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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
88 lines
1.9 KiB
Text
88 lines
1.9 KiB
Text
# Let's see if FLUSH TABLES WITH READ LOCK blocks COMMIT of existing
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# transactions.
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# We verify that we did not introduce a deadlock.
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# This is intended to mimick how mysqldump and innobackup work.
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# And it requires InnoDB
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--source include/have_innodb.inc
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connect (con1,localhost,root,,);
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connect (con2,localhost,root,,);
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connect (con3,localhost,root,,);
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connection con1;
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CREATE TABLE t1 (a INT) ENGINE=innodb;
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# blocks COMMIT ?
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BEGIN;
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INSERT INTO t1 VALUES(1);
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connection con2;
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FLUSH TABLES WITH READ LOCK;
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connection con1;
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--echo # Sending:
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--send COMMIT
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connection con2;
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--echo # Wait until COMMIT gets blocked.
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let $wait_condition=
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select count(*) = 1 from information_schema.processlist
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where state = "Waiting for backup lock" and info = "COMMIT";
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--source include/wait_condition.inc
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--echo # Verify that 'con1' was blocked and data did not move.
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SELECT * FROM t1;
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UNLOCK TABLES;
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connection con1;
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--echo # Reaping COMMIT
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--reap
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# No deadlock ?
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connection con1;
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BEGIN;
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SELECT * FROM t1 FOR UPDATE;
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connection con2;
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BEGIN;
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send SELECT * FROM t1 FOR UPDATE; # blocked by con1
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sleep 1;
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connection con3;
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send FLUSH TABLES WITH READ LOCK; # blocked by con2
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connection con1;
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COMMIT; # should not be blocked by con3
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connection con2;
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reap;
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COMMIT;
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connection con3;
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reap;
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UNLOCK TABLES;
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# Bug#6732 FLUSH TABLES WITH READ LOCK + COMMIT hangs later FLUSH TABLES
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# WITH READ LOCK
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connection con2;
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COMMIT; # unlock InnoDB row locks to allow insertions
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connection con1;
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BEGIN;
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INSERT INTO t1 VALUES(10);
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FLUSH TABLES WITH READ LOCK;
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connection con2;
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FLUSH TABLES WITH READ LOCK; # bug caused hang here
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UNLOCK TABLES;
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# Bug#7358 SHOW CREATE DATABASE fails if open transaction
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BEGIN;
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SELECT * FROM t1;
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SHOW CREATE DATABASE test;
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COMMIT;
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--echo # Cleanup
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connection default;
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disconnect con1;
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disconnect con2;
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disconnect con3;
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--echo # We commit open transactions when we disconnect: only then we can
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--echo # drop the table.
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DROP TABLE t1;
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--echo # End of 4.1 tests
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