connection node_2;
connection node_1;
connection node_1;
CREATE TABLE t1 (f1 INTEGER) Engine=InnoDB;
SET GLOBAL wsrep_slave_threads = 10;
# Set slave threads to 10 step 1
SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_10
10
SET GLOBAL wsrep_slave_threads = 1;
connection node_2;
INSERT INTO t1 VALUES (1);
connection node_1;
# Wait until one of the appliers has exited
SELECT VARIABLE_VALUE AS EXPECT_9 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_9
9
SET GLOBAL wsrep_slave_threads = 10;
# Set slave threads to 10 step 2
SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_10
10
SET GLOBAL wsrep_slave_threads = 20;
# Set slave threads to 20
SELECT VARIABLE_VALUE AS EXPECT_20 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_20
20
SET GLOBAL wsrep_slave_threads = 1;
connection node_2;
INSERT INTO t1 VALUES (1);
INSERT INTO t1 VALUES (2);
INSERT INTO t1 VALUES (3);
INSERT INTO t1 VALUES (4);
INSERT INTO t1 VALUES (5);
INSERT INTO t1 VALUES (6);
INSERT INTO t1 VALUES (7);
INSERT INTO t1 VALUES (8);
INSERT INTO t1 VALUES (9);
INSERT INTO t1 VALUES (10);
INSERT INTO t1 VALUES (11);
INSERT INTO t1 VALUES (12);
INSERT INTO t1 VALUES (13);
INSERT INTO t1 VALUES (14);
INSERT INTO t1 VALUES (16);
INSERT INTO t1 VALUES (17);
INSERT INTO t1 VALUES (18);
INSERT INTO t1 VALUES (19);
INSERT INTO t1 VALUES (20);
connection node_1;
# Wait until 19 of the appliers has exited
SELECT VARIABLE_VALUE AS EXPECT_1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_1
1
SELECT COUNT(*) FROM t1;
COUNT(*)
20
SET GLOBAL wsrep_slave_threads = 10;
# Set slave threads to 10 step 3
SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_10
10
connection node_1;
SET GLOBAL wsrep_slave_threads = 1;
connection node_2;
INSERT INTO t1 VALUES (21);
INSERT INTO t1 VALUES (22);
INSERT INTO t1 VALUES (23);
INSERT INTO t1 VALUES (24);
INSERT INTO t1 VALUES (25);
INSERT INTO t1 VALUES (26);
INSERT INTO t1 VALUES (27);
INSERT INTO t1 VALUES (28);
INSERT INTO t1 VALUES (29);
INSERT INTO t1 VALUES (30);
connection node_1;
# Wait until slave threads back to 1
SELECT VARIABLE_VALUE AS EXPECT_1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
EXPECT_1
1
SELECT COUNT(*) FROM t1;
COUNT(*)
30
DROP TABLE t1;