connect  slave,127.0.0.1,root,,,$SERVER_MYPORT_3;
change master 'master1' to 
master_port=MYPORT_1, 
master_host='127.0.0.1', 
master_user='root';
start slave 'master1';
set default_master_connection = 'master1';
include/wait_for_slave_to_start.inc
connect  master1,127.0.0.1,root,,,$SERVER_MYPORT_1;
drop table if exists t1;
create table t1 (i int) engine=MyISAM;
connection slave;
mysqld-relay-bin-master1.000001
mysqld-relay-bin-master1.000002
mysqld-relay-bin-master1.index
include/show_events.inc
Log_name	Pos	Event_type	Server_id	End_log_pos	Info
mysqld-relay-bin-master1.000002	#	Format_desc	#	#	SERVER_VERSION, BINLOG_VERSION
mysqld-relay-bin-master1.000002	#	Rotate	#	#	master-bin.000001;pos=POS
mysqld-relay-bin-master1.000002	#	Format_desc	#	#	SERVER_VERSION, BINLOG_VERSION
mysqld-relay-bin-master1.000002	#	Gtid_list	#	#	[]
mysqld-relay-bin-master1.000002	#	Binlog_checkpoint	#	#	master-bin.000001
mysqld-relay-bin-master1.000002	#	Gtid	#	#	GTID #-#-#
mysqld-relay-bin-master1.000002	#	Query	#	#	use `test`; DROP TABLE IF EXISTS `t1` /* generated by server */
mysqld-relay-bin-master1.000002	#	Gtid	#	#	GTID #-#-#
mysqld-relay-bin-master1.000002	#	Query	#	#	use `test`; create table t1 (i int) engine=MyISAM
include/show_events.inc
Log_name	Pos	Event_type	Server_id	End_log_pos	Info
mysqld-relay-bin-master1.000001	#	Format_desc	#	#	SERVER_VERSION, BINLOG_VERSION
mysqld-relay-bin-master1.000001	#	Rotate	#	#	mysqld-relay-bin-master1.000002;pos=4
connection master1;
drop table t1;
connection slave;
include/reset_master_slave.inc
disconnect slave;
connection master1;
include/reset_master_slave.inc
disconnect master1;