# --source include/have_debug_sync.inc --source include/not_embedded.inc # Save the initial number of concurrent sessions. --source include/count_sessions.inc --echo # --echo # Bug#18591145 - SOME MONOTONICALLY INCREASING STATUS VARIABLES DECREASES UNEXPECTEDLY --echo # --enable_connect_log show variables like "show_COMPATIBILITY_56"; let $compatibility_mode=`select @@global.show_compatibility_56`; # Information Schema will work only server is running in 5.6 compatiability # mode. Else information_schema will return empty set. set global SHOW_COMPATIBILITY_56 = 1; CREATE TABLE t1 (id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(64), val VARCHAR(1024)); --echo # Insert 1 tuple to increment com_insert status. INSERT INTO t1(name, val) VALUES ('dummy', 0); connect (con1, localhost, root,,); SET DEBUG_SYNC='before_preparing_global_status_array SIGNAL change_user WAIT_FOR continue'; SET DEBUG_SYNC='after_preparing_global_status_array SIGNAL continue_change_user'; --SEND INSERT INTO t1(name, val) SELECT * FROM INFORMATION_SCHEMA.global_status WHERE variable_name='com_insert'; CONNECTION default; SET DEBUG_SYNC='now WAIT_FOR change_user'; SET DEBUG_SYNC='thd_cleanup_start SIGNAL continue WAIT_FOR continue_change_user'; --change_user root,,test CONNECTION con1; --REAP SET DEBUG_SYNC='RESET'; CONNECTION default; INSERT INTO t1(name, val) SELECT * FROM INFORMATION_SCHEMA.global_status WHERE variable_name='com_insert'; --echo # With fix, difference of com_insert status should be "0" here. SELECT (SELECT val FROM t1 WHERE id = 2) - (SELECT val FROM t1 WHERE id = 3); --echo # Testing the same scenario with performance_schema. # Make sure we are not running in 5.6 compatiability mode. Else # performance_schema will return empty set. set global SHOW_COMPATIBILITY_56 = 0; truncate t1; --echo # Insert 1 tuple to increment com_insert status. INSERT INTO t1(name, val) VALUES ('dummy', 0); CONNECTION con1; SET DEBUG_SYNC='before_materialize_global_status_array SIGNAL change_user WAIT_FOR continue'; SET DEBUG_SYNC='after_materialize_global_status_array SIGNAL continue_change_user'; --SEND INSERT INTO t1(name, val) SELECT * FROM performance_schema.global_status WHERE variable_name='Handler_commit'; CONNECTION default; SET DEBUG_SYNC='now WAIT_FOR change_user'; SET DEBUG_SYNC='thd_cleanup_start SIGNAL continue WAIT_FOR continue_change_user'; --change_user root,,test CONNECTION con1; --REAP SET DEBUG_SYNC='RESET'; CONNECTION default; INSERT INTO t1(name, val) SELECT * FROM performance_schema.global_status WHERE variable_name='Handler_commit'; --echo # With fix, Handler_commit status should be 1 (select insert during switch user). SELECT (SELECT val FROM t1 WHERE id = 3) - (SELECT val FROM t1 WHERE id = 2); # Cleanup eval set global SHOW_COMPATIBILITY_56=$compatibility_mode; DISCONNECT con1; DROP TABLE t1; --disable_connect_log # Wait till we reached the initial number of concurrent sessions --source include/wait_until_count_sessions.inc