ceph/src/rocksdb/include/rocksdb/sst_file_manager.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
   6 #pragma once
   7
   8 #include <memory>
   9 #include <string>
  10 #include <unordered_map>
  11 #include <vector>
  12
  13 #include "rocksdb/file_system.h"
  14 #include "rocksdb/statistics.h"
  15 #include "rocksdb/status.h"
  16
  17 namespace ROCKSDB_NAMESPACE {
  18
  19 class Env;
  20 class Logger;
  21
  22 // SstFileManager is used to track SST and blob files in the DB and control
  23 // their deletion rate. All SstFileManager public functions are thread-safe.
  24 // SstFileManager is NOT an extensible interface but a public interface for
  25 // result of NewSstFileManager. Any derived classes must be RocksDB internal.
  26 class SstFileManager {
  27  public:
  28   virtual ~SstFileManager() {}
  29
  30   // Update the maximum allowed space that should be used by RocksDB, if
  31   // the total size of the SST and blob files exceeds max_allowed_space, writes
  32   // to RocksDB will fail.
  33   //
  34   // Setting max_allowed_space to 0 will disable this feature; maximum allowed
  35   // space will be infinite (Default value).
  36   //
  37   // thread-safe.
  38   virtual void SetMaxAllowedSpaceUsage(uint64_t max_allowed_space) = 0;
  39
  40   // Set the amount of buffer room each compaction should be able to leave.
  41   // In other words, at its maximum disk space consumption, the compaction
  42   // should still leave compaction_buffer_size available on the disk so that
  43   // other background functions may continue, such as logging and flushing.
  44   virtual void SetCompactionBufferSize(uint64_t compaction_buffer_size) = 0;
  45
  46   // Return true if the total size of SST  and blob files exceeded the maximum
  47   // allowed space usage.
  48   //
  49   // thread-safe.
  50   virtual bool IsMaxAllowedSpaceReached() = 0;
  51
  52   // Returns true if the total size of SST and blob files as well as estimated
  53   // size of ongoing compactions exceeds the maximums allowed space usage.
  54   virtual bool IsMaxAllowedSpaceReachedIncludingCompactions() = 0;
  55
  56   // Return the total size of all tracked files.
  57   // thread-safe
  58   virtual uint64_t GetTotalSize() = 0;
  59
  60   // Return a map containing all tracked files and their corresponding sizes.
  61   // thread-safe
  62   virtual std::unordered_map<std::string, uint64_t> GetTrackedFiles() = 0;
  63
  64   // Return delete rate limit in bytes per second.
  65   // thread-safe
  66   virtual int64_t GetDeleteRateBytesPerSecond() = 0;
  67
  68   // Update the delete rate limit in bytes per second.
  69   // zero means disable delete rate limiting and delete files immediately
  70   // thread-safe
  71   virtual void SetDeleteRateBytesPerSecond(int64_t delete_rate) = 0;
  72
  73   // Return trash/DB size ratio where new files will be deleted immediately
  74   // thread-safe
  75   virtual double GetMaxTrashDBRatio() = 0;
  76
  77   // Update trash/DB size ratio where new files will be deleted immediately
  78   // thread-safe
  79   virtual void SetMaxTrashDBRatio(double ratio) = 0;
  80
  81   // Return the total size of trash files
  82   // thread-safe
  83   virtual uint64_t GetTotalTrashSize() = 0;
  84
  85   // Set the statistics ptr to dump the stat information
  86   virtual void SetStatisticsPtr(const std::shared_ptr<Statistics>& stats) = 0;
  87 };
  88
  89 // Create a new SstFileManager that can be shared among multiple RocksDB
  90 // instances to track SST and blob files and control there deletion rate.
  91 // Even though SstFileManager don't track WAL files but it still control
  92 // there deletion rate.
  93 //
  94 // @param env: Pointer to Env object, please see "rocksdb/env.h".
  95 // @param fs: Pointer to FileSystem object (rocksdb/file_system.h"
  96 // @param info_log: If not nullptr, info_log will be used to log errors.
  97 //
  98 // == Deletion rate limiting specific arguments ==
  99 // @param trash_dir: Deprecated, this argument have no effect
 100 // @param rate_bytes_per_sec: How many bytes should be deleted per second, If
 101 //    this value is set to 1024 (1 Kb / sec) and we deleted a file of size 4 Kb
 102 //    in 1 second, we will wait for another 3 seconds before we delete other
 103 //    files, Set to 0 to disable deletion rate limiting.
 104 //    This option also affect the delete rate of WAL files in the DB.
 105 // @param delete_existing_trash: Deprecated, this argument have no effect, but
 106 //    if user provide trash_dir we will schedule deletes for files in the dir
 107 // @param status: If not nullptr, status will contain any errors that happened
 108 //    during creating the missing trash_dir or deleting existing files in trash.
 109 // @param max_trash_db_ratio: If the trash size constitutes for more than this
 110 //    fraction of the total DB size we will start deleting new files passed to
 111 //    DeleteScheduler immediately
 112 // @param bytes_max_delete_chunk: if a file to delete is larger than delete
 113 //    chunk, ftruncate the file by this size each time, rather than dropping the
 114 //    whole file. 0 means to always delete the whole file. If the file has more
 115 //    than one linked names, the file will be deleted as a whole. Either way,
 116 //    `rate_bytes_per_sec` will be appreciated. NOTE that with this option,
 117 //    files already renamed as a trash may be partial, so users should not
 118 //    directly recover them without checking.
 119 extern SstFileManager* NewSstFileManager(
 120     Env* env, std::shared_ptr<FileSystem> fs,
 121     std::shared_ptr<Logger> info_log = nullptr,
 122     const std::string& trash_dir = "", int64_t rate_bytes_per_sec = 0,
 123     bool delete_existing_trash = true, Status* status = nullptr,
 124     double max_trash_db_ratio = 0.25,
 125     uint64_t bytes_max_delete_chunk = 64 * 1024 * 1024);
 126
 127 // Same as above, but takes a pointer to a legacy Env object, instead of
 128 // Env and FileSystem objects
 129 extern SstFileManager* NewSstFileManager(
 130     Env* env, std::shared_ptr<Logger> info_log = nullptr,
 131     std::string trash_dir = "", int64_t rate_bytes_per_sec = 0,
 132     bool delete_existing_trash = true, Status* status = nullptr,
 133     double max_trash_db_ratio = 0.25,
 134     uint64_t bytes_max_delete_chunk = 64 * 1024 * 1024);
 135
 136 }  // namespace ROCKSDB_NAMESPACE