forked from vitessio/vitess
-
Notifications
You must be signed in to change notification settings - Fork 0
/
replication.go
395 lines (354 loc) · 12.3 KB
/
replication.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
// Copyright 2012, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
/*
Handle creating replicas and setting up the replication streams.
*/
package mysqlctl
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
log "github.com/golang/glog"
"golang.org/x/net/context"
"github.com/youtube/vitess/go/mysqlconn/replication"
"github.com/youtube/vitess/go/netutil"
"github.com/youtube/vitess/go/sqldb"
"github.com/youtube/vitess/go/vt/dbconfigs"
"github.com/youtube/vitess/go/vt/hook"
)
const (
// SQLStartSlave is the SQl command issued to start MySQL replication
SQLStartSlave = "START SLAVE"
// SQLStopSlave is the SQl command issued to stop MySQL replication
SQLStopSlave = "STOP SLAVE"
)
func changeMasterArgs(params *sqldb.ConnParams, masterHost string, masterPort int, masterConnectRetry int) []string {
var args []string
args = append(args, fmt.Sprintf("MASTER_HOST = '%s'", masterHost))
args = append(args, fmt.Sprintf("MASTER_PORT = %d", masterPort))
args = append(args, fmt.Sprintf("MASTER_USER = '%s'", params.Uname))
args = append(args, fmt.Sprintf("MASTER_PASSWORD = '%s'", params.Pass))
args = append(args, fmt.Sprintf("MASTER_CONNECT_RETRY = %d", masterConnectRetry))
if params.SslEnabled() {
args = append(args, "MASTER_SSL = 1")
}
if params.SslCa != "" {
args = append(args, fmt.Sprintf("MASTER_SSL_CA = '%s'", params.SslCa))
}
if params.SslCaPath != "" {
args = append(args, fmt.Sprintf("MASTER_SSL_CAPATH = '%s'", params.SslCaPath))
}
if params.SslCert != "" {
args = append(args, fmt.Sprintf("MASTER_SSL_CERT = '%s'", params.SslCert))
}
if params.SslKey != "" {
args = append(args, fmt.Sprintf("MASTER_SSL_KEY = '%s'", params.SslKey))
}
return args
}
// parseSlaveStatus parses the common fields of SHOW SLAVE STATUS.
func parseSlaveStatus(fields map[string]string) Status {
status := Status{
MasterHost: fields["Master_Host"],
SlaveIORunning: fields["Slave_IO_Running"] == "Yes",
SlaveSQLRunning: fields["Slave_SQL_Running"] == "Yes",
}
parseInt, _ := strconv.ParseInt(fields["Master_Port"], 10, 0)
status.MasterPort = int(parseInt)
parseInt, _ = strconv.ParseInt(fields["Connect_Retry"], 10, 0)
status.MasterConnectRetry = int(parseInt)
parseUint, _ := strconv.ParseUint(fields["Seconds_Behind_Master"], 10, 0)
status.SecondsBehindMaster = uint(parseUint)
return status
}
// WaitForSlaveStart waits until the deadline for replication to start.
// This validates the current master is correct and can be connected to.
func WaitForSlaveStart(mysqld MysqlDaemon, slaveStartDeadline int) error {
var rowMap map[string]string
for slaveWait := 0; slaveWait < slaveStartDeadline; slaveWait++ {
status, err := mysqld.SlaveStatus()
if err != nil {
return err
}
if status.SlaveRunning() {
return nil
}
time.Sleep(time.Second)
}
errorKeys := []string{"Last_Error", "Last_IO_Error", "Last_SQL_Error"}
errs := make([]string, 0, len(errorKeys))
for _, key := range errorKeys {
if rowMap[key] != "" {
errs = append(errs, key+": "+rowMap[key])
}
}
if len(errs) != 0 {
return errors.New(strings.Join(errs, ", "))
}
return nil
}
// StartSlave starts a slave on the provided MysqldDaemon
func StartSlave(md MysqlDaemon, hookExtraEnv map[string]string) error {
if err := md.ExecuteSuperQueryList(context.TODO(), []string{SQLStartSlave}); err != nil {
return err
}
h := hook.NewSimpleHook("postflight_start_slave")
h.ExtraEnv = hookExtraEnv
return h.ExecuteOptional()
}
// StopSlave stops a slave on the provided MysqldDaemon
func StopSlave(md MysqlDaemon, hookExtraEnv map[string]string) error {
h := hook.NewSimpleHook("preflight_stop_slave")
h.ExtraEnv = hookExtraEnv
if err := h.ExecuteOptional(); err != nil {
return err
}
return md.ExecuteSuperQueryList(context.TODO(), []string{SQLStopSlave})
}
// GetMysqlPort returns mysql port
func (mysqld *Mysqld) GetMysqlPort() (int32, error) {
qr, err := mysqld.FetchSuperQuery(context.TODO(), "SHOW VARIABLES LIKE 'port'")
if err != nil {
return 0, err
}
if len(qr.Rows) != 1 {
return 0, errors.New("no port variable in mysql")
}
utemp, err := strconv.ParseUint(qr.Rows[0][1].String(), 10, 16)
if err != nil {
return 0, err
}
return int32(utemp), nil
}
// IsReadOnly return true if the instance is read only
func (mysqld *Mysqld) IsReadOnly() (bool, error) {
qr, err := mysqld.FetchSuperQuery(context.TODO(), "SHOW VARIABLES LIKE 'read_only'")
if err != nil {
return true, err
}
if len(qr.Rows) != 1 {
return true, errors.New("no read_only variable in mysql")
}
if qr.Rows[0][1].String() == "ON" {
return true, nil
}
return false, nil
}
// SetReadOnly set/unset the read_only flag
func (mysqld *Mysqld) SetReadOnly(on bool) error {
query := "SET GLOBAL read_only = "
if on {
query += "ON"
} else {
query += "OFF"
}
return mysqld.ExecuteSuperQuery(context.TODO(), query)
}
var (
// ErrNotSlave means there is no slave status
ErrNotSlave = errors.New("no slave status")
// ErrNotMaster means there is no master status
ErrNotMaster = errors.New("no master status")
)
// WaitMasterPos lets slaves wait to given replication position
func (mysqld *Mysqld) WaitMasterPos(ctx context.Context, targetPos replication.Position) error {
flavor, err := mysqld.flavor()
if err != nil {
return fmt.Errorf("WaitMasterPos needs flavor: %v", err)
}
return flavor.WaitMasterPos(ctx, mysqld, targetPos)
}
// SlaveStatus returns the slave replication statuses
func (mysqld *Mysqld) SlaveStatus() (Status, error) {
flavor, err := mysqld.flavor()
if err != nil {
return Status{}, fmt.Errorf("SlaveStatus needs flavor: %v", err)
}
return flavor.SlaveStatus(mysqld)
}
// MasterPosition returns master replication position
func (mysqld *Mysqld) MasterPosition() (rp replication.Position, err error) {
flavor, err := mysqld.flavor()
if err != nil {
return rp, fmt.Errorf("MasterPosition needs flavor: %v", err)
}
return flavor.MasterPosition(mysqld)
}
// SetSlavePositionCommands returns the commands to set the
// replication position at which the slave will resume
// when it is later reparented with SetMasterCommands.
func (mysqld *Mysqld) SetSlavePositionCommands(pos replication.Position) ([]string, error) {
flavor, err := mysqld.flavor()
if err != nil {
return nil, fmt.Errorf("SetSlavePositionCommands needs flavor: %v", err)
}
return flavor.SetSlavePositionCommands(pos)
}
// SetMasterCommands returns the commands to run to make the provided
// host / port the master.
func (mysqld *Mysqld) SetMasterCommands(masterHost string, masterPort int) ([]string, error) {
flavor, err := mysqld.flavor()
if err != nil {
return nil, fmt.Errorf("SetMasterCommands needs flavor: %v", err)
}
params, err := dbconfigs.WithCredentials(&mysqld.dbcfgs.Repl)
if err != nil {
return nil, err
}
return flavor.SetMasterCommands(¶ms, masterHost, masterPort, int(masterConnectRetry.Seconds()))
}
// ResetReplicationCommands returns the commands to run to reset all
// replication for this host.
func (mysqld *Mysqld) ResetReplicationCommands() ([]string, error) {
flavor, err := mysqld.flavor()
if err != nil {
return nil, fmt.Errorf("ResetReplicationCommands needs flavor: %v", err)
}
return flavor.ResetReplicationCommands(), nil
}
// +------+---------+---------------------+------+-------------+------+----------------------------------------------------------------+------------------+
// | Id | User | Host | db | Command | Time | State | Info |
// +------+---------+---------------------+------+-------------+------+----------------------------------------------------------------+------------------+
// | 9792 | vt_repl | host:port | NULL | Binlog Dump | 54 | Has sent all binlog to slave; waiting for binlog to be updated | NULL |
// | 9797 | vt_dba | localhost | NULL | Query | 0 | NULL | show processlist |
// +------+---------+---------------------+------+-------------+------+----------------------------------------------------------------+------------------+
//
// Array indices for the results of SHOW PROCESSLIST.
const (
colConnectionID = iota
colUsername
colClientAddr
colDbName
colCommand
)
const (
// this is the command used by mysql slaves
binlogDumpCommand = "Binlog Dump"
)
// FindSlaves gets IP addresses for all currently connected slaves.
func FindSlaves(mysqld MysqlDaemon) ([]string, error) {
qr, err := mysqld.FetchSuperQuery(context.TODO(), "SHOW PROCESSLIST")
if err != nil {
return nil, err
}
addrs := make([]string, 0, 32)
for _, row := range qr.Rows {
// Check for prefix, since it could be "Binlog Dump GTID".
if strings.HasPrefix(row[colCommand].String(), binlogDumpCommand) {
host := row[colClientAddr].String()
if host == "localhost" {
// If we have a local binlog streamer, it will
// show up as being connected
// from 'localhost' through the local
// socket. Ignore it.
continue
}
host, _, err = netutil.SplitHostPort(host)
if err != nil {
return nil, fmt.Errorf("FindSlaves: malformed addr %v", err)
}
addrs = append(addrs, host)
}
}
return addrs, nil
}
// WaitBlpPosition will wait for the filtered replication to reach at least
// the provided position.
func WaitBlpPosition(ctx context.Context, mysqld MysqlDaemon, sql string, replicationPosition string) error {
position, err := replication.DecodePosition(replicationPosition)
if err != nil {
return err
}
for {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
qr, err := mysqld.FetchSuperQuery(ctx, sql)
if err != nil {
return err
}
if len(qr.Rows) != 1 {
return fmt.Errorf("QueryBlpCheckpoint(%v) returned unexpected row count: %v", sql, len(qr.Rows))
}
var pos replication.Position
if !qr.Rows[0][0].IsNull() {
pos, err = replication.DecodePosition(qr.Rows[0][0].String())
if err != nil {
return err
}
}
if pos.AtLeast(position) {
return nil
}
log.Infof("Sleeping 1 second waiting for binlog replication(%v) to catch up: %v != %v", sql, pos, position)
time.Sleep(1 * time.Second)
}
}
// EnableBinlogPlayback prepares the server to play back events from a binlog stream.
// Whatever it does for a given flavor, it must be idempotent.
func (mysqld *Mysqld) EnableBinlogPlayback() error {
flavor, err := mysqld.flavor()
if err != nil {
return fmt.Errorf("EnableBinlogPlayback needs flavor: %v", err)
}
return flavor.EnableBinlogPlayback(mysqld)
}
// DisableBinlogPlayback returns the server to the normal state after streaming.
// Whatever it does for a given flavor, it must be idempotent.
func (mysqld *Mysqld) DisableBinlogPlayback() error {
flavor, err := mysqld.flavor()
if err != nil {
return fmt.Errorf("DisableBinlogPlayback needs flavor: %v", err)
}
return flavor.DisableBinlogPlayback(mysqld)
}
// SetSemiSyncEnabled enables or disables semi-sync replication for
// master and/or slave mode.
func (mysqld *Mysqld) SetSemiSyncEnabled(master, slave bool) error {
log.Infof("Setting semi-sync mode: master=%v, slave=%v", master, slave)
// Convert bool to int.
var m, s int
if master {
m = 1
}
if slave {
s = 1
}
err := mysqld.ExecuteSuperQuery(context.TODO(), fmt.Sprintf(
"SET GLOBAL rpl_semi_sync_master_enabled = %v, GLOBAL rpl_semi_sync_slave_enabled = %v",
m, s))
if err != nil {
return fmt.Errorf("can't set semi-sync mode: %v; make sure plugins are loaded in my.cnf", err)
}
return nil
}
// SemiSyncEnabled returns whether semi-sync is enabled for master or slave.
// If the semi-sync plugin is not loaded, we assume semi-sync is disabled.
func (mysqld *Mysqld) SemiSyncEnabled() (master, slave bool) {
vars, err := mysqld.fetchVariables(context.TODO(), "rpl_semi_sync_%_enabled")
if err != nil {
return false, false
}
master = (vars["rpl_semi_sync_master_enabled"] == "ON")
slave = (vars["rpl_semi_sync_slave_enabled"] == "ON")
return master, slave
}
// SemiSyncSlaveStatus returns whether semi-sync is currently used by replication.
func (mysqld *Mysqld) SemiSyncSlaveStatus() (bool, error) {
qr, err := mysqld.FetchSuperQuery(context.TODO(), "SHOW STATUS LIKE 'rpl_semi_sync_slave_status'")
if err != nil {
return false, err
}
if len(qr.Rows) != 1 {
return false, errors.New("no rpl_semi_sync_slave_status variable in mysql")
}
if qr.Rows[0][1].String() == "ON" {
return true, nil
}
return false, nil
}