// writeRecoveryPosition will write the current GTID as the recovery position
// for the next transaction.
// We will also try to get the timestamp for the transaction. Two cases:
// - we have statements, and they start with a SET TIMESTAMP that we
// can parse: then we update transaction_timestamp in blp_checkpoint
// with it, and set SecondsBehindMaster to now() - transaction_timestamp
// - otherwise (the statements are probably filtered out), we leave
// transaction_timestamp alone (keeping the old value), and we don't
// change SecondsBehindMaster
func (blp *BinlogPlayer) writeRecoveryPosition(tx *proto.BinlogTransaction) error {
now := time.Now().Unix()
blp.blpPos.Position = myproto.AppendGTID(blp.blpPos.Position, tx.GTIDField.Value)
updateRecovery := UpdateBlpCheckpoint(blp.blpPos.Uid, blp.blpPos.Position, now, tx.Timestamp)
qr, err := blp.exec(updateRecovery)
if err != nil {
return fmt.Errorf("Error %v in writing recovery info %v", err, updateRecovery)
}
if qr.RowsAffected != 1 {
return fmt.Errorf("Cannot update blp_recovery table, affected %v rows", qr.RowsAffected)
}
blp.blplStats.SetLastPosition(blp.blpPos.Position)
if tx.Timestamp != 0 {
blp.blplStats.SecondsBehindMaster.Set(now - tx.Timestamp)
}
return nil
}
// AppendGTID updates the current replication position by appending a GTID to
// the set of transactions that have been processed.
func (rci *RowcacheInvalidator) AppendGTID(gtid myproto.GTID) {
rci.posMutex.Lock()
defer rci.posMutex.Unlock()
rci.pos = myproto.AppendGTID(rci.pos, gtid)
}
// parseEvents processes the raw binlog dump stream from the server, one event
// at a time, and groups them into transactions. It is called from within the
// service function launched by Stream().
//
// If the sendTransaction func returns io.EOF, parseEvents returns ClientEOF.
// If the events channel is closed, parseEvents returns ServerEOF.
func (bls *BinlogStreamer) parseEvents(ctx *sync2.ServiceContext, events <-chan proto.BinlogEvent) (myproto.ReplicationPosition, error) {
var statements []proto.Statement
var format proto.BinlogFormat
var gtid myproto.GTID
var pos = bls.startPos
var autocommit = true
var err error
// A begin can be triggered either by a BEGIN query, or by a GTID_EVENT.
begin := func() {
if statements != nil {
// If this happened, it would be a legitimate error.
log.Errorf("BEGIN in binlog stream while still in another transaction; dropping %d statements: %v", len(statements), statements)
binlogStreamerErrors.Add("ParseEvents", 1)
}
statements = make([]proto.Statement, 0, 10)
autocommit = false
}
// A commit can be triggered either by a COMMIT query, or by an XID_EVENT.
// Statements that aren't wrapped in BEGIN/COMMIT are committed immediately.
commit := func(timestamp uint32) error {
trans := &proto.BinlogTransaction{
Statements: statements,
Timestamp: int64(timestamp),
GTIDField: myproto.GTIDField{Value: gtid},
}
if err = bls.sendTransaction(trans); err != nil {
if err == io.EOF {
return ClientEOF
}
return fmt.Errorf("send reply error: %v", err)
}
statements = nil
autocommit = true
return nil
}
// Parse events.
for ctx.IsRunning() {
var ev proto.BinlogEvent
var ok bool
select {
case ev, ok = <-events:
if !ok {
// events channel has been closed, which means the connection died.
log.Infof("reached end of binlog event stream")
return pos, ServerEOF
}
case <-ctx.ShuttingDown:
log.Infof("stopping early due to BinlogStreamer service shutdown")
return pos, nil
}
// Validate the buffer before reading fields from it.
if !ev.IsValid() {
return pos, fmt.Errorf("can't parse binlog event, invalid data: %#v", ev)
}
// We need to keep checking for FORMAT_DESCRIPTION_EVENT even after we've
// seen one, because another one might come along (e.g. on log rotate due to
// binlog settings change) that changes the format.
if ev.IsFormatDescription() {
format, err = ev.Format()
if err != nil {
return pos, fmt.Errorf("can't parse FORMAT_DESCRIPTION_EVENT: %v, event data: %#v", err, ev)
}
continue
}
// We can't parse anything until we get a FORMAT_DESCRIPTION_EVENT that
// tells us the size of the event header.
if format.IsZero() {
// The only thing that should come before the FORMAT_DESCRIPTION_EVENT
// is a fake ROTATE_EVENT, which the master sends to tell us the name
// of the current log file.
if ev.IsRotate() {
continue
}
return pos, fmt.Errorf("got a real event before FORMAT_DESCRIPTION_EVENT: %#v", ev)
}
// Strip the checksum, if any. We don't actually verify the checksum, so discard it.
ev, _ = ev.StripChecksum(format)
// Update the GTID if the event has one. The actual event type could be
// something special like GTID_EVENT (MariaDB, MySQL 5.6), or it could be
// an arbitrary event with a GTID in the header (Google MySQL).
if ev.HasGTID(format) {
gtid, err = ev.GTID(format)
if err != nil {
return pos, fmt.Errorf("can't get GTID from binlog event: %v, event data: %#v", err, ev)
}
pos = myproto.AppendGTID(pos, gtid)
}
switch {
case ev.IsGTID(): // GTID_EVENT
if ev.IsBeginGTID(format) {
begin()
}
case ev.IsXID(): // XID_EVENT (equivalent to COMMIT)
if err = commit(ev.Timestamp()); err != nil {
return pos, err
}
case ev.IsIntVar(): // INTVAR_EVENT
name, value, err := ev.IntVar(format)
if err != nil {
return pos, fmt.Errorf("can't parse INTVAR_EVENT: %v, event data: %#v", err, ev)
}
statements = append(statements, proto.Statement{
Category: proto.BL_SET,
Sql: []byte(fmt.Sprintf("SET %s=%d", name, value)),
})
case ev.IsRand(): // RAND_EVENT
seed1, seed2, err := ev.Rand(format)
if err != nil {
return pos, fmt.Errorf("can't parse RAND_EVENT: %v, event data: %#v", err, ev)
}
statements = append(statements, proto.Statement{
Category: proto.BL_SET,
Sql: []byte(fmt.Sprintf("SET @@RAND_SEED1=%d, @@RAND_SEED2=%d", seed1, seed2)),
})
case ev.IsQuery(): // QUERY_EVENT
// Extract the query string and group into transactions.
q, err := ev.Query(format)
if err != nil {
return pos, fmt.Errorf("can't get query from binlog event: %v, event data: %#v", err, ev)
}
switch cat := getStatementCategory(q.Sql); cat {
case proto.BL_BEGIN:
begin()
case proto.BL_ROLLBACK:
// Rollbacks are possible under some circumstances. Since the stream
// client keeps track of its replication position by updating the set
// of GTIDs it's seen, we must commit an empty transaction so the client
// can update its position.
statements = nil
fallthrough
case proto.BL_COMMIT:
if err = commit(ev.Timestamp()); err != nil {
return pos, err
}
default: // BL_DDL, BL_DML, BL_SET, BL_UNRECOGNIZED
if q.Database != "" && q.Database != bls.dbname {
// Skip cross-db statements.
continue
}
setTimestamp := proto.Statement{
Category: proto.BL_SET,
Sql: []byte(fmt.Sprintf("SET TIMESTAMP=%d", ev.Timestamp())),
}
statement := proto.Statement{Category: cat, Sql: q.Sql}
// If the statement has a charset and it's different than our client's
// default charset, send it along with the statement.
// If our client hasn't told us its charset, always send it.
if bls.clientCharset == nil || (q.Charset != nil && *q.Charset != *bls.clientCharset) {
setTimestamp.Charset = q.Charset
statement.Charset = q.Charset
}
statements = append(statements, setTimestamp, statement)
if autocommit {
if err = commit(ev.Timestamp()); err != nil {
return pos, err
}
}
}
}
}
return pos, nil
}