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statistics: make ticker and histogram extendible (#136)
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The changes are:
- make `StatisticsImpl` as a template
- remove internal stats due to facebook#4714
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@Connor1996
Connor1996 authored and yiwu-arbug committed Jan 7, 2020
1 parent ebec1bd commit c7d7751
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Showing 6 changed files with 321 additions and 280 deletions.
3 changes: 1 addition & 2 deletions db/c.cc
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Expand Up @@ -2635,12 +2635,11 @@ void rocksdb_options_set_memtable_huge_page_size(rocksdb_options_t* opt,
opt->rep.memtable_huge_page_size = v;
}

void rocksdb_options_set_doubly_skip_list_rep(rocksdb_options_t *opt) {
void rocksdb_options_set_doubly_skip_list_rep(rocksdb_options_t* opt) {
rocksdb::MemTableRepFactory* factory = new rocksdb::DoublySkipListFactory();
opt->rep.memtable_factory.reset(factory);
}


void rocksdb_options_set_hash_skip_list_rep(
rocksdb_options_t *opt, size_t bucket_count,
int32_t skiplist_height, int32_t skiplist_branching_factor) {
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2 changes: 2 additions & 0 deletions include/rocksdb/statistics.h
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Expand Up @@ -539,6 +539,8 @@ class Statistics {
};

// Create a concrete DBStatistics object
template <uint32_t TICKER_MAX = TICKER_ENUM_MAX,
uint32_t HISTOGRAM_MAX = HISTOGRAM_ENUM_MAX>
std::shared_ptr<Statistics> CreateDBStatistics();

} // namespace rocksdb
3 changes: 2 additions & 1 deletion java/rocksjni/statisticsjni.h
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Expand Up @@ -14,10 +14,11 @@
#include <string>
#include "rocksdb/statistics.h"
#include "monitoring/statistics.h"
#include "monitoring/statistics_impl.h"

namespace rocksdb {

class StatisticsJni : public StatisticsImpl {
class StatisticsJni : public StatisticsImpl<> {
public:
StatisticsJni(std::shared_ptr<Statistics> stats);
StatisticsJni(std::shared_ptr<Statistics> stats,
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185 changes: 5 additions & 180 deletions monitoring/statistics.cc
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Expand Up @@ -3,17 +3,16 @@
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
#include "monitoring/statistics.h"

#include <cinttypes>
#include "rocksdb/statistics.h"
#include "port/likely.h"
#include <algorithm>
#include <cstdio>

#include <cinttypes>

#include "monitoring/statistics_impl.h"

namespace rocksdb {

// The order of items listed in Tickers should be the same as
// The order of items listed in Tickers should be the same as
// the order listed in TickersNameMap
const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
{BLOCK_CACHE_MISS, "rocksdb.block.cache.miss"},
Expand Down Expand Up @@ -228,178 +227,4 @@ const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
{SST_BATCH_SIZE, "rocksdb.sst.batch.size"},
};

std::shared_ptr<Statistics> CreateDBStatistics() {
return std::make_shared<StatisticsImpl>(nullptr);
}

StatisticsImpl::StatisticsImpl(std::shared_ptr<Statistics> stats)
: stats_(std::move(stats)) {}

StatisticsImpl::~StatisticsImpl() {}

uint64_t StatisticsImpl::getTickerCount(uint32_t tickerType) const {
MutexLock lock(&aggregate_lock_);
return getTickerCountLocked(tickerType);
}

uint64_t StatisticsImpl::getTickerCountLocked(uint32_t tickerType) const {
assert(tickerType < TICKER_ENUM_MAX);
uint64_t res = 0;
for (size_t core_idx = 0; core_idx < per_core_stats_.Size(); ++core_idx) {
res += per_core_stats_.AccessAtCore(core_idx)->tickers_[tickerType];
}
return res;
}

void StatisticsImpl::histogramData(uint32_t histogramType,
HistogramData* const data) const {
MutexLock lock(&aggregate_lock_);
getHistogramImplLocked(histogramType)->Data(data);
}

std::unique_ptr<HistogramImpl> StatisticsImpl::getHistogramImplLocked(
uint32_t histogramType) const {
assert(histogramType < HISTOGRAM_ENUM_MAX);
std::unique_ptr<HistogramImpl> res_hist(new HistogramImpl());
for (size_t core_idx = 0; core_idx < per_core_stats_.Size(); ++core_idx) {
res_hist->Merge(
per_core_stats_.AccessAtCore(core_idx)->histograms_[histogramType]);
}
return res_hist;
}

std::string StatisticsImpl::getHistogramString(uint32_t histogramType) const {
MutexLock lock(&aggregate_lock_);
return getHistogramImplLocked(histogramType)->ToString();
}

void StatisticsImpl::setTickerCount(uint32_t tickerType, uint64_t count) {
{
MutexLock lock(&aggregate_lock_);
setTickerCountLocked(tickerType, count);
}
if (stats_ && tickerType < TICKER_ENUM_MAX) {
stats_->setTickerCount(tickerType, count);
}
}

void StatisticsImpl::setTickerCountLocked(uint32_t tickerType, uint64_t count) {
assert(tickerType < TICKER_ENUM_MAX);
for (size_t core_idx = 0; core_idx < per_core_stats_.Size(); ++core_idx) {
if (core_idx == 0) {
per_core_stats_.AccessAtCore(core_idx)->tickers_[tickerType] = count;
} else {
per_core_stats_.AccessAtCore(core_idx)->tickers_[tickerType] = 0;
}
}
}

uint64_t StatisticsImpl::getAndResetTickerCount(uint32_t tickerType) {
uint64_t sum = 0;
{
MutexLock lock(&aggregate_lock_);
assert(tickerType < TICKER_ENUM_MAX);
for (size_t core_idx = 0; core_idx < per_core_stats_.Size(); ++core_idx) {
sum +=
per_core_stats_.AccessAtCore(core_idx)->tickers_[tickerType].exchange(
0, std::memory_order_relaxed);
}
}
if (stats_ && tickerType < TICKER_ENUM_MAX) {
stats_->setTickerCount(tickerType, 0);
}
return sum;
}

void StatisticsImpl::recordTick(uint32_t tickerType, uint64_t count) {
assert(tickerType < TICKER_ENUM_MAX);
per_core_stats_.Access()->tickers_[tickerType].fetch_add(
count, std::memory_order_relaxed);
if (stats_ && tickerType < TICKER_ENUM_MAX) {
stats_->recordTick(tickerType, count);
}
}

void StatisticsImpl::recordInHistogram(uint32_t histogramType, uint64_t value) {
assert(histogramType < HISTOGRAM_ENUM_MAX);
if (get_stats_level() <= StatsLevel::kExceptHistogramOrTimers) {
return;
}
per_core_stats_.Access()->histograms_[histogramType].Add(value);
if (stats_ && histogramType < HISTOGRAM_ENUM_MAX) {
stats_->recordInHistogram(histogramType, value);
}
}

Status StatisticsImpl::Reset() {
MutexLock lock(&aggregate_lock_);
for (uint32_t i = 0; i < TICKER_ENUM_MAX; ++i) {
setTickerCountLocked(i, 0);
}
for (uint32_t i = 0; i < HISTOGRAM_ENUM_MAX; ++i) {
for (size_t core_idx = 0; core_idx < per_core_stats_.Size(); ++core_idx) {
per_core_stats_.AccessAtCore(core_idx)->histograms_[i].Clear();
}
}
return Status::OK();
}

namespace {

// a buffer size used for temp string buffers
const int kTmpStrBufferSize = 200;

} // namespace

std::string StatisticsImpl::ToString() const {
MutexLock lock(&aggregate_lock_);
std::string res;
res.reserve(20000);
for (const auto& t : TickersNameMap) {
assert(t.first < TICKER_ENUM_MAX);
char buffer[kTmpStrBufferSize];
snprintf(buffer, kTmpStrBufferSize, "%s COUNT : %" PRIu64 "\n",
t.second.c_str(), getTickerCountLocked(t.first));
res.append(buffer);
}
for (const auto& h : HistogramsNameMap) {
assert(h.first < HISTOGRAM_ENUM_MAX);
char buffer[kTmpStrBufferSize];
HistogramData hData;
getHistogramImplLocked(h.first)->Data(&hData);
// don't handle failures - buffer should always be big enough and arguments
// should be provided correctly
int ret =
snprintf(buffer, kTmpStrBufferSize,
"%s P50 : %f P95 : %f P99 : %f P100 : %f COUNT : %" PRIu64
" SUM : %" PRIu64 "\n",
h.second.c_str(), hData.median, hData.percentile95,
hData.percentile99, hData.max, hData.count, hData.sum);
if (ret < 0 || ret >= kTmpStrBufferSize) {
assert(false);
continue;
}
res.append(buffer);
}
res.shrink_to_fit();
return res;
}

bool StatisticsImpl::getTickerMap(
std::map<std::string, uint64_t>* stats_map) const {
assert(stats_map);
if (!stats_map) return false;
stats_map->clear();
MutexLock lock(&aggregate_lock_);
for (const auto& t : TickersNameMap) {
assert(t.first < TICKER_ENUM_MAX);
(*stats_map)[t.second.c_str()] = getTickerCountLocked(t.first);
}
return true;
}

bool StatisticsImpl::HistEnabledForType(uint32_t type) const {
return type < HISTOGRAM_ENUM_MAX;
}

} // namespace rocksdb
100 changes: 3 additions & 97 deletions monitoring/statistics.h
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Original file line number Diff line number Diff line change
Expand Up @@ -4,108 +4,14 @@
// (found in the LICENSE.Apache file in the root directory).
//
#pragma once
#include "rocksdb/statistics.h"

#include <atomic>
#include <map>
#include <string>
#include <vector>
#include <cinttypes>

#include "monitoring/histogram.h"
#include "port/likely.h"
#include "port/port.h"
#include "util/core_local.h"
#include "util/mutexlock.h"

#ifdef __clang__
#define ROCKSDB_FIELD_UNUSED __attribute__((__unused__))
#else
#define ROCKSDB_FIELD_UNUSED
#endif // __clang__

#ifndef STRINGIFY
#define STRINGIFY(x) #x
#define TOSTRING(x) STRINGIFY(x)
#endif
#include "rocksdb/statistics.h"

namespace rocksdb {

enum TickersInternal : uint32_t {
INTERNAL_TICKER_ENUM_START = TICKER_ENUM_MAX,
INTERNAL_TICKER_ENUM_MAX
};

enum HistogramsInternal : uint32_t {
INTERNAL_HISTOGRAM_START = HISTOGRAM_ENUM_MAX,
INTERNAL_HISTOGRAM_ENUM_MAX
};

class StatisticsImpl : public Statistics {
public:
StatisticsImpl(std::shared_ptr<Statistics> stats);
virtual ~StatisticsImpl();

virtual uint64_t getTickerCount(uint32_t ticker_type) const override;
virtual void histogramData(uint32_t histogram_type,
HistogramData* const data) const override;
std::string getHistogramString(uint32_t histogram_type) const override;

virtual void setTickerCount(uint32_t ticker_type, uint64_t count) override;
virtual uint64_t getAndResetTickerCount(uint32_t ticker_type) override;
virtual void recordTick(uint32_t ticker_type, uint64_t count) override;
// The function is implemented for now for backward compatibility reason.
// In case a user explictly calls it, for example, they may have a wrapped
// Statistics object, passing the call to recordTick() into here, nothing
// will break.
void measureTime(uint32_t histogramType, uint64_t time) override {
recordInHistogram(histogramType, time);
}
virtual void recordInHistogram(uint32_t histogram_type,
uint64_t value) override;

virtual Status Reset() override;
virtual std::string ToString() const override;
virtual bool getTickerMap(std::map<std::string, uint64_t>*) const override;
virtual bool HistEnabledForType(uint32_t type) const override;

private:
// If non-nullptr, forwards updates to the object pointed to by `stats_`.
std::shared_ptr<Statistics> stats_;
// Synchronizes anything that operates across other cores' local data,
// such that operations like Reset() can be performed atomically.
mutable port::Mutex aggregate_lock_;

// The ticker/histogram data are stored in this structure, which we will store
// per-core. It is cache-aligned, so tickers/histograms belonging to different
// cores can never share the same cache line.
//
// Alignment attributes expand to nothing depending on the platform
struct ALIGN_AS(CACHE_LINE_SIZE) StatisticsData {
std::atomic_uint_fast64_t tickers_[INTERNAL_TICKER_ENUM_MAX] = {{0}};
HistogramImpl histograms_[INTERNAL_HISTOGRAM_ENUM_MAX];
#ifndef HAVE_ALIGNED_NEW
char
padding[(CACHE_LINE_SIZE -
(INTERNAL_TICKER_ENUM_MAX * sizeof(std::atomic_uint_fast64_t) +
INTERNAL_HISTOGRAM_ENUM_MAX * sizeof(HistogramImpl)) %
CACHE_LINE_SIZE)] ROCKSDB_FIELD_UNUSED;
#endif
void *operator new(size_t s) { return port::cacheline_aligned_alloc(s); }
void *operator new[](size_t s) { return port::cacheline_aligned_alloc(s); }
void operator delete(void *p) { port::cacheline_aligned_free(p); }
void operator delete[](void *p) { port::cacheline_aligned_free(p); }
};

static_assert(sizeof(StatisticsData) % CACHE_LINE_SIZE == 0, "Expected " TOSTRING(CACHE_LINE_SIZE) "-byte aligned");

CoreLocalArray<StatisticsData> per_core_stats_;

uint64_t getTickerCountLocked(uint32_t ticker_type) const;
std::unique_ptr<HistogramImpl> getHistogramImplLocked(
uint32_t histogram_type) const;
void setTickerCountLocked(uint32_t ticker_type, uint64_t count);
};

// Utility functions
inline void RecordInHistogram(Statistics* statistics, uint32_t histogram_type,
uint64_t value) {
Expand Down Expand Up @@ -135,4 +41,4 @@ inline void SetTickerCount(Statistics* statistics, uint32_t ticker_type,
}
}

}
} // namespace rocksdb
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