mirror of
https://github.com/MariaDB/server.git
synced 2025-08-24 03:12:20 +02:00
bead24b7f3
Remove one of the major sources of race condiitons in mariadb-test. Normally, mariadb_close() sends COM_QUIT to the server and immediately disconnects. In mariadb-test it means the test can switch to another connection and sends queries to the server before the server even started parsing the COM_QUIT packet and these queries can see the connection as fully active, as it didn't reach dispatch_command yet. This is a major source of instability in tests and many - but not all, still less than a half - tests employ workarounds. The correct one is a pair count_sessions.inc/wait_until_count_sessions.inc. Also very popular was wait_until_disconnected.inc, which was completely useless, because it verifies that the connection is closed, and after disconnect it always is, it didn't verify whether the server processed COM_QUIT. Sadly the placebo was as widely used as the real thing. Let's fix this by making mariadb-test `disconnect` command _to wait_ for the server to confirm. This makes almost all workarounds redundant. In some cases count_sessions.inc/wait_until_count_sessions.inc is still needed, though, as only `disconnect` command is changed: * after external tools, like `exec $MYSQL` * after failed `connect` command * replication, after `STOP SLAVE` * Federated/CONNECT/SPIDER/etc after `DROP TABLE` and also in some XA tests, because an XA transaction is dissociated from the THD very late, after the server has closed the client connection. Collateral cleanups: fix comments, remove some redundant statements: * DROP IF EXISTS if nothing is known to exist * DROP table/view before DROP DATABASE * REVOKE privileges before DROP USER etc
74 lines
2 KiB
Text
74 lines
2 KiB
Text
# Let's see if FLUSH TABLES WITH READ LOCK can be killed when waiting
|
|
# for running commits to finish (in the past it could not)
|
|
# This will not be a meaningful test on non-debug servers so will be
|
|
# skipped.
|
|
|
|
# This also won't work with the embedded server test
|
|
--source include/not_embedded.inc
|
|
|
|
--source include/have_debug.inc
|
|
--source include/have_debug_sync.inc
|
|
|
|
# This test needs transactional engine as otherwise COMMIT
|
|
# won't block FLUSH TABLES WITH GLOBAL READ LOCK.
|
|
--source include/have_innodb.inc
|
|
|
|
connect (con1,localhost,root,,);
|
|
connect (con2,localhost,root,,);
|
|
connection con1;
|
|
|
|
--disable_warnings
|
|
DROP TABLE IF EXISTS t1;
|
|
--enable_warnings
|
|
SET DEBUG_SYNC= 'RESET';
|
|
CREATE TABLE t1 (kill_id INT) engine = InnoDB;
|
|
INSERT INTO t1 VALUES(connection_id());
|
|
|
|
connection default;
|
|
--echo # Start transaction.
|
|
BEGIN;
|
|
INSERT INTO t1 VALUES(connection_id());
|
|
--echo # Ensure that COMMIT will pause once it acquires protection
|
|
--echo # against its global read lock.
|
|
SET DEBUG_SYNC='ha_commit_trans_after_acquire_commit_lock SIGNAL acquired WAIT_FOR go';
|
|
|
|
--echo # Sending:
|
|
--send COMMIT
|
|
|
|
connection con1;
|
|
--echo # Wait till COMMIT acquires protection against global read
|
|
--echo # lock and pauses.
|
|
SET DEBUG_SYNC='now WAIT_FOR acquired';
|
|
--echo # Sending:
|
|
send FLUSH TABLES WITH READ LOCK;
|
|
|
|
connection con2;
|
|
SELECT ((@id := kill_id) - kill_id) FROM t1 LIMIT 1;
|
|
|
|
--echo # Wait till FLUSH TABLES WITH READ LOCK blocks due
|
|
--echo # to active COMMIT
|
|
let $wait_condition=
|
|
select count(*) = 1 from information_schema.processlist
|
|
where state = "Waiting for backup lock"
|
|
and info = "flush tables with read lock";
|
|
--source include/wait_condition.inc
|
|
|
|
--echo # Kill connection 'con1'.
|
|
KILL CONNECTION @id;
|
|
|
|
connection con1;
|
|
--echo # Try to reap FLUSH TABLES WITH READ LOCK,
|
|
--echo # it fail due to killed statement and connection.
|
|
--error 1317,2013
|
|
reap;
|
|
|
|
connection con2;
|
|
--echo # Resume COMMIT.
|
|
SET DEBUG_SYNC='now SIGNAL go';
|
|
|
|
connection default;
|
|
--echo # Reaping COMMIT.
|
|
--reap
|
|
disconnect con2;
|
|
DROP TABLE t1;
|
|
SET DEBUG_SYNC= 'RESET';
|