1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#ifndef ROCKSDB_LITE
#include <map>
#include <queue>
#include <string>
#include <thread>
#include "monitoring/instrumented_mutex.h"
#include "port/port.h"
#include "rocksdb/status.h"
namespace rocksdb {
class Env;
class Logger;
class SstFileManagerImpl;
// DeleteScheduler allows the DB to enforce a rate limit on file deletion,
// Instead of deleteing files immediately, files are marked as trash
// and deleted in a background thread that apply sleep penlty between deletes
// if they are happening in a rate faster than rate_bytes_per_sec,
//
// Rate limiting can be turned off by setting rate_bytes_per_sec = 0, In this
// case DeleteScheduler will delete files immediately.
class DeleteScheduler {
public:
DeleteScheduler(Env* env, int64_t rate_bytes_per_sec, Logger* info_log,
SstFileManagerImpl* sst_file_manager,
double max_trash_db_ratio, uint64_t bytes_max_delete_chunk);
~DeleteScheduler();
// Return delete rate limit in bytes per second
int64_t GetRateBytesPerSecond() { return rate_bytes_per_sec_.load(); }
// Set delete rate limit in bytes per second
void SetRateBytesPerSecond(int64_t bytes_per_sec) {
rate_bytes_per_sec_.store(bytes_per_sec);
}
// Mark file as trash directory and schedule it's deletion
Status DeleteFile(const std::string& fname, const std::string& dir_to_sync);
// Wait for all files being deleteing in the background to finish or for
// destructor to be called.
void WaitForEmptyTrash();
// Return a map containing errors that happened in BackgroundEmptyTrash
// file_path => error status
std::map<std::string, Status> GetBackgroundErrors();
uint64_t GetTotalTrashSize() { return total_trash_size_.load(); }
// Return trash/DB size ratio where new files will be deleted immediately
double GetMaxTrashDBRatio() {
return max_trash_db_ratio_.load();
}
// Update trash/DB size ratio where new files will be deleted immediately
void SetMaxTrashDBRatio(double r) {
assert(r >= 0);
max_trash_db_ratio_.store(r);
}
static const std::string kTrashExtension;
static bool IsTrashFile(const std::string& file_path);
// Check if there are any .trash filse in path, and schedule their deletion
// Or delete immediately if sst_file_manager is nullptr
static Status CleanupDirectory(Env* env, SstFileManagerImpl* sfm,
const std::string& path);
private:
Status MarkAsTrash(const std::string& file_path, std::string* path_in_trash);
Status DeleteTrashFile(const std::string& path_in_trash,
const std::string& dir_to_sync,
uint64_t* deleted_bytes, bool* is_complete);
void BackgroundEmptyTrash();
Env* env_;
// total size of trash files
std::atomic<uint64_t> total_trash_size_;
// Maximum number of bytes that should be deleted per second
std::atomic<int64_t> rate_bytes_per_sec_;
// Mutex to protect queue_, pending_files_, bg_errors_, closing_
InstrumentedMutex mu_;
struct FileAndDir {
FileAndDir(const std::string& f, const std::string& d) : fname(f), dir(d) {}
std::string fname;
std::string dir; // empty will be skipped.
};
// Queue of trash files that need to be deleted
std::queue<FileAndDir> queue_;
// Number of trash files that are waiting to be deleted
int32_t pending_files_;
uint64_t bytes_max_delete_chunk_;
// Errors that happened in BackgroundEmptyTrash (file_path => error)
std::map<std::string, Status> bg_errors_;
bool num_link_error_printed_ = false;
// Set to true in ~DeleteScheduler() to force BackgroundEmptyTrash to stop
bool closing_;
// Condition variable signaled in these conditions
// - pending_files_ value change from 0 => 1
// - pending_files_ value change from 1 => 0
// - closing_ value is set to true
InstrumentedCondVar cv_;
// Background thread running BackgroundEmptyTrash
std::unique_ptr<port::Thread> bg_thread_;
// Mutex to protect threads from file name conflicts
InstrumentedMutex file_move_mu_;
Logger* info_log_;
SstFileManagerImpl* sst_file_manager_;
// If the trash size constitutes for more than this fraction of the total DB
// size we will start deleting new files passed to DeleteScheduler
// immediately
std::atomic<double> max_trash_db_ratio_;
static const uint64_t kMicrosInSecond = 1000 * 1000LL;
};
} // namespace rocksdb
#endif // ROCKSDB_LITE
|
