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rocksdb/tools/block_cache_trace_analyzer.h

189 lines
6.7 KiB

// 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 <map>
#include <vector>
#include "rocksdb/env.h"
#include "rocksdb/utilities/sim_cache.h"
#include "trace_replay/block_cache_tracer.h"
namespace rocksdb {
class BlockCacheTraceAnalyzer;
// A cache configuration provided by user.
struct CacheConfiguration {
std::string cache_name; // LRU.
uint32_t num_shard_bits;
std::vector<uint64_t>
cache_capacities; // simulate cache capacities in bytes.
};
// A block cache simulator that reports miss ratio curves given a set of cache
// configurations.
class BlockCacheTraceSimulator {
public:
// warmup_seconds: The number of seconds to warmup simulated caches. The
// hit/miss counters are reset after the warmup completes.
BlockCacheTraceSimulator(
uint64_t warmup_seconds, uint32_t downsample_ratio,
const std::vector<CacheConfiguration>& cache_configurations);
~BlockCacheTraceSimulator() = default;
// No copy and move.
BlockCacheTraceSimulator(const BlockCacheTraceSimulator&) = delete;
BlockCacheTraceSimulator& operator=(const BlockCacheTraceSimulator&) = delete;
BlockCacheTraceSimulator(BlockCacheTraceSimulator&&) = delete;
BlockCacheTraceSimulator& operator=(BlockCacheTraceSimulator&&) = delete;
void Access(const BlockCacheTraceRecord& access);
const std::vector<std::shared_ptr<SimCache>>& sim_caches() const {
return sim_caches_;
}
const std::vector<CacheConfiguration>& cache_configurations() const {
return cache_configurations_;
}
private:
const uint64_t warmup_seconds_;
const uint32_t downsample_ratio_;
const std::vector<CacheConfiguration> cache_configurations_;
bool warmup_complete_ = false;
std::vector<std::shared_ptr<SimCache>> sim_caches_;
uint64_t trace_start_time_ = 0;
};
// Statistics of a block.
struct BlockAccessInfo {
uint64_t num_accesses = 0;
uint64_t block_size = 0;
uint64_t first_access_time = 0;
uint64_t last_access_time = 0;
uint64_t num_keys = 0;
std::map<std::string, uint64_t>
key_num_access_map; // for keys exist in this block.
std::map<std::string, uint64_t>
non_exist_key_num_access_map; // for keys do not exist in this block.
uint64_t num_referenced_key_exist_in_block = 0;
std::map<BlockCacheLookupCaller, uint64_t> caller_num_access_map;
void AddAccess(const BlockCacheTraceRecord& access) {
if (first_access_time == 0) {
first_access_time = access.access_timestamp;
}
last_access_time = access.access_timestamp;
block_size = access.block_size;
caller_num_access_map[access.caller]++;
num_accesses++;
if (BlockCacheTraceHelper::ShouldTraceReferencedKey(access.block_type,
access.caller)) {
num_keys = access.num_keys_in_block;
if (access.referenced_key_exist_in_block == Boolean::kTrue) {
key_num_access_map[access.referenced_key]++;
num_referenced_key_exist_in_block++;
} else {
non_exist_key_num_access_map[access.referenced_key]++;
}
}
}
};
// Aggregates stats of a block given a block type.
struct BlockTypeAccessInfoAggregate {
std::map<std::string, BlockAccessInfo> block_access_info_map;
};
// Aggregates BlockTypeAggregate given a SST file.
struct SSTFileAccessInfoAggregate {
uint32_t level;
std::map<TraceType, BlockTypeAccessInfoAggregate> block_type_aggregates_map;
};
// Aggregates SSTFileAggregate given a column family.
struct ColumnFamilyAccessInfoAggregate {
std::map<uint64_t, SSTFileAccessInfoAggregate> fd_aggregates_map;
};
class BlockCacheTraceAnalyzer {
public:
BlockCacheTraceAnalyzer(
const std::string& trace_file_path,
const std::string& output_miss_ratio_curve_path,
std::unique_ptr<BlockCacheTraceSimulator>&& cache_simulator);
~BlockCacheTraceAnalyzer() = default;
// No copy and move.
BlockCacheTraceAnalyzer(const BlockCacheTraceAnalyzer&) = delete;
BlockCacheTraceAnalyzer& operator=(const BlockCacheTraceAnalyzer&) = delete;
BlockCacheTraceAnalyzer(BlockCacheTraceAnalyzer&&) = delete;
BlockCacheTraceAnalyzer& operator=(BlockCacheTraceAnalyzer&&) = delete;
// Read all access records in the given trace_file, maintains the stats of
// a block, and aggregates the information by block type, sst file, and column
// family. Subsequently, the caller may call Print* functions to print
// statistics.
Status Analyze();
// Print a summary of statistics of the trace, e.g.,
// Number of files: 2 Number of blocks: 50 Number of accesses: 50
// Number of Index blocks: 10
// Number of Filter blocks: 10
// Number of Data blocks: 10
// Number of UncompressionDict blocks: 10
// Number of RangeDeletion blocks: 10
// ***************************************************************
// Caller Get: Number of accesses 10
// Caller Get: Number of accesses per level break down
// Level 0: Number of accesses: 10
// Caller Get: Number of accesses per block type break down
// Block Type Index: Number of accesses: 2
// Block Type Filter: Number of accesses: 2
// Block Type Data: Number of accesses: 2
// Block Type UncompressionDict: Number of accesses: 2
// Block Type RangeDeletion: Number of accesses: 2
void PrintStatsSummary() const;
// Print block size distribution and the distribution break down by block type
// and column family.
void PrintBlockSizeStats() const;
// Print access count distribution and the distribution break down by block
// type and column family.
void PrintAccessCountStats() const;
// Print data block accesses by user Get and Multi-Get.
// It prints out 1) A histogram on the percentage of keys accessed in a data
// block break down by if a referenced key exists in the data block andthe
// histogram break down by column family. 2) A histogram on the percentage of
// accesses on keys exist in a data block and its break down by column family.
void PrintDataBlockAccessStats() const;
void PrintMissRatioCurves() const;
const std::map<std::string, ColumnFamilyAccessInfoAggregate>&
TEST_cf_aggregates_map() const {
return cf_aggregates_map_;
}
private:
void RecordAccess(const BlockCacheTraceRecord& access);
rocksdb::Env* env_;
const std::string trace_file_path_;
const std::string output_miss_ratio_curve_path_;
BlockCacheTraceHeader header_;
std::unique_ptr<BlockCacheTraceSimulator> cache_simulator_;
std::map<std::string, ColumnFamilyAccessInfoAggregate> cf_aggregates_map_;
};
int block_cache_trace_analyzer_tool(int argc, char** argv);
} // namespace rocksdb