Ejemplo n.º 1
0
// 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
}
Ejemplo n.º 2
0
// 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)
}
Ejemplo n.º 3
0
// 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
}