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f241d082b6
Summary: ### **Summary:** When both LRU Cache and CompressedSecondaryCache are configured together, there possibly are some data blocks double cached. **Changes include:** 1. Update IS_PROMOTED to IS_IN_SECONDARY_CACHE to prevent confusions. 2. This PR updates SecondaryCacheResultHandle and use IsErasedFromSecondaryCache to determine whether the handle is erased in the secondary cache. Then, the caller can determine whether to SetIsInSecondaryCache(). 3. Rename LRUSecondaryCache to CompressedSecondaryCache. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9747 Test Plan: **Test Scripts:** 1. Populate a DB. The on disk footprint is 482 MB. The data is set to be 50% compressible, so the total decompressed size is expected to be 964 MB. ./db_bench --benchmarks=fillrandom --num=10000000 -db=/db_bench_1 2. overwrite it to a stable state: ./db_bench --benchmarks=overwrite,stats --num=10000000 -use_existing_db -duration=10 --benchmark_write_rate_limit=2000000 -db=/db_bench_1 4. Run read tests with diffeernt cache setting: T1: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=520000000 --statistics -db=/db_bench_1 T2: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=320000000 -compressed_secondary_cache_size=400000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 T3: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=520000000 -compressed_secondary_cache_size=400000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 T4: ./db_bench --benchmarks=seekrandom,stats --threads=16 --num=10000000 -use_existing_db -duration=120 --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=20000000 -compressed_secondary_cache_size=500000000 --statistics -use_compressed_secondary_cache -db=/db_bench_1 **Before this PR** | Cache Size | Compressed Secondary Cache Size | Cache Hit Rate | |------------|-------------------------------------|----------------| |520 MB | 0 MB | 85.5% | |320 MB | 400 MB | 96.2% | |520 MB | 400 MB | 98.3% | |20 MB | 500 MB | 98.8% | **Before this PR** | Cache Size | Compressed Secondary Cache Size | Cache Hit Rate | |------------|-------------------------------------|----------------| |520 MB | 0 MB | 85.5% | |320 MB | 400 MB | 99.9% | |520 MB | 400 MB | 99.9% | |20 MB | 500 MB | 99.2% | Reviewed By: anand1976 Differential Revision: D35117499 Pulled By: gitbw95 fbshipit-source-id: ea2657749fc13efebe91a8a1b56bc61d6a224a12
87 lines
2.8 KiB
C++
87 lines
2.8 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under both the GPLv2 (found in the
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// COPYING file in the root directory) and Apache 2.0 License
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// (found in the LICENSE.Apache file in the root directory).
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#pragma once
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#include <memory>
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#include "cache/lru_cache.h"
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#include "memory/memory_allocator.h"
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#include "rocksdb/secondary_cache.h"
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#include "rocksdb/slice.h"
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#include "rocksdb/status.h"
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#include "util/compression.h"
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namespace ROCKSDB_NAMESPACE {
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class CompressedSecondaryCacheResultHandle : public SecondaryCacheResultHandle {
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public:
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CompressedSecondaryCacheResultHandle(void* value, size_t size)
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: value_(value), size_(size) {}
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virtual ~CompressedSecondaryCacheResultHandle() override = default;
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CompressedSecondaryCacheResultHandle(
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const CompressedSecondaryCacheResultHandle&) = delete;
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CompressedSecondaryCacheResultHandle& operator=(
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const CompressedSecondaryCacheResultHandle&) = delete;
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bool IsReady() override { return true; }
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void Wait() override {}
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void* Value() override { return value_; }
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size_t Size() override { return size_; }
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private:
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void* value_;
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size_t size_;
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};
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// The CompressedSecondaryCache is a concrete implementation of
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// rocksdb::SecondaryCache.
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//
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// Users can also cast a pointer to it and call methods on
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// it directly, especially custom methods that may be added
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// in the future. For example -
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// std::unique_ptr<rocksdb::SecondaryCache> cache =
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// NewCompressedSecondaryCache(opts);
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// static_cast<CompressedSecondaryCache*>(cache.get())->Erase(key);
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class CompressedSecondaryCache : public SecondaryCache {
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public:
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CompressedSecondaryCache(
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size_t capacity, int num_shard_bits, bool strict_capacity_limit,
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double high_pri_pool_ratio,
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std::shared_ptr<MemoryAllocator> memory_allocator = nullptr,
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bool use_adaptive_mutex = kDefaultToAdaptiveMutex,
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CacheMetadataChargePolicy metadata_charge_policy =
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kDontChargeCacheMetadata,
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CompressionType compression_type = CompressionType::kLZ4Compression,
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uint32_t compress_format_version = 2);
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virtual ~CompressedSecondaryCache() override;
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const char* Name() const override { return "CompressedSecondaryCache"; }
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Status Insert(const Slice& key, void* value,
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const Cache::CacheItemHelper* helper) override;
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std::unique_ptr<SecondaryCacheResultHandle> Lookup(
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const Slice& key, const Cache::CreateCallback& create_cb, bool /*wait*/,
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bool& is_in_sec_cache) override;
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void Erase(const Slice& key) override;
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void WaitAll(std::vector<SecondaryCacheResultHandle*> /*handles*/) override {}
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std::string GetPrintableOptions() const override;
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private:
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std::shared_ptr<Cache> cache_;
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CompressedSecondaryCacheOptions cache_options_;
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};
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} // namespace ROCKSDB_NAMESPACE
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