forked from pingcap/tidb
-
Notifications
You must be signed in to change notification settings - Fork 0
/
update.go
613 lines (575 loc) · 17.7 KB
/
update.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
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
// Copyright 2017 PingCAP, Inc.
//
// 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
//
// http://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,
// See the License for the specific language governing permissions and
// limitations under the License.
package statistics
import (
"fmt"
"math"
"strconv"
"sync"
"time"
"github.com/juju/errors"
"github.com/pingcap/tidb/infoschema"
"github.com/pingcap/tidb/metrics"
"github.com/pingcap/tidb/model"
"github.com/pingcap/tidb/mysql"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/sessionctx/variable"
"github.com/pingcap/tidb/store/tikv/oracle"
"github.com/pingcap/tidb/util/sqlexec"
log "github.com/sirupsen/logrus"
"golang.org/x/net/context"
)
type tableDeltaMap map[int64]variable.TableDelta
func (m tableDeltaMap) update(id int64, delta int64, count int64, colSize *map[int64]int64) {
item := m[id]
item.Delta += delta
item.Count += count
if item.ColSize == nil {
item.ColSize = make(map[int64]int64)
}
if colSize != nil {
for key, val := range *colSize {
item.ColSize[key] += val
}
}
m[id] = item
}
type errorRateDelta struct {
PkID int64
PkErrorRate *ErrorRate
IdxErrorRate map[int64]*ErrorRate
}
type errorRateDeltaMap map[int64]errorRateDelta
func (m errorRateDeltaMap) update(tableID int64, histID int64, rate float64, isIndex bool) {
item := m[tableID]
if isIndex {
if item.IdxErrorRate == nil {
item.IdxErrorRate = make(map[int64]*ErrorRate)
}
if item.IdxErrorRate[histID] == nil {
item.IdxErrorRate[histID] = &ErrorRate{}
}
item.IdxErrorRate[histID].update(rate)
} else {
if item.PkErrorRate == nil {
item.PkID = histID
item.PkErrorRate = &ErrorRate{}
}
item.PkErrorRate.update(rate)
}
m[tableID] = item
}
func (m errorRateDeltaMap) merge(deltaMap errorRateDeltaMap) {
for tableID, item := range deltaMap {
tbl := m[tableID]
for histID, errorRate := range item.IdxErrorRate {
if tbl.IdxErrorRate == nil {
tbl.IdxErrorRate = make(map[int64]*ErrorRate)
}
if tbl.IdxErrorRate[histID] == nil {
tbl.IdxErrorRate[histID] = &ErrorRate{}
}
tbl.IdxErrorRate[histID].merge(errorRate)
}
if item.PkErrorRate != nil {
if tbl.PkErrorRate == nil {
tbl.PkID = item.PkID
tbl.PkErrorRate = &ErrorRate{}
}
tbl.PkErrorRate.merge(item.PkErrorRate)
}
m[tableID] = tbl
}
}
func (m errorRateDeltaMap) clear(tableID int64, histID int64, isIndex bool) {
item := m[tableID]
if isIndex {
delete(item.IdxErrorRate, histID)
} else {
item.PkErrorRate = nil
}
m[tableID] = item
}
func (h *Handle) merge(s *SessionStatsCollector) {
s.Lock()
defer s.Unlock()
for id, item := range s.mapper {
h.globalMap.update(id, item.Delta, item.Count, &item.ColSize)
}
h.rateMap.merge(s.rateMap)
s.rateMap = make(errorRateDeltaMap)
h.feedback = mergeQueryFeedback(h.feedback, s.feedback)
s.mapper = make(tableDeltaMap)
s.feedback = s.feedback[:0]
}
// SessionStatsCollector is a list item that holds the delta mapper. If you want to write or read mapper, you must lock it.
type SessionStatsCollector struct {
sync.Mutex
mapper tableDeltaMap
feedback []*QueryFeedback
rateMap errorRateDeltaMap
prev *SessionStatsCollector
next *SessionStatsCollector
// deleted is set to true when a session is closed. Every time we sweep the list, we will remove the useless collector.
deleted bool
}
// Delete only sets the deleted flag true, it will be deleted from list when DumpStatsDeltaToKV is called.
func (s *SessionStatsCollector) Delete() {
s.Lock()
defer s.Unlock()
s.deleted = true
}
// Update will updates the delta and count for one table id.
func (s *SessionStatsCollector) Update(id int64, delta int64, count int64, colSize *map[int64]int64) {
s.Lock()
defer s.Unlock()
s.mapper.update(id, delta, count, colSize)
}
func mergeQueryFeedback(lq []*QueryFeedback, rq []*QueryFeedback) []*QueryFeedback {
for _, q := range rq {
if len(lq) >= MaxQueryFeedbackCount {
break
}
lq = append(lq, q)
}
return lq
}
// StoreQueryFeedback will merges the feedback into stats collector.
func (s *SessionStatsCollector) StoreQueryFeedback(feedback interface{}, h *Handle) error {
q := feedback.(*QueryFeedback)
// TODO: If the error rate is small or actual scan count is small, we do not need to store the feed back.
if !q.valid || q.hist == nil {
return nil
}
err := q.recalculateExpectCount(h)
if err != nil {
return errors.Trace(err)
}
expected := float64(q.expected)
var rate float64
if q.actual == 0 {
if expected == 0 {
rate = 0
} else {
rate = 1
}
} else {
rate = math.Abs(expected-float64(q.actual)) / float64(q.actual)
}
metrics.StatsInaccuracyRate.Observe(rate)
s.Lock()
defer s.Unlock()
isIndex := q.hist.tp.Tp == mysql.TypeBlob
s.rateMap.update(q.tableID, q.hist.ID, rate, isIndex)
if len(s.feedback) < MaxQueryFeedbackCount {
s.feedback = append(s.feedback, q)
}
return nil
}
// tryToRemoveFromList will remove this collector from the list if it's deleted flag is set.
func (s *SessionStatsCollector) tryToRemoveFromList() {
s.Lock()
defer s.Unlock()
if !s.deleted {
return
}
next := s.next
prev := s.prev
prev.next = next
if next != nil {
next.prev = prev
}
}
// NewSessionStatsCollector allocates a stats collector for a session.
func (h *Handle) NewSessionStatsCollector() *SessionStatsCollector {
h.listHead.Lock()
defer h.listHead.Unlock()
newCollector := &SessionStatsCollector{
mapper: make(tableDeltaMap),
rateMap: make(errorRateDeltaMap),
next: h.listHead.next,
prev: h.listHead,
}
if h.listHead.next != nil {
h.listHead.next.prev = newCollector
}
h.listHead.next = newCollector
return newCollector
}
var (
// DumpStatsDeltaRatio is the lower bound of `Modify Count / Table Count` for stats delta to be dumped.
DumpStatsDeltaRatio = 1 / 10000.0
// dumpStatsMaxDuration is the max duration since last update.
dumpStatsMaxDuration = time.Hour
)
// needDumpStatsDelta returns true when only updates a small portion of the table and the time since last update
// do not exceed one hour.
func needDumpStatsDelta(h *Handle, id int64, item variable.TableDelta, currentTime time.Time) bool {
if item.InitTime.IsZero() {
item.InitTime = currentTime
}
tbl, ok := h.statsCache.Load().(statsCache)[id]
if !ok {
// No need to dump if the stats is invalid.
return false
}
if currentTime.Sub(item.InitTime) > dumpStatsMaxDuration {
// Dump the stats to kv at least once an hour.
return true
}
if tbl.Count == 0 || float64(item.Count)/float64(tbl.Count) > DumpStatsDeltaRatio {
// Dump the stats when there are many modifications.
return true
}
return false
}
const (
// DumpAll indicates dump all the delta info in to kv
DumpAll = true
// DumpDelta indicates dump part of the delta info in to kv.
DumpDelta = false
)
// DumpStatsDeltaToKV sweeps the whole list and updates the global map, then we dumps every table that held in map to KV.
// If the `dumpAll` is false, it will only dump that delta info that `Modify Count / Table Count` greater than a ratio.
func (h *Handle) DumpStatsDeltaToKV(dumpMode bool) error {
h.listHead.Lock()
for collector := h.listHead.next; collector != nil; collector = collector.next {
collector.tryToRemoveFromList()
h.merge(collector)
}
h.listHead.Unlock()
currentTime := time.Now()
for id, item := range h.globalMap {
if dumpMode == DumpDelta && !needDumpStatsDelta(h, id, item, currentTime) {
continue
}
updated, err := h.dumpTableStatCountToKV(id, item)
if err != nil {
return errors.Trace(err)
}
if updated {
h.globalMap.update(id, -item.Delta, -item.Count, nil)
}
if err = h.dumpTableStatColSizeToKV(id, item); err != nil {
return errors.Trace(err)
}
if updated {
delete(h.globalMap, id)
} else {
m := h.globalMap[id]
m.ColSize = nil
h.globalMap[id] = m
}
}
return nil
}
// dumpTableStatDeltaToKV dumps a single delta with some table to KV and updates the version.
func (h *Handle) dumpTableStatCountToKV(id int64, delta variable.TableDelta) (bool, error) {
if delta.Count == 0 {
return true, nil
}
ctx := context.TODO()
_, err := h.ctx.(sqlexec.SQLExecutor).Execute(ctx, "begin")
if err != nil {
return false, errors.Trace(err)
}
var sql string
if delta.Delta < 0 {
sql = fmt.Sprintf("update mysql.stats_meta set version = %d, count = count - %d, modify_count = modify_count + %d where table_id = %d and count >= %d", h.ctx.Txn().StartTS(), -delta.Delta, delta.Count, id, -delta.Delta)
} else {
sql = fmt.Sprintf("update mysql.stats_meta set version = %d, count = count + %d, modify_count = modify_count + %d where table_id = %d", h.ctx.Txn().StartTS(), delta.Delta, delta.Count, id)
}
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(ctx, sql)
if err != nil {
return false, errors.Trace(err)
}
updated := h.ctx.GetSessionVars().StmtCtx.AffectedRows() > 0
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(ctx, "commit")
return updated, errors.Trace(err)
}
func (h *Handle) dumpTableStatColSizeToKV(id int64, delta variable.TableDelta) error {
if len(delta.ColSize) == 0 {
return nil
}
ctx := context.TODO()
_, err := h.ctx.(sqlexec.SQLExecutor).Execute(ctx, "begin")
if err != nil {
return errors.Trace(err)
}
version := h.ctx.Txn().StartTS()
for key, val := range delta.ColSize {
if val == 0 {
continue
}
sql := fmt.Sprintf("update mysql.stats_histograms set version = %d, tot_col_size = tot_col_size + %d where hist_id = %d and table_id = %d and is_index = 0", version, val, key, id)
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(ctx, sql)
if err != nil {
return errors.Trace(err)
}
}
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(ctx, "commit")
return errors.Trace(err)
}
// DumpStatsFeedbackToKV dumps the stats feedback to KV.
func (h *Handle) DumpStatsFeedbackToKV() error {
var err error
var successCount int
for _, fb := range h.feedback {
err = h.dumpFeedbackToKV(fb)
if err != nil {
break
}
successCount++
}
h.feedback = h.feedback[successCount:]
return errors.Trace(err)
}
func (h *Handle) dumpFeedbackToKV(fb *QueryFeedback) error {
vals, err := encodeFeedback(fb)
if err != nil {
log.Debugf("error occurred when encoding feedback, err: ", errors.ErrorStack(err))
return nil
}
var isIndex int64
if fb.hist.tp.Tp == mysql.TypeBlob {
isIndex = 1
} else {
isIndex = 0
}
sql := fmt.Sprintf("insert into mysql.stats_feedback (table_id, hist_id, is_index, feedback) values "+
"(%d, %d, %d, X'%X')", fb.tableID, fb.hist.ID, isIndex, vals)
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(context.TODO(), sql)
if err != nil {
metrics.DumpFeedbackCounter.WithLabelValues(metrics.LblError).Inc()
} else {
metrics.DumpFeedbackCounter.WithLabelValues(metrics.LblOK).Inc()
}
return errors.Trace(err)
}
// UpdateErrorRate updates the error rate of columns from h.rateMap to cache.
func (h *Handle) UpdateErrorRate(is infoschema.InfoSchema) {
tbls := make([]*Table, 0, len(h.rateMap))
for id, item := range h.rateMap {
table, ok := is.TableByID(id)
if !ok {
continue
}
tbl := h.GetTableStats(table.Meta()).copy()
if item.PkErrorRate != nil && tbl.Columns[item.PkID] != nil {
col := *tbl.Columns[item.PkID]
col.ErrorRate.merge(item.PkErrorRate)
tbl.Columns[item.PkID] = &col
}
for key, val := range item.IdxErrorRate {
if tbl.Indices[key] == nil {
continue
}
idx := *tbl.Indices[key]
idx.ErrorRate.merge(val)
tbl.Indices[key] = &idx
}
tbls = append(tbls, tbl)
delete(h.rateMap, id)
}
h.UpdateTableStats(tbls, nil)
}
// HandleUpdateStats update the stats using feedback.
func (h *Handle) HandleUpdateStats(is infoschema.InfoSchema) error {
sql := "select table_id, hist_id, is_index, feedback from mysql.stats_feedback order by table_id, hist_id, is_index"
rows, _, err := h.ctx.(sqlexec.RestrictedSQLExecutor).ExecRestrictedSQL(h.ctx, sql)
if len(rows) == 0 || err != nil {
return errors.Trace(err)
}
tableID, histID, isIndex := int64(-1), int64(-1), int64(-1)
q := &QueryFeedback{}
var (
cms *CMSketch
hist *Histogram
col *Column
idx *Index
PKIsHandle bool
)
for _, row := range rows {
// merge into previous feedback
if row.GetInt64(0) == tableID && row.GetInt64(1) == histID && row.GetInt64(2) == isIndex {
err = decodeFeedback(row.GetBytes(3), q, cms)
if err != nil {
log.Debugf("decode feedback failed, err: %v", errors.ErrorStack(err))
}
continue
}
// dump the stats into kv
if hist != nil {
// Update the NDV of primary key column.
if col != nil && mysql.HasPriKeyFlag(col.Info.Flag) && PKIsHandle {
hist.NDV = int64(hist.totalRowCount())
col = nil
}
err = h.dumpStatsUpdateToKV(tableID, int(isIndex), q, hist, cms)
if err != nil {
return errors.Trace(err)
}
}
// initialize new feedback
tableID, histID, isIndex = row.GetInt64(0), row.GetInt64(1), row.GetInt64(2)
table, ok := is.TableByID(tableID)
if !ok {
hist, cms = nil, nil
continue
}
PKIsHandle = table.Meta().PKIsHandle
tbl := h.GetTableStats(table.Meta())
if isIndex == 1 {
idx, ok = tbl.Indices[histID]
if !ok {
hist, cms = nil, nil
continue
}
idxHist := idx.Histogram
hist = &idxHist
cms = idx.CMSketch.copy()
} else {
col, ok = tbl.Columns[histID]
if !ok {
hist, cms = nil, nil
continue
}
colHist := col.Histogram
hist = &colHist
cms = nil
}
err = decodeFeedback(row.GetBytes(3), q, cms)
if err != nil {
log.Debugf("decode feedback failed, err: %v", errors.ErrorStack(err))
}
}
// Update the NDV of primary key column.
if col != nil && mysql.HasPriKeyFlag(col.Info.Flag) && PKIsHandle {
hist.NDV = int64(hist.totalRowCount())
}
// dump the last feedback into kv
err = h.dumpStatsUpdateToKV(tableID, int(isIndex), q, hist, cms)
return errors.Trace(err)
}
func (h *Handle) dumpStatsUpdateToKV(tableID int64, isIndex int, q *QueryFeedback, hist *Histogram, cms *CMSketch) (err error) {
defer func() {
if err != nil {
metrics.UpdateStatsCounter.WithLabelValues(metrics.LblError).Inc()
} else {
metrics.UpdateStatsCounter.WithLabelValues(metrics.LblOK).Inc()
}
}()
hist = UpdateHistogram(hist, q)
err = SaveStatsToStorage(h.ctx, tableID, -1, isIndex, hist, cms, 0)
if err != nil {
return errors.Trace(err)
}
h.ctx.GetSessionVars().BatchDelete = true
sql := fmt.Sprintf("delete from mysql.stats_feedback where table_id = %d and hist_id = %d and is_index = %d", tableID, hist.ID, isIndex)
_, err = h.ctx.(sqlexec.SQLExecutor).Execute(context.TODO(), sql)
q.feedback = q.feedback[:0]
return errors.Trace(err)
}
const (
// StatsOwnerKey is the stats owner path that is saved to etcd.
StatsOwnerKey = "/tidb/stats/owner"
// StatsPrompt is the prompt for stats owner manager.
StatsPrompt = "stats"
)
// AutoAnalyzeMinCnt means if the count of table is less than this value, we needn't do auto analyze.
var AutoAnalyzeMinCnt int64 = 1000
func needAnalyzeTable(tbl *Table, limit time.Duration, autoAnalyzeRatio float64) bool {
if tbl.ModifyCount == 0 || tbl.Count < AutoAnalyzeMinCnt {
return false
}
t := time.Unix(0, oracle.ExtractPhysical(tbl.Version)*int64(time.Millisecond))
if time.Since(t) < limit {
return false
}
if autoAnalyzeRatio > 0 && float64(tbl.ModifyCount)/float64(tbl.Count) > autoAnalyzeRatio {
return true
}
for _, col := range tbl.Columns {
if col.Count > 0 {
return false
}
}
for _, idx := range tbl.Indices {
if idx.Len() > 0 {
return false
}
}
return true
}
const minAutoAnalyzeRatio = 0.3
func getAutoAnalyzeRatio(sctx sessionctx.Context) float64 {
sql := fmt.Sprintf("select variable_value from mysql.global_variables where variable_name = '%s'", variable.TiDBAutoAnalyzeRatio)
rows, _, err := sctx.(sqlexec.RestrictedSQLExecutor).ExecRestrictedSQL(sctx, sql)
if err != nil {
return variable.DefAutoAnalyzeRatio
}
autoAnalyzeRatio := variable.DefAutoAnalyzeRatio
if len(rows) > 0 {
autoAnalyzeRatio, err = strconv.ParseFloat(rows[0].GetString(0), 64)
if err != nil {
return variable.DefAutoAnalyzeRatio
}
}
if autoAnalyzeRatio > 0 {
autoAnalyzeRatio = math.Max(autoAnalyzeRatio, minAutoAnalyzeRatio)
}
return autoAnalyzeRatio
}
// HandleAutoAnalyze analyzes the newly created table or index.
func (h *Handle) HandleAutoAnalyze(is infoschema.InfoSchema) error {
dbs := is.AllSchemaNames()
autoAnalyzeRatio := getAutoAnalyzeRatio(h.ctx)
for _, db := range dbs {
tbls := is.SchemaTables(model.NewCIStr(db))
for _, tbl := range tbls {
tblInfo := tbl.Meta()
statsTbl := h.GetTableStats(tblInfo)
if statsTbl.Pseudo || statsTbl.Count == 0 {
continue
}
tblName := "`" + db + "`.`" + tblInfo.Name.O + "`"
if needAnalyzeTable(statsTbl, 20*h.Lease, autoAnalyzeRatio) {
sql := fmt.Sprintf("analyze table %s", tblName)
log.Infof("[stats] auto analyze table %s now", tblName)
return errors.Trace(h.execAutoAnalyze(sql))
}
for _, idx := range tblInfo.Indices {
if idx.State != model.StatePublic {
continue
}
if _, ok := statsTbl.Indices[idx.ID]; !ok {
sql := fmt.Sprintf("analyze table %s index `%s`", tblName, idx.Name.O)
log.Infof("[stats] auto analyze index `%s` for table %s now", idx.Name.O, tblName)
return errors.Trace(h.execAutoAnalyze(sql))
}
}
}
}
return nil
}
func (h *Handle) execAutoAnalyze(sql string) error {
startTime := time.Now()
_, _, err := h.ctx.(sqlexec.RestrictedSQLExecutor).ExecRestrictedSQL(h.ctx, sql)
metrics.AutoAnalyzeHistogram.Observe(time.Since(startTime).Seconds())
if err != nil {
metrics.AutoAnalyzeCounter.WithLabelValues("failed").Inc()
} else {
metrics.AutoAnalyzeCounter.WithLabelValues("succ").Inc()
}
return errors.Trace(err)
}