterate_lower_bound(nullptr),
iterate_upper_bound(nullptr),
readahead_size(0),
max_skippable_internal_keys(0),
read_tier(kReadAllTier),
verify_checksums(true),
fill_cache(true),
tailing(false),
managed(false),
total_order_seek(false),
prefix_same_as_start(false),
pin_data(false),
background_purge_on_iterator_cleanup(false),
ignore_range_deletions(false),
iter_start_seqnum(0) {}
ReadOptions::ReadOptions(bool cksum, bool cache)
: snapshot(nullptr),
iterate_lower_bound(nullptr),
iterate_upper_bound(nullptr),
readahead_size(0),
max_skippable_internal_keys(0),
read_tier(kReadAllTier),
verify_checksums(cksum),
fill_cache(cache),
tailing(false),
managed(false),
total_order_seek(false),
prefix_same_as_start(false),
pin_data(false),
background_purge_on_iterator_cleanup(false),
ignore_range_deletions(false),
iter_start_seqnum(0) {}
} // namespace rocksdb