forked from lni/dragonboat
-
Notifications
You must be signed in to change notification settings - Fork 0
/
snapshotter.go
412 lines (379 loc) · 10.4 KB
/
snapshotter.go
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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
// Copyright 2017-2021 Lei Ni ([email protected]) and other contributors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package dragonboat
import (
"strconv"
"github.com/cockroachdb/errors"
"github.com/lni/goutils/logutil"
"github.com/lni/dragonboat/v4/internal/fileutil"
"github.com/lni/dragonboat/v4/internal/logdb"
"github.com/lni/dragonboat/v4/internal/rsm"
"github.com/lni/dragonboat/v4/internal/server"
"github.com/lni/dragonboat/v4/internal/utils/dio"
"github.com/lni/dragonboat/v4/internal/vfs"
"github.com/lni/dragonboat/v4/raftio"
pb "github.com/lni/dragonboat/v4/raftpb"
sm "github.com/lni/dragonboat/v4/statemachine"
)
func compressionType(ct pb.CompressionType) dio.CompressionType {
if ct == pb.NoCompression {
return dio.NoCompression
} else if ct == pb.Snappy {
return dio.Snappy
} else {
plog.Panicf("unknown compression type: %d", ct)
}
panic("will never reach here")
}
var (
// ErrNoSnapshot is the error used to indicate that there is no snapshot
// available.
ErrNoSnapshot = errors.New("no snapshot available")
errSnapshotOutOfDate = errors.New("snapshot being generated is out of date")
)
type snapshotter struct {
root server.SnapshotDirFunc
dir string
shardID uint64
replicaID uint64
logdb raftio.ILogDB
logReader *logdb.LogReader
fs vfs.IFS
}
var _ rsm.ISnapshotter = (*snapshotter)(nil)
func newSnapshotter(shardID uint64, replicaID uint64,
root server.SnapshotDirFunc, ldb raftio.ILogDB,
logReader *logdb.LogReader, fs vfs.IFS) *snapshotter {
return &snapshotter{
shardID: shardID,
replicaID: replicaID,
root: root,
dir: root(shardID, replicaID),
logdb: ldb,
logReader: logReader,
fs: fs,
}
}
func (s *snapshotter) id() string {
return dn(s.shardID, s.replicaID)
}
func (s *snapshotter) ssid(index uint64) string {
return logutil.DescribeSS(s.shardID, s.replicaID, index)
}
func (s *snapshotter) Shrunk(ss pb.Snapshot) (bool, error) {
return rsm.IsShrunkSnapshotFile(s.getFilePath(ss.Index), s.fs)
}
func (s *snapshotter) Stream(streamable rsm.IStreamable,
meta rsm.SSMeta, sink pb.IChunkSink) error {
ct := compressionType(meta.CompressionType)
cw := dio.NewCompressor(ct, rsm.NewChunkWriter(sink, meta))
if err := streamable.Stream(meta.Ctx, cw); err != nil {
if cerr := sink.Close(); cerr != nil {
plog.Errorf("failed to close the sink %v", cerr)
}
return err
}
return cw.Close()
}
func (s *snapshotter) Save(savable rsm.ISavable,
meta rsm.SSMeta) (ss pb.Snapshot, env server.SSEnv, err error) {
env = s.getCustomEnv(meta)
if err := env.CreateTempDir(); err != nil {
return pb.Snapshot{}, env, err
}
files := rsm.NewFileCollection()
fp := env.GetTempFilepath()
ct := compressionType(meta.CompressionType)
w, err := rsm.NewSnapshotWriter(fp, meta.CompressionType, s.fs)
if err != nil {
return pb.Snapshot{}, env, err
}
cw := dio.NewCountedWriter(w)
sw := dio.NewCompressor(ct, cw)
defer func() {
err = firstError(err, sw.Close())
if ss.Index > 0 {
total := cw.BytesWritten()
ss.Checksum = w.GetPayloadChecksum()
ss.FileSize = w.GetPayloadSize(total) + rsm.HeaderSize
}
}()
session := meta.Session.Bytes()
dummy, err := savable.Save(meta, sw, session, files)
if err != nil {
return pb.Snapshot{}, env, err
}
fs, err := files.PrepareFiles(env.GetTempDir(), env.GetFinalDir())
if err != nil {
return pb.Snapshot{}, env, err
}
return pb.Snapshot{
ShardID: s.shardID,
Filepath: env.GetFilepath(),
Membership: meta.Membership,
Index: meta.Index,
Term: meta.Term,
OnDiskIndex: meta.OnDiskIndex,
Files: fs,
Dummy: dummy,
Type: meta.Type,
}, env, nil
}
func (s *snapshotter) Load(ss pb.Snapshot,
sessions rsm.ILoadable, asm rsm.IRecoverable) (err error) {
fp := s.getFilePath(ss.Index)
fs := make([]sm.SnapshotFile, 0)
for _, f := range ss.Files {
fs = append(fs, sm.SnapshotFile{
FileID: f.FileId,
Filepath: f.Filepath,
Metadata: f.Metadata,
})
}
reader, header, err := rsm.NewSnapshotReader(fp, s.fs)
if err != nil {
return err
}
ct := compressionType(header.CompressionType)
cr := dio.NewDecompressor(ct, reader)
defer func() {
err = firstError(err, cr.Close())
}()
v := rsm.SSVersion(header.Version)
if err := sessions.LoadSessions(cr, v); err != nil {
return err
}
if err := asm.Recover(cr, fs); err != nil {
return err
}
return nil
}
func (s *snapshotter) GetSnapshot() (pb.Snapshot, error) {
ss := s.logReader.Snapshot()
if pb.IsEmptySnapshot(ss) {
return pb.Snapshot{}, ErrNoSnapshot
}
return ss, nil
}
// TODO: update this once the LogDB interface is updated to have the ability to
// query latest snapshot.
func (s *snapshotter) GetSnapshotFromLogDB() (pb.Snapshot, error) {
snapshot, err := s.logdb.GetSnapshot(s.shardID, s.replicaID)
if err != nil {
return pb.Snapshot{}, err
}
if !pb.IsEmptySnapshot(snapshot) {
return snapshot, nil
}
return pb.Snapshot{}, ErrNoSnapshot
}
func (s *snapshotter) Shrink(index uint64) error {
ss, err := s.logdb.GetSnapshot(s.shardID, s.replicaID)
if err != nil {
return err
}
if ss.Index < index {
return nil
}
if !ss.Dummy && !ss.Witness {
env := s.getEnv(index)
fp := env.GetFilepath()
shrunk := env.GetShrinkedFilepath()
plog.Infof("%s shrinking %s", s.id(), s.ssid(index))
if err := rsm.ShrinkSnapshot(fp, shrunk, s.fs); err != nil {
return err
}
return rsm.ReplaceSnapshot(shrunk, fp, s.fs)
}
return nil
}
func (s *snapshotter) Compact(index uint64) error {
ss, err := s.logdb.GetSnapshot(s.shardID, s.replicaID)
if err != nil {
return err
}
if ss.Index <= index {
plog.Panicf("%s invalid compaction, LogDB snapshot %d, index %d",
s.id(), ss.Index, index)
}
plog.Debugf("%s called Compact, latest %d, to compact %d",
s.id(), ss.Index, index)
if err := s.remove(index); err != nil {
return err
}
return nil
}
func (s *snapshotter) IsNoSnapshotError(err error) bool {
return errors.Is(err, ErrNoSnapshot)
}
func (s *snapshotter) Commit(ss pb.Snapshot, req rsm.SSRequest) error {
env := s.getCustomEnv(rsm.SSMeta{
Index: ss.Index,
Request: req,
})
if err := env.SaveSSMetadata(&ss); err != nil {
return err
}
if err := env.FinalizeSnapshot(&ss); err != nil {
if errors.Is(err, server.ErrSnapshotOutOfDate) {
return errSnapshotOutOfDate
}
return err
}
if !req.Exported() {
if err := s.saveSnapshot(ss); err != nil {
return err
}
}
return env.RemoveFlagFile()
}
func (s *snapshotter) getFilePath(index uint64) string {
env := s.getEnv(index)
return env.GetFilepath()
}
func (s *snapshotter) processOrphans() error {
files, err := s.fs.List(s.dir)
if err != nil {
return err
}
noss := false
mrss, err := s.GetSnapshotFromLogDB()
if err != nil {
if errors.Is(err, ErrNoSnapshot) {
noss = true
} else {
return err
}
}
removeFolder := func(fdir string) error {
if err := s.fs.RemoveAll(fdir); err != nil {
return err
}
return fileutil.SyncDir(s.dir, s.fs)
}
for _, n := range files {
fi, err := s.fs.Stat(s.fs.PathJoin(s.dir, n))
if err != nil {
return err
}
if !fi.IsDir() {
continue
}
fdir := s.fs.PathJoin(s.dir, fi.Name())
if s.isOrphan(fi.Name()) {
var ss pb.Snapshot
if err := fileutil.GetFlagFileContent(fdir,
fileutil.SnapshotFlagFilename, &ss, s.fs); err != nil {
return err
}
if pb.IsEmptySnapshot(ss) {
plog.Panicf("empty snapshot found in %s", fdir)
}
remove := false
if noss {
remove = true
} else {
if mrss.Index != ss.Index {
remove = true
}
}
if remove {
if err := s.remove(ss.Index); err != nil {
return err
}
} else {
env := s.getEnv(ss.Index)
if err := env.RemoveFlagFile(); err != nil {
return err
}
}
} else if s.isZombie(fi.Name()) {
if err := removeFolder(fdir); err != nil {
return err
}
} else if s.isSnapshot(fi.Name()) {
index := s.parseIndex(fi.Name())
if noss || index != mrss.Index {
if err := removeFolder(fdir); err != nil {
return err
}
}
}
}
return nil
}
func (s *snapshotter) remove(index uint64) error {
env := s.getEnv(index)
return env.RemoveFinalDir()
}
func (s *snapshotter) removeFlagFile(index uint64) error {
env := s.getEnv(index)
return env.RemoveFlagFile()
}
func (s *snapshotter) getEnv(index uint64) server.SSEnv {
return server.NewSSEnv(s.root,
s.shardID, s.replicaID, index, s.replicaID, server.SnapshotMode, s.fs)
}
func (s *snapshotter) getCustomEnv(meta rsm.SSMeta) server.SSEnv {
if meta.Request.Exported() {
if len(meta.Request.Path) == 0 {
plog.Panicf("Path is empty when exporting snapshot")
}
gp := func(shardID uint64, replicaID uint64) string {
return meta.Request.Path
}
return server.NewSSEnv(gp,
s.shardID, s.replicaID, meta.Index, s.replicaID, server.SnapshotMode, s.fs)
}
return s.getEnv(meta.Index)
}
func (s *snapshotter) saveSnapshot(snapshot pb.Snapshot) error {
return s.logdb.SaveSnapshots([]pb.Update{{
ShardID: s.shardID,
ReplicaID: s.replicaID,
Snapshot: snapshot,
}})
}
func (s *snapshotter) dirMatch(dir string) bool {
return server.SnapshotDirNameRe.Match([]byte(dir))
}
func (s *snapshotter) parseIndex(dir string) uint64 {
if parts := server.SnapshotDirNamePartsRe.FindStringSubmatch(dir); len(parts) == 2 {
index, err := strconv.ParseUint(parts[1], 16, 64)
if err != nil {
plog.Panicf("failed to parse index %s", parts[1])
}
return index
}
plog.Panicf("unknown snapshot fold name: %s", dir)
return 0
}
func (s *snapshotter) isSnapshot(dir string) bool {
if !s.dirMatch(dir) {
return false
}
fdir := s.fs.PathJoin(s.dir, dir)
return !fileutil.HasFlagFile(fdir, fileutil.SnapshotFlagFilename, s.fs)
}
func (s *snapshotter) isZombie(dir string) bool {
return server.GenSnapshotDirNameRe.Match([]byte(dir)) ||
server.RecvSnapshotDirNameRe.Match([]byte(dir))
}
func (s *snapshotter) isOrphan(dir string) bool {
if !s.dirMatch(dir) {
return false
}
fdir := s.fs.PathJoin(s.dir, dir)
return fileutil.HasFlagFile(fdir, fileutil.SnapshotFlagFilename, s.fs)
}