# # This test tests a potential race condition in MDL locking # --source include/galera_cluster.inc --source include/have_debug.inc --source include/have_debug_sync.inc --connection node_1 CREATE TABLE t1 (f1 INTEGER PRIMARY KEY, f2 CHAR(1)) engine=innodb; CREATE TABLE t2 (f1 INTEGER PRIMARY KEY, f2 CHAR(1)) engine=innodb; INSERT INTO t1 VALUES (1, 'a'); INSERT INTO t1 VALUES (2, 'a'); SET AUTOCOMMIT=ON; START TRANSACTION; UPDATE t1 SET f2 = 'b' WHERE f1 = 1; # block access to t2 --connect node_1a, 127.0.0.1, root, , test, $NODE_MYPORT_1 --connection node_1a SET SESSION wsrep_sync_wait=0; --let $wait_condition = SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 't2' --let $wait_condition_on_error_output = SELECT * FROM INFORMATION_SCHEMA.TABLES --source include/wait_condition_with_debug.inc LOCK TABLE t2 WRITE; # Block before MDL lock wait --connection node_1 SET DEBUG_SYNC= 'wsrep_before_mdl_wait SIGNAL before_mdl_wait WAIT_FOR mdl_wait_continue'; --send SELECT * FROM t2; --connection node_1a --echo # Wait until select is blocked before MDL lock wait SET DEBUG_SYNC= 'now WAIT_FOR before_mdl_wait'; # block applier to wait after BF victim is locked --connection node_1a SET @@debug_dbug = "d,sync.wsrep_after_BF_victim_lock"; # Issue a conflicting update on node #2 --connection node_2 UPDATE t1 SET f2 = 'c' WHERE f1 = 1; --connect node_1b, 127.0.0.1, root, , test, $NODE_MYPORT_1 --connection node_1b SET SESSION wsrep_sync_wait=0; --echo # Wait for conflicting update to block --let $wait_condition = SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE STATE LIKE 'Update_rows_log_event:%'; --source include/wait_condition.inc # Unblock the SELECT, to enter wsrep_thd_is_BF SET DEBUG_SYNC = "now SIGNAL signal.wsrep_after_BF_victim_lock"; --connect node_1c, 127.0.0.1, root, , test, $NODE_MYPORT_1 --connection node_1c --let $wait_condition = SELECT COUNT(*) = 0 FROM INFORMATION_SCHEMA.PROCESSLIST WHERE STATE LIKE 'Update_rows_log_event:%'; --source include/wait_condition.inc --connection node_1a # unblock applier to try to BF the SELECT SET DEBUG_SYNC = "now SIGNAL BF_victim_continue"; # table lock is not needed anymore UNLOCK TABLES; # SELECT returns deadlock --connection node_1 --error ER_LOCK_DEADLOCK --reap --connection node_1 SELECT COUNT(*) AS EXPECT_1 FROM t1 WHERE f2 = 'a'; SELECT COUNT(*) AS EXPECT_1 FROM t1 WHERE f2 = 'c'; SELECT * FROM t1; --connection node_2 SELECT COUNT(*) AS EXPECT_1 FROM t1 WHERE f2 = 'a'; SELECT COUNT(*) AS EXPECT_1 FROM t1 WHERE f2 = 'c'; SELECT * FROM t1; DROP TABLE t1; DROP TABLE t2; --connection node_1a SET DEBUG_SYNC = "RESET"; --connection node_1b SET DEBUG_SYNC = "RESET"; --connection node_1 --disconnect node_1a --disconnect node_1b --disconnect node_1c