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Block cache analyzer: Add more stats (#5516) 

Summary:
This PR provides more command line options for block cache analyzer to better understand block cache access pattern.
-analyze_bottom_k_access_count_blocks
-analyze_top_k_access_count_blocks
-reuse_lifetime_labels
-reuse_lifetime_buckets
-analyze_callers
-access_count_buckets
-analyze_blocks_reuse_k_reuse_window
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5516

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16037440

Pulled By: HaoyuHuang

fbshipit-source-id: b9a4ac0d4712053fab910732077a4d4b91400bc8
This commit is contained in:
haoyuhuang 2019-07-12 16:52:15 -07:00 committed by Facebook Github Bot
parent 1a59b6e2a9
commit 3e9c5a3523
5 changed files with 1320 additions and 336 deletions
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1255
tools/block_cache_trace_analyzer.cc
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File diff suppressed because it is too large Load Diff

134
tools/block_cache_trace_analyzer.h
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@ -9,13 +9,13 @@
#include <set>
#include <vector>
#include "db/dbformat.h"
#include "rocksdb/env.h"
#include "rocksdb/utilities/sim_cache.h"
#include "trace_replay/block_cache_tracer.h"
#include "utilities/simulator_cache/cache_simulator.h"
namespace rocksdb {
// Statistics of a block.
struct BlockAccessInfo {
uint64_t num_accesses = 0;
@ -23,11 +23,12 @@ struct BlockAccessInfo {
uint64_t first_access_time = 0;
uint64_t last_access_time = 0;
uint64_t num_keys = 0;
std::map<std::string, uint64_t>
std::map<std::string, std::map<TableReaderCaller, uint64_t>>
key_num_access_map; // for keys exist in this block.
std::map<std::string, uint64_t>
std::map<std::string, std::map<TableReaderCaller, 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;
uint64_t referenced_data_size = 0;
std::map<TableReaderCaller, uint64_t> caller_num_access_map;
// caller:timestamp:number_of_accesses. The granularity of the timestamp is
// seconds.
@ -39,6 +40,12 @@ struct BlockAccessInfo {
std::map<uint64_t, uint64_t> reuse_distance_count;
void AddAccess(const BlockCacheTraceRecord& access) {
if (block_size != 0 && access.block_size != 0) {
assert(block_size == access.block_size);
}
if (num_keys != 0 && access.num_keys_in_block != 0) {
assert(num_keys == access.num_keys_in_block);
}
if (first_access_time == 0) {
first_access_time = access.access_timestamp;
}
@ -54,10 +61,18 @@ struct BlockAccessInfo {
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]++;
if (key_num_access_map.find(access.referenced_key) ==
key_num_access_map.end()) {
referenced_data_size += access.referenced_data_size;
}
key_num_access_map[access.referenced_key][access.caller]++;
num_referenced_key_exist_in_block++;
if (referenced_data_size > block_size && block_size != 0) {
ParsedInternalKey internal_key;
ParseInternalKey(access.referenced_key, &internal_key);
}
} else {
non_exist_key_num_access_map[access.referenced_key]++;
non_exist_key_num_access_map[access.referenced_key][access.caller]++;
}
}
}
@ -83,6 +98,7 @@ class BlockCacheTraceAnalyzer {
public:
BlockCacheTraceAnalyzer(
const std::string& trace_file_path, const std::string& output_dir,
bool compute_reuse_distance,
std::unique_ptr<BlockCacheTraceSimulator>&& cache_simulator);
~BlockCacheTraceAnalyzer() = default;
// No copy and move.
@ -122,7 +138,8 @@ class BlockCacheTraceAnalyzer {
// Print access count distribution and the distribution break down by block
// type and column family.
void PrintAccessCountStats() const;
void PrintAccessCountStats(bool user_access_only, uint32_t bottom_k,
uint32_t top_k) 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
@ -131,24 +148,93 @@ class BlockCacheTraceAnalyzer {
// accesses on keys exist in a data block and its break down by column family.
void PrintDataBlockAccessStats() const;
// Write the percentage of accesses break down by column family into a csv
// file saved in 'output_dir'.
//
// The file is named "percentage_of_accesses_summary". The file format is
// caller,cf_0,cf_1,...,cf_n where the cf_i is the column family name found in
// the trace.
void WritePercentAccessSummaryStats() const;
// Write the percentage of accesses for the given caller break down by column
// family, level, and block type into a csv file saved in 'output_dir'.
//
// It generates two files: 1) caller_level_percentage_of_accesses_summary and
// 2) caller_bt_percentage_of_accesses_summary which break down by the level
// and block type, respectively. The file format is
// level/bt,cf_0,cf_1,...,cf_n where cf_i is the column family name found in
// the trace.
void WriteDetailedPercentAccessSummaryStats(TableReaderCaller caller) const;
// Write the access count summary into a csv file saved in 'output_dir'.
// It groups blocks by their access count.
//
// It generates two files: 1) cf_access_count_summary and 2)
// bt_access_count_summary which break down the access count by column family
// and block type, respectively. The file format is
// cf/bt,bucket_0,bucket_1,...,bucket_N.
void WriteAccessCountSummaryStats(
const std::vector<uint64_t>& access_count_buckets,
bool user_access_only) const;
// Write miss ratio curves of simulated cache configurations into a csv file
// saved in 'output_dir'.
// named "mrc" saved in 'output_dir'.
//
// The file format is
// "cache_name,num_shard_bits,capacity,miss_ratio,total_accesses".
void WriteMissRatioCurves() const;
// Write the access timeline into a csv file saved in 'output_dir'.
void WriteAccessTimeline(const std::string& label) const;
//
// The file is named "label_access_timeline".The file format is
// "time,label_1_access_per_second,label_2_access_per_second,...,label_N_access_per_second"
// where N is the number of unique labels found in the trace.
void WriteAccessTimeline(const std::string& label, uint64_t time_unit,
bool user_access_only) const;
// Write the reuse distance into a csv file saved in 'output_dir'. Reuse
// distance is defined as the cumulated size of unique blocks read between two
// consective accesses on the same block.
//
// The file is named "label_reuse_distance". The file format is
// bucket,label_1,label_2,...,label_N.
void WriteReuseDistance(const std::string& label_str,
const std::set<uint64_t>& distance_buckets) const;
const std::vector<uint64_t>& distance_buckets) const;
// Write the reuse interval into a csv file saved in 'output_dir'. Reuse
// interval is defined as the time between two consecutive accesses on the
// same block..
// same block.
//
// The file is named "label_reuse_interval". The file format is
// bucket,label_1,label_2,...,label_N.
void WriteReuseInterval(const std::string& label_str,
const std::set<uint64_t>& time_buckets) const;
const std::vector<uint64_t>& time_buckets) const;
// Write the reuse lifetime into a csv file saved in 'output_dir'. Reuse
// lifetime is defined as the time interval between the first access of a
// block and its last access.
//
// The file is named "label_reuse_lifetime". The file format is
// bucket,label_1,label_2,...,label_N.
void WriteReuseLifetime(const std::string& label_str,
const std::vector<uint64_t>& time_buckets) const;
// Write the reuse timeline into a csv file saved in 'output_dir'.
//
// The file is named
// "block_type_user_access_only_reuse_window_reuse_timeline". The file format
// is start_time,0,1,...,N where N equals trace_duration / reuse_window.
void WriteBlockReuseTimeline(uint64_t reuse_window, bool user_access_only,
TraceType block_type) const;
// Write the Get spatical locality into csv files saved in 'output_dir'.
//
// It generates three csv files. label_percent_ref_keys,
// label_percent_accesses_on_ref_keys, and
// label_percent_data_size_on_ref_keys.
void WriteGetSpatialLocality(
const std::string& label_str,
const std::vector<uint64_t>& percent_buckets) const;
const std::map<std::string, ColumnFamilyAccessInfoAggregate>&
TEST_cf_aggregates_map() const {
@ -161,28 +247,48 @@ class BlockCacheTraceAnalyzer {
std::string BuildLabel(const std::set<std::string>& labels,
const std::string& cf_name, uint64_t fd,
uint32_t level, TraceType type,
TableReaderCaller caller,
const std::string& block_key) const;
TableReaderCaller caller, uint64_t block_key) const;
void ComputeReuseDistance(BlockAccessInfo* info) const;
void RecordAccess(const BlockCacheTraceRecord& access);
void UpdateReuseIntervalStats(
const std::string& label, const std::set<uint64_t>& time_buckets,
const std::string& label, const std::vector<uint64_t>& time_buckets,
const std::map<uint64_t, uint64_t> timeline,
std::map<std::string, std::map<uint64_t, uint64_t>>*
label_time_num_reuses,
uint64_t* total_num_reuses) const;
std::string OutputPercentAccessStats(
uint64_t total_accesses,
const std::map<std::string, uint64_t>& cf_access_count) const;
void WriteStatsToFile(
const std::string& label_str, const std::vector<uint64_t>& time_buckets,
const std::string& filename_suffix,
const std::map<std::string, std::map<uint64_t, uint64_t>>& label_data,
uint64_t ntotal) const;
void TraverseBlocks(
std::function<void(const std::string& /*cf_name*/, uint64_t /*fd*/,
uint32_t /*level*/, TraceType /*block_type*/,
const std::string& /*block_key*/,
uint64_t /*block_key_id*/,
const BlockAccessInfo& /*block_access_info*/)>
block_callback) const;
rocksdb::Env* env_;
const std::string trace_file_path_;
const std::string output_dir_;
const bool compute_reuse_distance_;
BlockCacheTraceHeader header_;
std::unique_ptr<BlockCacheTraceSimulator> cache_simulator_;
std::map<std::string, ColumnFamilyAccessInfoAggregate> cf_aggregates_map_;
std::map<std::string, BlockAccessInfo*> block_info_map_;
uint64_t trace_start_timestamp_in_seconds_ = 0;
uint64_t trace_end_timestamp_in_seconds_ = 0;
};
int block_cache_trace_analyzer_tool(int argc, char** argv);

262
tools/block_cache_trace_analyzer_test.cc
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@ -56,6 +56,12 @@ class BlockCacheTracerTest : public testing::Test {
reuse_distance_buckets_ = "1,1K,1M,1G";
reuse_interval_labels_ = "block,all,cf,sst,level,bt,cf_sst,cf_level,cf_bt";
reuse_interval_buckets_ = "1,10,100,1000";
reuse_lifetime_labels_ = "block,all,cf,sst,level,bt,cf_sst,cf_level,cf_bt";
reuse_lifetime_buckets_ = "1,10,100,1000";
analyzing_callers_ = "Get,Iterator";
access_count_buckets_ = "2,3,4,5,10";
analyze_get_spatial_locality_labels_ = "all";
analyze_get_spatial_locality_buckets_ = "10,20,30,40,50,60,70,80,90,100";
}
~BlockCacheTracerTest() override {
@ -158,12 +164,22 @@ class BlockCacheTracerTest : public testing::Test {
"-print_access_count_stats",
"-print_data_block_access_count_stats",
"-cache_sim_warmup_seconds=0",
"-analyze_bottom_k_access_count_blocks=5",
"-analyze_top_k_access_count_blocks=5",
"-analyze_blocks_reuse_k_reuse_window=5",
"-timeline_labels=" + timeline_labels_,
"-reuse_distance_labels=" + reuse_distance_labels_,
"-reuse_distance_buckets=" + reuse_distance_buckets_,
"-reuse_interval_labels=" + reuse_interval_labels_,
"-reuse_interval_buckets=" + reuse_interval_buckets_,
};
"-reuse_lifetime_labels=" + reuse_lifetime_labels_,
"-reuse_lifetime_buckets=" + reuse_lifetime_buckets_,
"-analyze_callers=" + analyzing_callers_,
"-access_count_buckets=" + access_count_buckets_,
"-analyze_get_spatial_locality_labels=" +
analyze_get_spatial_locality_labels_,
"-analyze_get_spatial_locality_buckets=" +
analyze_get_spatial_locality_buckets_};
char arg_buffer[kArgBufferSize];
char* argv[kMaxArgCount];
int argc = 0;
@ -189,6 +205,12 @@ class BlockCacheTracerTest : public testing::Test {
std::string reuse_distance_buckets_;
std::string reuse_interval_labels_;
std::string reuse_interval_buckets_;
std::string reuse_lifetime_labels_;
std::string reuse_lifetime_buckets_;
std::string analyzing_callers_;
std::string access_count_buckets_;
std::string analyze_get_spatial_locality_labels_;
std::string analyze_get_spatial_locality_buckets_;
};
TEST_F(BlockCacheTracerTest, BlockCacheAnalyzer) {
@ -247,51 +269,65 @@ TEST_F(BlockCacheTracerTest, BlockCacheAnalyzer) {
}
{
// Validate the timeline csv files.
const uint32_t expected_num_lines = 50;
std::stringstream ss(timeline_labels_);
while (ss.good()) {
std::string l;
ASSERT_TRUE(getline(ss, l, ','));
const std::string timeline_file =
test_path_ + "/" + l + "_access_timeline";
std::ifstream infile(timeline_file);
std::string line;
uint32_t nlines = 0;
ASSERT_TRUE(getline(infile, line));
uint64_t expected_time = 1;
while (getline(infile, line)) {
std::stringstream ss_naccess(line);
uint32_t naccesses = 0;
std::string substr;
uint32_t time = 0;
while (ss_naccess.good()) {
ASSERT_TRUE(getline(ss_naccess, substr, ','));
if (time == 0) {
time = ParseUint32(substr);
continue;
const std::vector<std::string> time_units{"_60", "_3600"};
const std::vector<std::string> user_access_only_flags{"user_access_only_",
"all_access_"};
for (auto const& user_access_only : user_access_only_flags) {
for (auto const& unit : time_units) {
std::stringstream ss(timeline_labels_);
while (ss.good()) {
std::string l;
ASSERT_TRUE(getline(ss, l, ','));
if (l.find("block") == std::string::npos) {
if (unit != "_60" || user_access_only != "all_access_") {
continue;
}
}
naccesses += ParseUint32(substr);
const std::string timeline_file = test_path_ + "/" +
user_access_only + l + unit +
"_access_timeline";
std::ifstream infile(timeline_file);
std::string line;
const uint64_t expected_naccesses = 50;
const uint64_t expected_user_accesses = 30;
ASSERT_TRUE(getline(infile, line)) << timeline_file;
uint32_t naccesses = 0;
while (getline(infile, line)) {
std::stringstream ss_naccess(line);
std::string substr;
bool read_label = false;
while (ss_naccess.good()) {
ASSERT_TRUE(getline(ss_naccess, substr, ','));
if (!read_label) {
read_label = true;
continue;
}
naccesses += ParseUint32(substr);
}
}
if (user_access_only == "user_access_only_") {
ASSERT_EQ(expected_user_accesses, naccesses) << timeline_file;
} else {
ASSERT_EQ(expected_naccesses, naccesses) << timeline_file;
}
ASSERT_OK(env_->DeleteFile(timeline_file));
}
nlines++;
ASSERT_EQ(1, naccesses);
ASSERT_EQ(expected_time, time);
expected_time += 1;
}
ASSERT_EQ(expected_num_lines, nlines);
ASSERT_OK(env_->DeleteFile(timeline_file));
}
}
{
// Validate the reuse_interval and reuse_distance csv files.
std::map<std::string, std::string> test_reuse_csv_files;
test_reuse_csv_files["_reuse_interval"] = reuse_interval_labels_;
test_reuse_csv_files["_access_reuse_interval"] = reuse_interval_labels_;
test_reuse_csv_files["_reuse_distance"] = reuse_distance_labels_;
test_reuse_csv_files["_reuse_lifetime"] = reuse_lifetime_labels_;
test_reuse_csv_files["_avg_reuse_interval"] = reuse_interval_labels_;
test_reuse_csv_files["_avg_reuse_interval_naccesses"] =
reuse_interval_labels_;
for (auto const& test : test_reuse_csv_files) {
const std::string& file_suffix = test.first;
const std::string& labels = test.second;
const uint32_t expected_num_rows = 10;
const uint32_t expected_num_rows_absolute_values = 5;
const uint32_t expected_reused_blocks = 0;
const uint32_t expected_num_rows = 5;
std::stringstream ss(labels);
while (ss.good()) {
std::string l;
@ -300,7 +336,6 @@ TEST_F(BlockCacheTracerTest, BlockCacheAnalyzer) {
std::ifstream infile(reuse_csv_file);
std::string line;
ASSERT_TRUE(getline(infile, line));
uint32_t nblocks = 0;
double npercentage = 0;
uint32_t nrows = 0;
while (getline(infile, line)) {
@ -314,20 +349,162 @@ TEST_F(BlockCacheTracerTest, BlockCacheAnalyzer) {
label_read = true;
continue;
}
if (nrows < expected_num_rows_absolute_values) {
nblocks += ParseUint32(substr);
} else {
npercentage += ParseDouble(substr);
}
npercentage += ParseDouble(substr);
}
}
ASSERT_EQ(expected_num_rows, nrows);
ASSERT_EQ(expected_reused_blocks, nblocks);
ASSERT_LT(npercentage, 0);
if ("_reuse_lifetime" == test.first ||
"_avg_reuse_interval" == test.first ||
"_avg_reuse_interval_naccesses" == test.first) {
ASSERT_EQ(100, npercentage) << reuse_csv_file;
} else {
ASSERT_LT(npercentage, 0);
}
ASSERT_OK(env_->DeleteFile(reuse_csv_file));
}
}
}
{
// Validate the percentage of accesses summary.
const std::string percent_access_summary_file =
test_path_ + "/percentage_of_accesses_summary";
std::ifstream infile(percent_access_summary_file);
std::string line;
ASSERT_TRUE(getline(infile, line));
std::set<std::string> callers;
std::set<std::string> expected_callers{"Get", "MultiGet", "Iterator",
"Prefetch", "Compaction"};
while (getline(infile, line)) {
std::stringstream caller_percent(line);
std::string caller;
ASSERT_TRUE(getline(caller_percent, caller, ','));
std::string percent;
ASSERT_TRUE(getline(caller_percent, percent, ','));
ASSERT_FALSE(caller_percent.good());
callers.insert(caller);
ASSERT_EQ(20, ParseDouble(percent));
}
ASSERT_EQ(expected_callers.size(), callers.size());
for (auto caller : callers) {
ASSERT_TRUE(expected_callers.find(caller) != expected_callers.end());
}
ASSERT_OK(env_->DeleteFile(percent_access_summary_file));
}
{
// Validate the percentage of accesses summary by analyzing callers.
std::stringstream analyzing_callers(analyzing_callers_);
while (analyzing_callers.good()) {
std::string caller;
ASSERT_TRUE(getline(analyzing_callers, caller, ','));
std::vector<std::string> breakdowns{"level", "bt"};
for (auto breakdown : breakdowns) {
const std::string file_name = test_path_ + "/" + caller + "_" +
breakdown +
"_percentage_of_accesses_summary";
std::ifstream infile(file_name);
std::string line;
ASSERT_TRUE(getline(infile, line));
double sum = 0;
while (getline(infile, line)) {
std::stringstream label_percent(line);
std::string label;
ASSERT_TRUE(getline(label_percent, label, ','));
std::string percent;
ASSERT_TRUE(getline(label_percent, percent, ','));
ASSERT_FALSE(label_percent.good());
sum += ParseDouble(percent);
}
ASSERT_EQ(100, sum);
ASSERT_OK(env_->DeleteFile(file_name));
}
}
}
const std::vector<std::string> access_types{"user_access_only", "all_access"};
const std::vector<std::string> prefix{"bt", "cf"};
for (auto const& pre : prefix) {
for (auto const& access_type : access_types) {
{
// Validate the access count summary.
const std::string bt_access_count_summary = test_path_ + "/" + pre +
"_" + access_type +
"_access_count_summary";
std::ifstream infile(bt_access_count_summary);
std::string line;
ASSERT_TRUE(getline(infile, line));
double sum_percent = 0;
while (getline(infile, line)) {
std::stringstream bt_percent(line);
std::string bt;
ASSERT_TRUE(getline(bt_percent, bt, ','));
std::string percent;
ASSERT_TRUE(getline(bt_percent, percent, ','));
sum_percent += ParseDouble(percent);
}
ASSERT_EQ(100.0, sum_percent);
ASSERT_OK(env_->DeleteFile(bt_access_count_summary));
}
}
}
for (auto const& access_type : access_types) {
std::vector<std::string> block_types{"Index", "Data", "Filter"};
for (auto block_type : block_types) {
// Validate reuse block timeline.
const std::string reuse_blocks_timeline = test_path_ + "/" + block_type +
"_" + access_type +
"_5_reuse_blocks_timeline";
std::ifstream infile(reuse_blocks_timeline);
std::string line;
ASSERT_TRUE(getline(infile, line)) << reuse_blocks_timeline;
uint32_t index = 0;
while (getline(infile, line)) {
std::stringstream timeline(line);
bool start_time = false;
double sum = 0;
while (timeline.good()) {
std::string value;
ASSERT_TRUE(getline(timeline, value, ','));
if (!start_time) {
start_time = true;
continue;
}
sum += ParseDouble(value);
}
index++;
ASSERT_LT(sum, 100.0 * index + 1) << reuse_blocks_timeline;
}
ASSERT_OK(env_->DeleteFile(reuse_blocks_timeline));
}
}
std::stringstream ss(analyze_get_spatial_locality_labels_);
while (ss.good()) {
std::string l;
ASSERT_TRUE(getline(ss, l, ','));
const std::vector<std::string> spatial_locality_files{
"_percent_ref_keys", "_percent_accesses_on_ref_keys",
"_percent_data_size_on_ref_keys"};
for (auto const& spatial_locality_file : spatial_locality_files) {
const std::string filename = test_path_ + "/" + l + spatial_locality_file;
std::ifstream infile(filename);
std::string line;
ASSERT_TRUE(getline(infile, line));
double sum_percent = 0;
uint32_t nrows = 0;
while (getline(infile, line)) {
std::stringstream bt_percent(line);
std::string bt;
ASSERT_TRUE(getline(bt_percent, bt, ','));
std::string percent;
ASSERT_TRUE(getline(bt_percent, percent, ','));
sum_percent += ParseDouble(percent);
nrows++;
}
ASSERT_EQ(11, nrows);
ASSERT_EQ(100.0, sum_percent);
ASSERT_OK(env_->DeleteFile(filename));
}
}
ASSERT_OK(env_->DeleteFile(block_cache_sim_config_path_));
}
@ -366,6 +543,7 @@ TEST_F(BlockCacheTracerTest, MixedBlocks) {
// Read blocks.
BlockCacheTraceAnalyzer analyzer(trace_file_path_,
/*output_miss_ratio_curve_path=*/"",
/*compute_reuse_distance=*/true,
/*simulator=*/nullptr);
// The analyzer ends when it detects an incomplete access record.
ASSERT_EQ(Status::Incomplete(""), analyzer.Analyze());

2
trace_replay/block_cache_tracer.cc
View File

@ -29,6 +29,8 @@ bool ShouldTrace(const Slice& block_key, const TraceOptions& trace_options) {
} // namespace
const uint64_t kMicrosInSecond = 1000 * 1000;
const uint64_t kSecondInMinute = 60;
const uint64_t kSecondInHour = 3600;
const std::string BlockCacheTraceHelper::kUnknownColumnFamilyName =
"UnknownColumnFamily";
const uint64_t BlockCacheTraceHelper::kReservedGetId = 0;

3
trace_replay/block_cache_tracer.h
View File

@ -17,6 +17,9 @@
namespace rocksdb {
extern const uint64_t kMicrosInSecond;
extern const uint64_t kSecondInMinute;
extern const uint64_t kSecondInHour;
class BlockCacheTraceHelper {
public: