connection node_1; CREATE TABLE t1 (f1 INT PRIMARY KEY) Engine=InnoDB; CREATE TABLE t2 (f1 INT AUTO_INCREMENT PRIMARY KEY) Engine=InnoDB; connection node_2; CALL mtr.add_suppression("WSREP: Refusing exit for the last slave thread."); SET GLOBAL wsrep_slave_threads = 0; Warnings: Warning 1292 Truncated incorrect wsrep_slave_threads value: '0' SHOW WARNINGS; Level Code Message Warning 1292 Truncated incorrect wsrep_slave_threads value: '0' SELECT @@wsrep_slave_threads = 1; @@wsrep_slave_threads = 1 1 SET GLOBAL wsrep_slave_threads = 1; SELECT COUNT(*) FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE LIKE '%wsrep aborter%'; COUNT(*) 1 connection node_1; INSERT INTO t1 VALUES (1); connection node_2; SELECT COUNT(*) FROM t1; COUNT(*) 1 SET GLOBAL wsrep_slave_threads = 64; SET GLOBAL wsrep_slave_threads = 1; connection node_1; connection node_2; SELECT COUNT(*) FROM t2; COUNT(*) 70 SET GLOBAL wsrep_slave_threads = 1; DROP TABLE t1; DROP TABLE t2; # # lp:1372840 - Changing wsrep_slave_threads causes future connections to hang # connection node_1; CREATE TABLE t1 (i INT AUTO_INCREMENT PRIMARY KEY) ENGINE=INNODB; connection node_2; SET GLOBAL wsrep_slave_threads = 4; SET GLOBAL wsrep_slave_threads = 1; connection node_1; INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); INSERT INTO t1 VALUES (DEFAULT); DROP TABLE t1; connection node_2; SELECT NAME FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME LIKE 'test/t%'; NAME