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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
83 lines
2.5 KiB
Text
83 lines
2.5 KiB
Text
--source include/have_innodb.inc
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--disable_query_log
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call mtr.add_suppression("InnoDB: Transaction was aborted due to ");
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--enable_query_log
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CREATE TABLE t1 (
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pkey int NOT NULL PRIMARY KEY,
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c int
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) ENGINE=InnoDB;
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INSERT INTO t1 VALUES(1,1);
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CREATE TABLE t2 (
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pkey int NOT NULL PRIMARY KEY,
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c int
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) ENGINE=InnoDB DEFAULT CHARSET=latin1;
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INSERT INTO t2 VALUES (2, NULL);
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# The following table is to increase transaction weight on deadlock resolution
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CREATE TABLE t3 (c int) engine = InnoDB;
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INSERT INTO t3 VALUES (10), (20), (30), (40), (50);
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--let $i= 2
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--let $delete= 2
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--let $update= 1
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--connect(con1, localhost,root,,)
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while($i) {
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--connection default
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START TRANSACTION; # trx 1
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# The following update is necessary to increase the transaction weight, which is
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# calculated as the number of locks + the number of undo records during deadlock
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# report. Victim's transaction should have minimum weight. We need trx 2 to be
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# choosen as victim, that's why we need to increase the current transaction
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# weight.
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UPDATE t3 SET c=c+1000;
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SELECT * FROM t1 FOR UPDATE;
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--connection con1
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START TRANSACTION; # trx 2
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# 1) read record from t2, lock it
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# 2) check if the read record should be deleted, i.e. read record from t1,
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# as the record from t1 is locked by trx 1, the subselect will be suspended.
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# see 'while' loop in mysql_delete() or mysql_update() and
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# select->skip_record(thd) call for details.
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if ($i == $delete) {
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--send DELETE FROM t2 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey)
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}
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if ($i == $update) {
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--send UPDATE t2 SET pkey=pkey+10 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey)
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}
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--connection default
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let $wait_condition=
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SELECT count(*) = 1 FROM information_schema.processlist
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WHERE (state = 'Sending data' OR state = "Updating")
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AND (info LIKE 'delete from t2 where%' OR
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info LIKE 'UPDATE t2 SET pkey=pkey+10 WHERE%');
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--source include/wait_condition.inc
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# The record from t2 is locked by the previous delete, so trx 2 is waiting for
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# trx 1, and trx 1 will be blocked by trx 2 with the following SELECT. So we
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# have deadlock here. And trx 2 is chosen as deadlock victim as trx 1 has
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# greater weight.
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SELECT * FROM t2 FOR UPDATE;
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COMMIT;
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--connection con1
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# If the bug is not fixed, there will be assertion failure as
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# mysql_delete()/mysql_update() will continue execution despite its subselect
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# got deadlock error
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--error ER_LOCK_DEADLOCK
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--reap
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COMMIT;
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--dec $i
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}
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--disconnect con1
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--connection default
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DROP TABLE t1,t2,t3;
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