gh-ost/vendor/github.com/siddontang/go-mysql/replication/binlogsyncer.go
2018-04-11 09:11:27 +03:00

596 lines
13 KiB
Go

package replication
import (
"crypto/tls"
"encoding/binary"
"fmt"
"os"
"sync"
"time"
"golang.org/x/net/context"
"github.com/juju/errors"
"github.com/ngaut/log"
"github.com/siddontang/go-mysql/client"
. "github.com/siddontang/go-mysql/mysql"
)
var (
errSyncRunning = errors.New("Sync is running, must Close first")
)
// BinlogSyncerConfig is the configuration for BinlogSyncer.
type BinlogSyncerConfig struct {
// ServerID is the unique ID in cluster.
ServerID uint32
// Flavor is "mysql" or "mariadb", if not set, use "mysql" default.
Flavor string
// Host is for MySQL server host.
Host string
// Port is for MySQL server port.
Port uint16
// User is for MySQL user.
User string
// Password is for MySQL password.
Password string
// Localhost is local hostname if register salve.
// If not set, use os.Hostname() instead.
Localhost string
// SemiSyncEnabled enables semi-sync or not.
SemiSyncEnabled bool
// RawModeEnabled is for not parsing binlog event.
RawModeEnabled bool
// If not nil, use the provided tls.Config to connect to the database using TLS/SSL.
TLSConfig *tls.Config
}
// BinlogSyncer syncs binlog event from server.
type BinlogSyncer struct {
m sync.RWMutex
cfg BinlogSyncerConfig
c *client.Conn
wg sync.WaitGroup
parser *BinlogParser
nextPos Position
running bool
ctx context.Context
cancel context.CancelFunc
}
// NewBinlogSyncer creates the BinlogSyncer with cfg.
func NewBinlogSyncer(cfg BinlogSyncerConfig) *BinlogSyncer {
// Clear the Password to avoid outputing it in log.
pass := cfg.Password
cfg.Password = ""
log.Infof("create BinlogSyncer with config %v", cfg)
cfg.Password = pass
b := new(BinlogSyncer)
b.cfg = cfg
b.parser = NewBinlogParser()
b.parser.SetRawMode(b.cfg.RawModeEnabled)
b.running = false
b.ctx, b.cancel = context.WithCancel(context.Background())
return b
}
// Close closes the BinlogSyncer.
func (b *BinlogSyncer) Close() {
b.m.Lock()
defer b.m.Unlock()
b.close()
}
func (b *BinlogSyncer) close() {
if b.isClosed() {
return
}
log.Info("syncer is closing...")
b.running = false
b.cancel()
if b.c != nil {
b.c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
}
b.wg.Wait()
if b.c != nil {
b.c.Close()
}
log.Info("syncer is closed")
}
func (b *BinlogSyncer) isClosed() bool {
select {
case <-b.ctx.Done():
return true
default:
return false
}
}
func (b *BinlogSyncer) registerSlave() error {
if b.c != nil {
b.c.Close()
}
log.Infof("register slave for master server %s:%d", b.cfg.Host, b.cfg.Port)
var err error
b.c, err = client.Connect(fmt.Sprintf("%s:%d", b.cfg.Host, b.cfg.Port), b.cfg.User, b.cfg.Password, "", func(c *client.Conn) {
c.TLSConfig = b.cfg.TLSConfig
})
if err != nil {
return errors.Trace(err)
}
//for mysql 5.6+, binlog has a crc32 checksum
//before mysql 5.6, this will not work, don't matter.:-)
if r, err := b.c.Execute("SHOW GLOBAL VARIABLES LIKE 'BINLOG_CHECKSUM'"); err != nil {
return errors.Trace(err)
} else {
s, _ := r.GetString(0, 1)
if s != "" {
// maybe CRC32 or NONE
// mysqlbinlog.cc use NONE, see its below comments:
// Make a notice to the server that this client
// is checksum-aware. It does not need the first fake Rotate
// necessary checksummed.
// That preference is specified below.
if _, err = b.c.Execute(`SET @master_binlog_checksum='NONE'`); err != nil {
return errors.Trace(err)
}
// if _, err = b.c.Execute(`SET @master_binlog_checksum=@@global.binlog_checksum`); err != nil {
// return errors.Trace(err)
// }
}
}
if b.cfg.Flavor == MariaDBFlavor {
// Refer https://github.com/alibaba/canal/wiki/BinlogChange(MariaDB5&10)
// Tell the server that we understand GTIDs by setting our slave capability
// to MARIA_SLAVE_CAPABILITY_GTID = 4 (MariaDB >= 10.0.1).
if _, err := b.c.Execute("SET @mariadb_slave_capability=4"); err != nil {
return errors.Errorf("failed to set @mariadb_slave_capability=4: %v", err)
}
}
if err = b.writeRegisterSlaveCommand(); err != nil {
return errors.Trace(err)
}
if _, err = b.c.ReadOKPacket(); err != nil {
return errors.Trace(err)
}
return nil
}
func (b *BinlogSyncer) enalbeSemiSync() error {
if !b.cfg.SemiSyncEnabled {
return nil
}
if r, err := b.c.Execute("SHOW VARIABLES LIKE 'rpl_semi_sync_master_enabled';"); err != nil {
return errors.Trace(err)
} else {
s, _ := r.GetString(0, 1)
if s != "ON" {
log.Errorf("master does not support semi synchronous replication, use no semi-sync")
b.cfg.SemiSyncEnabled = false
return nil
}
}
_, err := b.c.Execute(`SET @rpl_semi_sync_slave = 1;`)
if err != nil {
return errors.Trace(err)
}
return nil
}
func (b *BinlogSyncer) prepare() error {
if b.isClosed() {
return errors.Trace(ErrSyncClosed)
}
if err := b.registerSlave(); err != nil {
return errors.Trace(err)
}
if err := b.enalbeSemiSync(); err != nil {
return errors.Trace(err)
}
return nil
}
func (b *BinlogSyncer) startDumpStream() *BinlogStreamer {
b.running = true
s := newBinlogStreamer()
b.wg.Add(1)
go b.onStream(s)
return s
}
// StartSync starts syncing from the `pos` position.
func (b *BinlogSyncer) StartSync(pos Position) (*BinlogStreamer, error) {
log.Infof("begin to sync binlog from position %s", pos)
b.m.Lock()
defer b.m.Unlock()
if b.running {
return nil, errors.Trace(errSyncRunning)
}
if err := b.prepareSyncPos(pos); err != nil {
return nil, errors.Trace(err)
}
return b.startDumpStream(), nil
}
// StartSyncGTID starts syncing from the `gset` GTIDSet.
func (b *BinlogSyncer) StartSyncGTID(gset GTIDSet) (*BinlogStreamer, error) {
log.Infof("begin to sync binlog from GTID %s", gset)
b.m.Lock()
defer b.m.Unlock()
if b.running {
return nil, errors.Trace(errSyncRunning)
}
if err := b.prepare(); err != nil {
return nil, errors.Trace(err)
}
var err error
if b.cfg.Flavor != MariaDBFlavor {
// default use MySQL
err = b.writeBinlogDumpMysqlGTIDCommand(gset)
} else {
err = b.writeBinlogDumpMariadbGTIDCommand(gset)
}
if err != nil {
return nil, err
}
return b.startDumpStream(), nil
}
func (b *BinlogSyncer) writeBinglogDumpCommand(p Position) error {
b.c.ResetSequence()
data := make([]byte, 4+1+4+2+4+len(p.Name))
pos := 4
data[pos] = COM_BINLOG_DUMP
pos++
binary.LittleEndian.PutUint32(data[pos:], p.Pos)
pos += 4
binary.LittleEndian.PutUint16(data[pos:], BINLOG_DUMP_NEVER_STOP)
pos += 2
binary.LittleEndian.PutUint32(data[pos:], b.cfg.ServerID)
pos += 4
copy(data[pos:], p.Name)
return b.c.WritePacket(data)
}
func (b *BinlogSyncer) writeBinlogDumpMysqlGTIDCommand(gset GTIDSet) error {
p := Position{"", 4}
gtidData := gset.Encode()
b.c.ResetSequence()
data := make([]byte, 4+1+2+4+4+len(p.Name)+8+4+len(gtidData))
pos := 4
data[pos] = COM_BINLOG_DUMP_GTID
pos++
binary.LittleEndian.PutUint16(data[pos:], 0)
pos += 2
binary.LittleEndian.PutUint32(data[pos:], b.cfg.ServerID)
pos += 4
binary.LittleEndian.PutUint32(data[pos:], uint32(len(p.Name)))
pos += 4
n := copy(data[pos:], p.Name)
pos += n
binary.LittleEndian.PutUint64(data[pos:], uint64(p.Pos))
pos += 8
binary.LittleEndian.PutUint32(data[pos:], uint32(len(gtidData)))
pos += 4
n = copy(data[pos:], gtidData)
pos += n
data = data[0:pos]
return b.c.WritePacket(data)
}
func (b *BinlogSyncer) writeBinlogDumpMariadbGTIDCommand(gset GTIDSet) error {
// Copy from vitess
startPos := gset.String()
// Set the slave_connect_state variable before issuing COM_BINLOG_DUMP to
// provide the start position in GTID form.
query := fmt.Sprintf("SET @slave_connect_state='%s'", startPos)
if _, err := b.c.Execute(query); err != nil {
return errors.Errorf("failed to set @slave_connect_state='%s': %v", startPos, err)
}
// Real slaves set this upon connecting if their gtid_strict_mode option was
// enabled. We always use gtid_strict_mode because we need it to make our
// internal GTID comparisons safe.
if _, err := b.c.Execute("SET @slave_gtid_strict_mode=1"); err != nil {
return errors.Errorf("failed to set @slave_gtid_strict_mode=1: %v", err)
}
// Since we use @slave_connect_state, the file and position here are ignored.
return b.writeBinglogDumpCommand(Position{"", 0})
}
// localHostname returns the hostname that register slave would register as.
func (b *BinlogSyncer) localHostname() string {
if len(b.cfg.Localhost) == 0 {
h, _ := os.Hostname()
return h
}
return b.cfg.Localhost
}
func (b *BinlogSyncer) writeRegisterSlaveCommand() error {
b.c.ResetSequence()
hostname := b.localHostname()
// This should be the name of slave host not the host we are connecting to.
data := make([]byte, 4+1+4+1+len(hostname)+1+len(b.cfg.User)+1+len(b.cfg.Password)+2+4+4)
pos := 4
data[pos] = COM_REGISTER_SLAVE
pos++
binary.LittleEndian.PutUint32(data[pos:], b.cfg.ServerID)
pos += 4
// This should be the name of slave hostname not the host we are connecting to.
data[pos] = uint8(len(hostname))
pos++
n := copy(data[pos:], hostname)
pos += n
data[pos] = uint8(len(b.cfg.User))
pos++
n = copy(data[pos:], b.cfg.User)
pos += n
data[pos] = uint8(len(b.cfg.Password))
pos++
n = copy(data[pos:], b.cfg.Password)
pos += n
binary.LittleEndian.PutUint16(data[pos:], b.cfg.Port)
pos += 2
//replication rank, not used
binary.LittleEndian.PutUint32(data[pos:], 0)
pos += 4
// master ID, 0 is OK
binary.LittleEndian.PutUint32(data[pos:], 0)
return b.c.WritePacket(data)
}
func (b *BinlogSyncer) replySemiSyncACK(p Position) error {
b.c.ResetSequence()
data := make([]byte, 4+1+8+len(p.Name))
pos := 4
// semi sync indicator
data[pos] = SemiSyncIndicator
pos++
binary.LittleEndian.PutUint64(data[pos:], uint64(p.Pos))
pos += 8
copy(data[pos:], p.Name)
err := b.c.WritePacket(data)
if err != nil {
return errors.Trace(err)
}
_, err = b.c.ReadOKPacket()
if err != nil {
}
return errors.Trace(err)
}
func (b *BinlogSyncer) retrySync() error {
b.m.Lock()
defer b.m.Unlock()
log.Infof("begin to re-sync from %s", b.nextPos)
b.parser.Reset()
if err := b.prepareSyncPos(b.nextPos); err != nil {
return errors.Trace(err)
}
return nil
}
func (b *BinlogSyncer) prepareSyncPos(pos Position) error {
// always start from position 4
if pos.Pos < 4 {
pos.Pos = 4
}
if err := b.prepare(); err != nil {
return errors.Trace(err)
}
if err := b.writeBinglogDumpCommand(pos); err != nil {
return errors.Trace(err)
}
return nil
}
func (b *BinlogSyncer) onStream(s *BinlogStreamer) {
defer func() {
if e := recover(); e != nil {
s.closeWithError(fmt.Errorf("Err: %v\n Stack: %s", e, Pstack()))
}
b.wg.Done()
}()
for {
data, err := b.c.ReadPacket()
if err != nil {
log.Error(err)
// we meet connection error, should re-connect again with
// last nextPos we got.
if len(b.nextPos.Name) == 0 {
// we can't get the correct position, close.
s.closeWithError(err)
return
}
// TODO: add a max retry count.
for {
select {
case <-b.ctx.Done():
s.close()
return
case <-time.After(time.Second):
if err = b.retrySync(); err != nil {
log.Errorf("retry sync err: %v, wait 1s and retry again", err)
continue
}
}
break
}
// we connect the server and begin to re-sync again.
continue
}
switch data[0] {
case OK_HEADER:
if err = b.parseEvent(s, data); err != nil {
s.closeWithError(err)
return
}
case ERR_HEADER:
err = b.c.HandleErrorPacket(data)
s.closeWithError(err)
return
case EOF_HEADER:
// Refer http://dev.mysql.com/doc/internals/en/packet-EOF_Packet.html
// In the MySQL client/server protocol, EOF and OK packets serve the same purpose.
// Some users told me that they received EOF packet here, but I don't know why.
// So we only log a message and retry ReadPacket.
log.Info("receive EOF packet, retry ReadPacket")
continue
default:
log.Errorf("invalid stream header %c", data[0])
continue
}
}
}
func (b *BinlogSyncer) parseEvent(s *BinlogStreamer, data []byte) error {
//skip OK byte, 0x00
data = data[1:]
needACK := false
if b.cfg.SemiSyncEnabled && (data[0] == SemiSyncIndicator) {
needACK = (data[1] == 0x01)
//skip semi sync header
data = data[2:]
}
e, err := b.parser.parse(data)
if err != nil {
return errors.Trace(err)
}
if e.Header.LogPos > 0 {
// Some events like FormatDescriptionEvent return 0, ignore.
b.nextPos.Pos = e.Header.LogPos
}
if re, ok := e.Event.(*RotateEvent); ok {
b.nextPos.Name = string(re.NextLogName)
b.nextPos.Pos = uint32(re.Position)
log.Infof("rotate to %s", b.nextPos)
}
needStop := false
select {
case s.ch <- e:
case <-b.ctx.Done():
needStop = true
}
if needACK {
err := b.replySemiSyncACK(b.nextPos)
if err != nil {
return errors.Trace(err)
}
}
if needStop {
return errors.New("sync is been closing...")
}
return nil
}