ceph/src/rocksdb/include/rocksdb/iostats_context.h

   1 // Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 #pragma once
   6
   7 #include <stdint.h>
   8
   9 #include <string>
  10
  11 #include "rocksdb/perf_level.h"
  12
  13 // A thread local context for gathering io-stats efficiently and transparently.
  14 // Use SetPerfLevel(PerfLevel::kEnableTime) to enable time stats.
  15
  16 namespace ROCKSDB_NAMESPACE {
  17
  18 // EXPERIMENTAL: the IO statistics for tiered storage. It matches with each
  19 // item in Temperature class.
  20 struct FileIOByTemperature {
  21   // the number of bytes read to Temperature::kHot file
  22   uint64_t hot_file_bytes_read;
  23   // the number of bytes read to Temperature::kWarm file
  24   uint64_t warm_file_bytes_read;
  25   // the number of bytes read to Temperature::kCold file
  26   uint64_t cold_file_bytes_read;
  27   // total number of reads to Temperature::kHot file
  28   uint64_t hot_file_read_count;
  29   // total number of reads to Temperature::kWarm file
  30   uint64_t warm_file_read_count;
  31   // total number of reads to Temperature::kCold file
  32   uint64_t cold_file_read_count;
  33   // reset all the statistics to 0.
  34   void Reset() {
  35     hot_file_bytes_read = 0;
  36     warm_file_bytes_read = 0;
  37     cold_file_bytes_read = 0;
  38     hot_file_read_count = 0;
  39     warm_file_read_count = 0;
  40     cold_file_read_count = 0;
  41   }
  42 };
  43
  44 struct IOStatsContext {
  45   // reset all io-stats counter to zero
  46   void Reset();
  47
  48   std::string ToString(bool exclude_zero_counters = false) const;
  49
  50   // the thread pool id
  51   uint64_t thread_pool_id;
  52
  53   // number of bytes that has been written.
  54   uint64_t bytes_written;
  55   // number of bytes that has been read.
  56   uint64_t bytes_read;
  57
  58   // time spent in open() and fopen().
  59   uint64_t open_nanos;
  60   // time spent in fallocate().
  61   uint64_t allocate_nanos;
  62   // time spent in write() and pwrite().
  63   uint64_t write_nanos;
  64   // time spent in read() and pread()
  65   uint64_t read_nanos;
  66   // time spent in sync_file_range().
  67   uint64_t range_sync_nanos;
  68   // time spent in fsync
  69   uint64_t fsync_nanos;
  70   // time spent in preparing write (fallocate etc).
  71   uint64_t prepare_write_nanos;
  72   // time spent in Logger::Logv().
  73   uint64_t logger_nanos;
  74   // CPU time spent in write() and pwrite()
  75   uint64_t cpu_write_nanos;
  76   // CPU time spent in read() and pread()
  77   uint64_t cpu_read_nanos;
  78
  79   FileIOByTemperature file_io_stats_by_temperature;
  80
  81   // It is not consistent that whether iostats follows PerfLevel.Timer counters
  82   // follows it but BackupEngine relies on counter metrics to always be there.
  83   // Here we create a backdoor option to disable some counters, so that some
  84   // existing stats are not polluted by file operations, such as logging, by
  85   // turning this off.
  86   bool disable_iostats = false;
  87 };
  88
  89 // If RocksDB is compiled with -DNIOSTATS_CONTEXT, then a pointer to a global,
  90 // non-thread-local IOStatsContext object will be returned. Attempts to update
  91 // this object will be ignored, and reading from it will also be no-op.
  92 // Otherwise, a pointer to a thread-local IOStatsContext object will be
  93 // returned.
  94 //
  95 // This function never returns nullptr.
  96 IOStatsContext* get_iostats_context();
  97
  98 }  // namespace ROCKSDB_NAMESPACE