Revision 80de9004649753d87fa1b2d41127b1401a4c0065 authored by Levi Tamasi on 13 December 2019, 20:45:49 UTC, committed by Levi Tamasi on 17 December 2019, 15:52:22 UTC
Summary: We have observed an increase in CPU load caused by frequent calls to `ColumnFamilyData::InstallSuperVersion` from `DBImpl::TrimMemtableHistory` when using `max_write_buffer_size_to_maintain` to limit the amount of memtable history maintained for transaction conflict checking. As it turns out, this is caused by the code creating and installing a new `SuperVersion` even if no memtables were actually trimmed. The patch adds a check to avoid this. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6169 Test Plan: Compared `perf` output for ``` ./db_bench -benchmarks=randomtransaction -optimistic_transaction_db=1 -statistics -stats_interval_seconds=1 -duration=90 -num=500000 --max_write_buffer_size_to_maintain=16000000 --transaction_set_snapshot=1 --threads=32 ``` before and after the change. With the fix, the call chain `rocksdb::DBImpl::TrimMemtableHistory` -> `rocksdb::ColumnFamilyData::InstallSuperVersion` -> `rocksdb::ThreadLocalPtr::StaticMeta::Scrape` no longer registers in the `perf` report. Differential Revision: D19031509 Pulled By: ltamasi fbshipit-source-id: 02686fce594e5b50eba0710e4b28a9b808c8aa20
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options_sanity_check.h
// 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).
#pragma once
#include <string>
#include <unordered_map>
#ifndef ROCKSDB_LITE
namespace rocksdb {
// This enum defines the RocksDB options sanity level.
enum OptionsSanityCheckLevel : unsigned char {
// Performs no sanity check at all.
kSanityLevelNone = 0x00,
// Performs minimum check to ensure the RocksDB instance can be
// opened without corrupting / mis-interpreting the data.
kSanityLevelLooselyCompatible = 0x01,
// Perform exact match sanity check.
kSanityLevelExactMatch = 0xFF,
};
// The sanity check level for DB options
static const std::unordered_map<std::string, OptionsSanityCheckLevel>
sanity_level_db_options {};
// The sanity check level for column-family options
static const std::unordered_map<std::string, OptionsSanityCheckLevel>
sanity_level_cf_options = {
{"comparator", kSanityLevelLooselyCompatible},
{"table_factory", kSanityLevelLooselyCompatible},
{"merge_operator", kSanityLevelLooselyCompatible}};
// The sanity check level for block-based table options
static const std::unordered_map<std::string, OptionsSanityCheckLevel>
sanity_level_bbt_options {};
OptionsSanityCheckLevel DBOptionSanityCheckLevel(
const std::string& options_name);
OptionsSanityCheckLevel CFOptionSanityCheckLevel(
const std::string& options_name);
OptionsSanityCheckLevel BBTOptionSanityCheckLevel(
const std::string& options_name);
} // namespace rocksdb
#endif // !ROCKSDB_LITE
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