rocksdb/include/leveldb/statistics.h
Abhishek Kona ec77366e14 Counters for bytes written and read.
Summary:
* Counters for bytes read and write.
as a part of this diff, I want to=>
* Measure compaction times. @dhruba can you point which function, should
* I time to get Compaction-times. Was looking at CompactRange.

Test Plan: db_test

Reviewers: dhruba, emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8763
2013-02-21 16:06:32 -08:00

149 lines
3.9 KiB
C++

// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#ifndef STORAGE_LEVELDB_INCLUDE_STATISTICS_H_
#define STORAGE_LEVELDB_INCLUDE_STATISTICS_H_
#include <cstddef>
#include <cstdint>
#include <string>
#include <memory>
namespace leveldb {
/**
* Keep adding ticker's here.
* Any ticker should have a value less than TICKER_ENUM_MAX.
* Add a new ticker by assigning it the current value of TICKER_ENUM_MAX
* And incrementing TICKER_ENUM_MAX.
*/
enum Tickers {
BLOCK_CACHE_MISS = 0,
BLOCK_CACHE_HIT = 1,
BLOOM_FILTER_USEFUL = 2, // no. of times bloom filter has avoided file reads.
/**
* COMPACTION_KEY_DROP_* count the reasons for key drop during compaction
* There are 3 reasons currently.
*/
COMPACTION_KEY_DROP_NEWER_ENTRY = 3, // key was written with a newer value.
COMPACTION_KEY_DROP_OBSOLETE = 4, // The key is obsolete.
COMPACTION_KEY_DROP_USER = 5, // user compaction function has dropped the key.
// Number of keys written to the database via the Put and Write call's
NUMBER_KEYS_WRITTEN = 6,
// Number of Keys read,
NUMBER_KEYS_READ = 7,
// Bytes written / read
BYTES_WRITTEN = 8,
BYTES_READ = 9,
TICKER_ENUM_MAX = 10,
};
/**
* Keep adding histogram's here.
* Any histogram whould have value less than HISTOGRAM_ENUM_MAX
* Add a new Histogram by assigning it the current value of HISTOGRAM_ENUM_MAX
* And increment HISTOGRAM_ENUM_MAX
*/
enum Histograms {
DB_GET = 0,
DB_WRITE = 1,
HISTOGRAM_ENUM_MAX = 2,
};
struct HistogramData {
double median;
double percentile95;
double percentile99;
double average;
double standard_deviation;
};
class Histogram {
public:
// clear's the histogram
virtual void Clear() = 0;
virtual ~Histogram();
// Add a value to be recorded in the histogram.
virtual void Add(uint64_t value) = 0;
virtual void Add(double value) = 0;
virtual std::string ToString() const = 0;
// Get statistics
virtual double Median() const = 0;
virtual double Percentile(double p) const = 0;
virtual double Average() const = 0;
virtual double StandardDeviation() const = 0;
virtual void Data(HistogramData * const data) const = 0;
};
/**
* A dumb ticker which keeps incrementing through its life time.
* Not thread safe. Locking is currently managed by external leveldb lock
*/
class Ticker {
public:
Ticker() : count_(0) { }
inline void recordTick() {
count_++;
}
inline void recordTick(int count) {
count_ += count;
}
inline uint64_t getCount() {
return count_;
}
private:
uint64_t count_;
};
// Analyze the performance of a db
class Statistics {
public:
// Create an Statistics object with default values for all fields.
Statistics() : numFileOpens_(0), numFileCloses_(0),
numFileErrors_(0) {}
virtual void incNumFileOpens() = 0;
virtual void incNumFileCloses() = 0;
virtual void incNumFileErrors() = 0;
virtual long getNumFileOpens() { return numFileOpens_;}
virtual long getNumFileCloses() { return numFileCloses_;}
virtual long getNumFileErrors() { return numFileErrors_;}
~Statistics() {}
virtual long getTickerCount(Tickers tickerType) = 0;
virtual void recordTick(Tickers tickerType, uint64_t count = 0) = 0;
virtual void measureTime(Histograms histogramType, uint64_t count) = 0;
virtual void measureTime(Histograms histogramType, double count) = 0;
virtual void histogramData(Histograms type, HistogramData * const data) = 0;
protected:
long numFileOpens_;
long numFileCloses_;
long numFileErrors_;
};
// Ease of Use functions
inline void RecordTick(Statistics* const statistics,
Tickers ticker,
uint64_t count = 1) {
if (statistics != nullptr) {
statistics->recordTick(ticker, count);
}
}
} // namespace leveldb
#endif // STORAGE_LEVELDB_INCLUDE_STATISTICS_H_