rocksdb/util/options.cc
Igor Canadi 62ad0a9b19 Deprecating skip_log_error_on_recovery
Summary:
Since https://reviews.facebook.net/D16119, we ignore partial tailing writes. Because of that, we no longer need skip_log_error_on_recovery.

The documentation says "Skip log corruption error on recovery (If client is ok with losing most recent changes)", while the option actually ignores any corruption of the WAL (not only just the most recent changes). This is very dangerous and can lead to DB inconsistencies. This was originally set up to ignore partial tailing writes, which we now do automatically (after D16119). I have digged up old task t2416297 which confirms my findings.

Test Plan: There was actually no tests that verified correct behavior of skip_log_error_on_recovery.

Reviewers: yhchiang, rven, dhruba, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D30603
2015-01-05 13:35:56 -08:00

589 lines
26 KiB
C++

// Copyright (c) 2013, 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.
//
// 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"
#include "rocksdb/immutable_options.h"
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <limits>
#include "db/writebuffer.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/table.h"
#include "rocksdb/table_properties.h"
#include "table/block_based_table_factory.h"
#include "util/statistics.h"
namespace rocksdb {
ImmutableCFOptions::ImmutableCFOptions(const Options& options)
: compaction_style(options.compaction_style),
compaction_options_universal(options.compaction_options_universal),
compaction_options_fifo(options.compaction_options_fifo),
prefix_extractor(options.prefix_extractor.get()),
comparator(options.comparator),
merge_operator(options.merge_operator.get()),
compaction_filter(options.compaction_filter),
compaction_filter_factory(options.compaction_filter_factory.get()),
compaction_filter_factory_v2(options.compaction_filter_factory_v2.get()),
inplace_update_support(options.inplace_update_support),
inplace_callback(options.inplace_callback),
info_log(options.info_log.get()),
statistics(options.statistics.get()),
env(options.env),
allow_mmap_reads(options.allow_mmap_reads),
allow_mmap_writes(options.allow_mmap_writes),
db_paths(options.db_paths),
memtable_factory(options.memtable_factory.get()),
table_factory(options.table_factory.get()),
table_properties_collector_factories(
options.table_properties_collector_factories),
advise_random_on_open(options.advise_random_on_open),
bloom_locality(options.bloom_locality),
purge_redundant_kvs_while_flush(options.purge_redundant_kvs_while_flush),
min_partial_merge_operands(options.min_partial_merge_operands),
disable_data_sync(options.disableDataSync),
use_fsync(options.use_fsync),
compression(options.compression),
compression_per_level(options.compression_per_level),
compression_opts(options.compression_opts),
access_hint_on_compaction_start(options.access_hint_on_compaction_start),
num_levels(options.num_levels)
#ifndef ROCKSDB_LITE
, listeners(options.listeners) {}
#else // ROCKSDB_LITE
{}
#endif // ROCKSDB_LITE
ColumnFamilyOptions::ColumnFamilyOptions()
: comparator(BytewiseComparator()),
merge_operator(nullptr),
compaction_filter(nullptr),
compaction_filter_factory(std::shared_ptr<CompactionFilterFactory>(
new DefaultCompactionFilterFactory())),
compaction_filter_factory_v2(new DefaultCompactionFilterFactoryV2()),
write_buffer_size(4 << 20),
max_write_buffer_number(2),
min_write_buffer_number_to_merge(1),
compression(kSnappyCompression),
prefix_extractor(nullptr),
num_levels(7),
level0_file_num_compaction_trigger(4),
level0_slowdown_writes_trigger(20),
level0_stop_writes_trigger(24),
max_mem_compaction_level(2),
target_file_size_base(2 * 1048576),
target_file_size_multiplier(1),
max_bytes_for_level_base(10 * 1048576),
max_bytes_for_level_multiplier(10),
max_bytes_for_level_multiplier_additional(num_levels, 1),
expanded_compaction_factor(25),
source_compaction_factor(1),
max_grandparent_overlap_factor(10),
soft_rate_limit(0.0),
hard_rate_limit(0.0),
rate_limit_delay_max_milliseconds(1000),
arena_block_size(0),
disable_auto_compactions(false),
purge_redundant_kvs_while_flush(true),
compaction_style(kCompactionStyleLevel),
verify_checksums_in_compaction(true),
filter_deletes(false),
max_sequential_skip_in_iterations(8),
memtable_factory(std::shared_ptr<SkipListFactory>(new SkipListFactory)),
table_factory(
std::shared_ptr<TableFactory>(new BlockBasedTableFactory())),
inplace_update_support(false),
inplace_update_num_locks(10000),
inplace_callback(nullptr),
memtable_prefix_bloom_bits(0),
memtable_prefix_bloom_probes(6),
memtable_prefix_bloom_huge_page_tlb_size(0),
bloom_locality(0),
max_successive_merges(0),
min_partial_merge_operands(2)
#ifndef ROCKSDB_LITE
, listeners() {
#else // ROCKSDB_LITE
{
#endif // ROCKSDB_LITE
assert(memtable_factory.get() != nullptr);
}
ColumnFamilyOptions::ColumnFamilyOptions(const Options& options)
: comparator(options.comparator),
merge_operator(options.merge_operator),
compaction_filter(options.compaction_filter),
compaction_filter_factory(options.compaction_filter_factory),
compaction_filter_factory_v2(options.compaction_filter_factory_v2),
write_buffer_size(options.write_buffer_size),
max_write_buffer_number(options.max_write_buffer_number),
min_write_buffer_number_to_merge(
options.min_write_buffer_number_to_merge),
compression(options.compression),
compression_per_level(options.compression_per_level),
compression_opts(options.compression_opts),
prefix_extractor(options.prefix_extractor),
num_levels(options.num_levels),
level0_file_num_compaction_trigger(
options.level0_file_num_compaction_trigger),
level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
level0_stop_writes_trigger(options.level0_stop_writes_trigger),
max_mem_compaction_level(options.max_mem_compaction_level),
target_file_size_base(options.target_file_size_base),
target_file_size_multiplier(options.target_file_size_multiplier),
max_bytes_for_level_base(options.max_bytes_for_level_base),
max_bytes_for_level_multiplier(options.max_bytes_for_level_multiplier),
max_bytes_for_level_multiplier_additional(
options.max_bytes_for_level_multiplier_additional),
expanded_compaction_factor(options.expanded_compaction_factor),
source_compaction_factor(options.source_compaction_factor),
max_grandparent_overlap_factor(options.max_grandparent_overlap_factor),
soft_rate_limit(options.soft_rate_limit),
hard_rate_limit(options.hard_rate_limit),
rate_limit_delay_max_milliseconds(
options.rate_limit_delay_max_milliseconds),
arena_block_size(options.arena_block_size),
disable_auto_compactions(options.disable_auto_compactions),
purge_redundant_kvs_while_flush(options.purge_redundant_kvs_while_flush),
compaction_style(options.compaction_style),
verify_checksums_in_compaction(options.verify_checksums_in_compaction),
compaction_options_universal(options.compaction_options_universal),
compaction_options_fifo(options.compaction_options_fifo),
filter_deletes(options.filter_deletes),
max_sequential_skip_in_iterations(
options.max_sequential_skip_in_iterations),
memtable_factory(options.memtable_factory),
table_factory(options.table_factory),
table_properties_collector_factories(
options.table_properties_collector_factories),
inplace_update_support(options.inplace_update_support),
inplace_update_num_locks(options.inplace_update_num_locks),
inplace_callback(options.inplace_callback),
memtable_prefix_bloom_bits(options.memtable_prefix_bloom_bits),
memtable_prefix_bloom_probes(options.memtable_prefix_bloom_probes),
memtable_prefix_bloom_huge_page_tlb_size(
options.memtable_prefix_bloom_huge_page_tlb_size),
bloom_locality(options.bloom_locality),
max_successive_merges(options.max_successive_merges),
min_partial_merge_operands(options.min_partial_merge_operands)
#ifndef ROCKSDB_LITE
, listeners(options.listeners) {
#else // ROCKSDB_LITE
{
#endif // ROCKSDB_LITE
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);
}
}
DBOptions::DBOptions()
: create_if_missing(false),
create_missing_column_families(false),
error_if_exists(false),
paranoid_checks(true),
env(Env::Default()),
rate_limiter(nullptr),
info_log(nullptr),
info_log_level(INFO_LEVEL),
max_open_files(5000),
max_total_wal_size(0),
statistics(nullptr),
disableDataSync(false),
use_fsync(false),
db_log_dir(""),
wal_dir(""),
delete_obsolete_files_period_micros(6 * 60 * 60 * 1000000UL),
max_background_compactions(1),
max_background_flushes(1),
max_log_file_size(0),
log_file_time_to_roll(0),
keep_log_file_num(1000),
max_manifest_file_size(std::numeric_limits<uint64_t>::max()),
table_cache_numshardbits(4),
table_cache_remove_scan_count_limit(16),
WAL_ttl_seconds(0),
WAL_size_limit_MB(0),
manifest_preallocation_size(4 * 1024 * 1024),
allow_os_buffer(true),
allow_mmap_reads(false),
allow_mmap_writes(false),
is_fd_close_on_exec(true),
skip_log_error_on_recovery(false),
stats_dump_period_sec(3600),
advise_random_on_open(true),
db_write_buffer_size(0),
access_hint_on_compaction_start(NORMAL),
use_adaptive_mutex(false),
bytes_per_sync(0),
enable_thread_tracking(false) {}
DBOptions::DBOptions(const Options& options)
: create_if_missing(options.create_if_missing),
create_missing_column_families(options.create_missing_column_families),
error_if_exists(options.error_if_exists),
paranoid_checks(options.paranoid_checks),
env(options.env),
rate_limiter(options.rate_limiter),
info_log(options.info_log),
info_log_level(options.info_log_level),
max_open_files(options.max_open_files),
max_total_wal_size(options.max_total_wal_size),
statistics(options.statistics),
disableDataSync(options.disableDataSync),
use_fsync(options.use_fsync),
db_paths(options.db_paths),
db_log_dir(options.db_log_dir),
wal_dir(options.wal_dir),
delete_obsolete_files_period_micros(
options.delete_obsolete_files_period_micros),
max_background_compactions(options.max_background_compactions),
max_background_flushes(options.max_background_flushes),
max_log_file_size(options.max_log_file_size),
log_file_time_to_roll(options.log_file_time_to_roll),
keep_log_file_num(options.keep_log_file_num),
max_manifest_file_size(options.max_manifest_file_size),
table_cache_numshardbits(options.table_cache_numshardbits),
table_cache_remove_scan_count_limit(
options.table_cache_remove_scan_count_limit),
WAL_ttl_seconds(options.WAL_ttl_seconds),
WAL_size_limit_MB(options.WAL_size_limit_MB),
manifest_preallocation_size(options.manifest_preallocation_size),
allow_os_buffer(options.allow_os_buffer),
allow_mmap_reads(options.allow_mmap_reads),
allow_mmap_writes(options.allow_mmap_writes),
is_fd_close_on_exec(options.is_fd_close_on_exec),
skip_log_error_on_recovery(options.skip_log_error_on_recovery),
stats_dump_period_sec(options.stats_dump_period_sec),
advise_random_on_open(options.advise_random_on_open),
db_write_buffer_size(options.db_write_buffer_size),
access_hint_on_compaction_start(options.access_hint_on_compaction_start),
use_adaptive_mutex(options.use_adaptive_mutex),
bytes_per_sync(options.bytes_per_sync),
enable_thread_tracking(options.enable_thread_tracking) {}
static const char* const access_hints[] = {
"NONE", "NORMAL", "SEQUENTIAL", "WILLNEED"
};
void DBOptions::Dump(Logger* log) const {
Log(log," Options.error_if_exists: %d", error_if_exists);
Log(log," Options.create_if_missing: %d", create_if_missing);
Log(log," Options.paranoid_checks: %d", paranoid_checks);
Log(log," Options.env: %p", env);
Log(log," Options.info_log: %p", info_log.get());
Log(log," Options.max_open_files: %d", max_open_files);
Log(log," Options.max_total_wal_size: %" PRIu64, max_total_wal_size);
Log(log, " Options.disableDataSync: %d", disableDataSync);
Log(log, " Options.use_fsync: %d", use_fsync);
Log(log, " Options.max_log_file_size: %zu", max_log_file_size);
Log(log, "Options.max_manifest_file_size: %" PRIu64,
max_manifest_file_size);
Log(log, " Options.log_file_time_to_roll: %zu", log_file_time_to_roll);
Log(log, " Options.keep_log_file_num: %zu", keep_log_file_num);
Log(log, " Options.allow_os_buffer: %d", allow_os_buffer);
Log(log, " Options.allow_mmap_reads: %d", allow_mmap_reads);
Log(log, " Options.allow_mmap_writes: %d", allow_mmap_writes);
Log(log, " Options.create_missing_column_families: %d",
create_missing_column_families);
Log(log, " Options.db_log_dir: %s",
db_log_dir.c_str());
Log(log, " Options.wal_dir: %s",
wal_dir.c_str());
Log(log, " Options.table_cache_numshardbits: %d",
table_cache_numshardbits);
Log(log, " Options.table_cache_remove_scan_count_limit: %d",
table_cache_remove_scan_count_limit);
Log(log, " Options.delete_obsolete_files_period_micros: %" PRIu64,
delete_obsolete_files_period_micros);
Log(log, " Options.max_background_compactions: %d",
max_background_compactions);
Log(log, " Options.max_background_flushes: %d",
max_background_flushes);
Log(log, " Options.WAL_ttl_seconds: %" PRIu64,
WAL_ttl_seconds);
Log(log, " Options.WAL_size_limit_MB: %" PRIu64,
WAL_size_limit_MB);
Log(log, " Options.manifest_preallocation_size: %zu",
manifest_preallocation_size);
Log(log, " Options.allow_os_buffer: %d",
allow_os_buffer);
Log(log, " Options.allow_mmap_reads: %d",
allow_mmap_reads);
Log(log, " Options.allow_mmap_writes: %d",
allow_mmap_writes);
Log(log, " Options.is_fd_close_on_exec: %d",
is_fd_close_on_exec);
Log(log, " Options.stats_dump_period_sec: %u",
stats_dump_period_sec);
Log(log, " Options.advise_random_on_open: %d",
advise_random_on_open);
Log(log, " Options.db_write_buffer_size: %zd",
db_write_buffer_size);
Log(log, " Options.access_hint_on_compaction_start: %s",
access_hints[access_hint_on_compaction_start]);
Log(log, " Options.use_adaptive_mutex: %d",
use_adaptive_mutex);
Log(log, " Options.rate_limiter: %p",
rate_limiter.get());
Log(log, " Options.bytes_per_sync: %" PRIu64,
bytes_per_sync);
Log(log, " enable_thread_tracking: %d",
enable_thread_tracking);
} // DBOptions::Dump
void ColumnFamilyOptions::Dump(Logger* log) const {
Log(log, " Options.comparator: %s", comparator->Name());
Log(log, " Options.merge_operator: %s",
merge_operator ? merge_operator->Name() : "None");
Log(log, " Options.compaction_filter: %s",
compaction_filter ? compaction_filter->Name() : "None");
Log(log, " Options.compaction_filter_factory: %s",
compaction_filter_factory->Name());
Log(log, " Options.compaction_filter_factory_v2: %s",
compaction_filter_factory_v2->Name());
Log(log, " Options.memtable_factory: %s", memtable_factory->Name());
Log(log, " Options.table_factory: %s", table_factory->Name());
Log(log, " table_factory options: %s",
table_factory->GetPrintableTableOptions().c_str());
Log(log, " Options.write_buffer_size: %zd", write_buffer_size);
Log(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++) {
Log(log," Options.compression[%d]: %d",
i, compression_per_level[i]);
}
} else {
Log(log," Options.compression: %d", compression);
}
Log(log," Options.prefix_extractor: %s",
prefix_extractor == nullptr ? "nullptr" : prefix_extractor->Name());
Log(log," Options.num_levels: %d", num_levels);
Log(log," Options.min_write_buffer_number_to_merge: %d",
min_write_buffer_number_to_merge);
Log(log," Options.purge_redundant_kvs_while_flush: %d",
purge_redundant_kvs_while_flush);
Log(log," Options.compression_opts.window_bits: %d",
compression_opts.window_bits);
Log(log," Options.compression_opts.level: %d",
compression_opts.level);
Log(log," Options.compression_opts.strategy: %d",
compression_opts.strategy);
Log(log," Options.level0_file_num_compaction_trigger: %d",
level0_file_num_compaction_trigger);
Log(log," Options.level0_slowdown_writes_trigger: %d",
level0_slowdown_writes_trigger);
Log(log," Options.level0_stop_writes_trigger: %d",
level0_stop_writes_trigger);
Log(log," Options.max_mem_compaction_level: %d",
max_mem_compaction_level);
Log(log," Options.target_file_size_base: %" PRIu64,
target_file_size_base);
Log(log," Options.target_file_size_multiplier: %d",
target_file_size_multiplier);
Log(log," Options.max_bytes_for_level_base: %" PRIu64,
max_bytes_for_level_base);
Log(log," Options.max_bytes_for_level_multiplier: %d",
max_bytes_for_level_multiplier);
for (int i = 0; i < num_levels; i++) {
Log(log,"Options.max_bytes_for_level_multiplier_addtl[%d]: %d",
i, max_bytes_for_level_multiplier_additional[i]);
}
Log(log," Options.max_sequential_skip_in_iterations: %" PRIu64,
max_sequential_skip_in_iterations);
Log(log," Options.expanded_compaction_factor: %d",
expanded_compaction_factor);
Log(log," Options.source_compaction_factor: %d",
source_compaction_factor);
Log(log," Options.max_grandparent_overlap_factor: %d",
max_grandparent_overlap_factor);
Log(log," Options.arena_block_size: %zu",
arena_block_size);
Log(log," Options.soft_rate_limit: %.2f",
soft_rate_limit);
Log(log," Options.hard_rate_limit: %.2f",
hard_rate_limit);
Log(log," Options.rate_limit_delay_max_milliseconds: %u",
rate_limit_delay_max_milliseconds);
Log(log," Options.disable_auto_compactions: %d",
disable_auto_compactions);
Log(log," Options.purge_redundant_kvs_while_flush: %d",
purge_redundant_kvs_while_flush);
Log(log," Options.filter_deletes: %d",
filter_deletes);
Log(log, " Options.verify_checksums_in_compaction: %d",
verify_checksums_in_compaction);
Log(log," Options.compaction_style: %d",
compaction_style);
Log(log," Options.compaction_options_universal.size_ratio: %u",
compaction_options_universal.size_ratio);
Log(log,"Options.compaction_options_universal.min_merge_width: %u",
compaction_options_universal.min_merge_width);
Log(log,"Options.compaction_options_universal.max_merge_width: %u",
compaction_options_universal.max_merge_width);
Log(log,"Options.compaction_options_universal."
"max_size_amplification_percent: %u",
compaction_options_universal.max_size_amplification_percent);
Log(log,
"Options.compaction_options_universal.compression_size_percent: %d",
compaction_options_universal.compression_size_percent);
Log(log, "Options.compaction_options_fifo.max_table_files_size: %" PRIu64,
compaction_options_fifo.max_table_files_size);
std::string collector_names;
for (const auto& collector_factory : table_properties_collector_factories) {
collector_names.append(collector_factory->Name());
collector_names.append("; ");
}
Log(log, " Options.table_properties_collectors: %s",
collector_names.c_str());
Log(log, " Options.inplace_update_support: %d",
inplace_update_support);
Log(log, " Options.inplace_update_num_locks: %zd",
inplace_update_num_locks);
Log(log, " Options.min_partial_merge_operands: %u",
min_partial_merge_operands);
// TODO: easier config for bloom (maybe based on avg key/value size)
Log(log, " Options.memtable_prefix_bloom_bits: %d",
memtable_prefix_bloom_bits);
Log(log, " Options.memtable_prefix_bloom_probes: %d",
memtable_prefix_bloom_probes);
Log(log, " Options.memtable_prefix_bloom_huge_page_tlb_size: %zu",
memtable_prefix_bloom_huge_page_tlb_size);
Log(log, " Options.bloom_locality: %d",
bloom_locality);
Log(log, " Options.max_successive_merges: %zd",
max_successive_merges);
} // ColumnFamilyOptions::Dump
void Options::Dump(Logger* log) const {
DBOptions::Dump(log);
ColumnFamilyOptions::Dump(log);
} // Options::Dump
//
// 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);
// no auto compactions please. The application should issue a
// manual compaction after all data is loaded into L0.
disable_auto_compactions = true;
disableDataSync = true;
// A manual compaction run should pick all files in L0 in
// a single compaction run.
source_compaction_factor = (1<<30);
// 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;
// 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;
}
#ifndef ROCKSDB_LITE
// Optimization functions
ColumnFamilyOptions* ColumnFamilyOptions::OptimizeForPointLookup(
uint64_t block_cache_size_mb) {
prefix_extractor.reset(NewNoopTransform());
BlockBasedTableOptions block_based_options;
block_based_options.index_type = BlockBasedTableOptions::kHashSearch;
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_factory.reset(NewHashLinkListRepFactory());
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] = kSnappyCompression;
}
}
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_compactions = total_threads - 1;
max_background_flushes = 1;
env->SetBackgroundThreads(total_threads, Env::LOW);
env->SetBackgroundThreads(1, Env::HIGH);
return this;
}
#endif // ROCKSDB_LITE
} // namespace rocksdb