MDEV-21667 : Galera test failure on MW-336

Problem seems to be the fact that we did not enforce correct
applier thread numbers after every command that effects them.
Test changes only.

mysql-test/suite/galera/r/MW-336.result

@@ -2,14 +2,27 @@ 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);
@@ -22,28 +35,47 @@ INSERT INTO t1 VALUES (7);
 INSERT INTO t1 VALUES (8);
 INSERT INTO t1 VALUES (9);
 INSERT INTO t1 VALUES (10);
-connection node_1;
-SET GLOBAL wsrep_slave_threads = 10;
-SELECT COUNT(*) FROM t1;
-COUNT(*)
-11
-# Set slave threads to 10 step 3
-connection node_2;
 INSERT INTO t1 VALUES (11);
 INSERT INTO t1 VALUES (12);
 INSERT INTO t1 VALUES (13);
 INSERT INTO t1 VALUES (14);
-INSERT INTO t1 VALUES (15);
 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(*)
-23
-SET GLOBAL wsrep_slave_threads = 1;
+30
 DROP TABLE t1;

mysql-test/suite/galera/t/MW-336.test

@@ -17,20 +17,31 @@ SET GLOBAL wsrep_slave_threads = 10;
 --let $wait_condition_on_error_output = SELECT COUNT(*), 10 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
 --source include/wait_condition_with_debug.inc
 
+SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
 SET GLOBAL wsrep_slave_threads = 1;
 
 --connection node_2
 INSERT INTO t1 VALUES (1);
 
 --connection node_1
+--echo # Wait until one of the appliers has exited
+--let $wait_condition = SELECT VARIABLE_VALUE = 9 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+--let $wait_condition_on_error_output = SELECT COUNT(*), 9 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
+--source include/wait_condition_with_debug.inc
+
+SELECT VARIABLE_VALUE AS EXPECT_9 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
 SET GLOBAL wsrep_slave_threads = 10;
 
 # Note that above insert could be handled by one of the slave threads
 --echo # Set slave threads to 10 step 2
---let $wait_condition = SELECT VARIABLE_VALUE >= 9 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
---let $wait_condition_on_error_output = SELECT COUNT(*), 9 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
+--let $wait_condition = SELECT VARIABLE_VALUE = 10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+--let $wait_condition_on_error_output = SELECT COUNT(*), 10 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
 --source include/wait_condition_with_debug.inc
 
+SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
 SET GLOBAL wsrep_slave_threads = 20;
 
 --echo # Set slave threads to 20
@@ -38,6 +49,8 @@ SET GLOBAL wsrep_slave_threads = 20;
 --let $wait_condition_on_error_output = SELECT COUNT(*), 20 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
 --source include/wait_condition_with_debug.inc
 
+SELECT VARIABLE_VALUE AS EXPECT_20 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
 SET GLOBAL wsrep_slave_threads = 1;
 
 --connection node_2
@@ -51,30 +64,57 @@ INSERT INTO t1 VALUES (7);
 INSERT INTO t1 VALUES (8);
 INSERT INTO t1 VALUES (9);
 INSERT INTO t1 VALUES (10);
-
---connection node_1
-SET GLOBAL wsrep_slave_threads = 10;
-SELECT COUNT(*) FROM t1;
---echo # Set slave threads to 10 step 3
---let $wait_condition = SELECT VARIABLE_VALUE = 10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
---let $wait_condition_on_error_output = SELECT COUNT(*), 10 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
---source include/wait_condition_with_debug.inc
-
---connection node_2
 INSERT INTO t1 VALUES (11);
 INSERT INTO t1 VALUES (12);
 INSERT INTO t1 VALUES (13);
 INSERT INTO t1 VALUES (14);
-INSERT INTO t1 VALUES (15);
 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
+--echo # Wait until 19 of the appliers has exited
+--let $wait_condition = SELECT VARIABLE_VALUE = 1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+--let $wait_condition_on_error_output = SELECT COUNT(*), 1 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
+--source include/wait_condition_with_debug.inc
+
+SELECT VARIABLE_VALUE AS EXPECT_1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
+SELECT COUNT(*) FROM t1;
+
+SET GLOBAL wsrep_slave_threads = 10;
+--echo # Set slave threads to 10 step 3
+--let $wait_condition = SELECT VARIABLE_VALUE = 10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+--let $wait_condition_on_error_output = SELECT COUNT(*), 10 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
+--source include/wait_condition_with_debug.inc
+
+SELECT VARIABLE_VALUE AS EXPECT_10 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
+--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
+--echo # Wait until slave threads back to 1
+--let $wait_condition = SELECT VARIABLE_VALUE = 1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+--let $wait_condition_on_error_output = SELECT COUNT(*), 1 as EXPECTED_VALUE FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE = 'wsrep applier idle'; show processlist
+--source include/wait_condition_with_debug.inc
+
+SELECT VARIABLE_VALUE AS EXPECT_1 FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_applier_thread_count';
+
 SELECT COUNT(*) FROM t1;
-SET GLOBAL wsrep_slave_threads = 1;
+
 DROP TABLE t1;