--echo ***MDEV-5914: Parallel replication deadlock due to InnoDB lock conflicts *** --source include/have_innodb.inc --source include/have_debug.inc --source include/have_debug_sync.inc --source include/master-slave.inc --connection server_2 SET sql_log_bin=0; CALL mtr.add_suppression("Commit failed due to failure of an earlier commit on which this one depends"); SET sql_log_bin=1; SET @old_parallel_threads=@@GLOBAL.slave_parallel_threads; --source include/stop_slave.inc SET GLOBAL slave_parallel_threads=10; CHANGE MASTER TO master_use_gtid=slave_pos; --connection server_1 ALTER TABLE mysql.gtid_slave_pos ENGINE=InnoDB; CREATE TABLE t4 (a INT PRIMARY KEY, b INT, KEY b_idx(b)) ENGINE=InnoDB; INSERT INTO t4 VALUES (1,NULL), (2,2), (3,NULL), (4,4), (5, NULL), (6, 6); --connect (con1,127.0.0.1,root,,test,$SERVER_MYPORT_1,) --connect (con2,127.0.0.1,root,,test,$SERVER_MYPORT_1,) # Create a group commit with UPDATE and DELETE, in that order. # The bug was that while the UPDATE's row lock does not block the DELETE, the # DELETE's gap lock _does_ block the UPDATE. This could cause a deadlock # on the slave. --connection con1 SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued1 WAIT_FOR master_cont1'; send UPDATE t4 SET b=NULL WHERE a=6; --connection server_1 SET debug_sync='now WAIT_FOR master_queued1'; --connection con2 SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued2'; send DELETE FROM t4 WHERE b <= 3; --connection server_1 SET debug_sync='now WAIT_FOR master_queued2'; SET debug_sync='now SIGNAL master_cont1'; --connection con1 REAP; --connection con2 REAP; SET debug_sync='RESET'; --save_master_pos --connection server_2 --source include/start_slave.inc --sync_with_master --source include/stop_slave.inc SELECT * FROM t4 ORDER BY a; # Another example, this one with INSERT vs. DELETE --connection server_1 DELETE FROM t4; INSERT INTO t4 VALUES (1,NULL), (2,2), (3,NULL), (4,4), (5, NULL), (6, 6); # Create a group commit with INSERT and DELETE, in that order. # The bug was that while the INSERT's insert intention lock does not block # the DELETE, the DELETE's gap lock _does_ block the INSERT. This could cause # a deadlock on the slave. --connection con1 SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued1 WAIT_FOR master_cont1'; send INSERT INTO t4 VALUES (7, NULL); --connection server_1 SET debug_sync='now WAIT_FOR master_queued1'; --connection con2 SET debug_sync='commit_after_release_LOCK_prepare_ordered SIGNAL master_queued2'; send DELETE FROM t4 WHERE b <= 3; --connection server_1 SET debug_sync='now WAIT_FOR master_queued2'; SET debug_sync='now SIGNAL master_cont1'; --connection con1 REAP; --connection con2 REAP; SET debug_sync='RESET'; --save_master_pos --connection server_2 --source include/start_slave.inc --sync_with_master --source include/stop_slave.inc SELECT * FROM t4 ORDER BY a; # Clean up. --connection server_2 SET GLOBAL slave_parallel_threads=@old_parallel_threads; --source include/start_slave.inc SET DEBUG_SYNC= 'RESET'; --connection server_1 --disconnect con1 --disconnect con2 DROP TABLE t4; SET DEBUG_SYNC= 'RESET'; --source include/rpl_end.inc