Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Fixed
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10.5.17, 10.6.17, 10.11.7, 11.5.1
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Ubuntu Linux 22.04, n.a.
Description
When I provoke ONE deadlock the Innodb_deadlocks status counter is increase by TWO. This oversubscribes the number of deadlocks happening in a mariadb database.
Documentation states: Total number of InnoDB deadlocks.
https://mariadb.com/kb/en/innodb-status-variables/#innodb_deadlocks
So IMHO it should be 1 and not 2.
Reproducible:
SQL> SHOW GLOBAL STATUS LIKE '%dead%';
|
+------------------+-------+
|
| Variable_name | Value |
|
+------------------+-------+
|
| Innodb_deadlocks | 0 |
|
+------------------+-------+
|
|
|
Session 1> START TRANSACTION;
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Session 2> START TRANSACTION;
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Session 1> UPDATE test SET data = 'bla' WHERE id = 2;
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Session 2> UPDATE test SET data = 'bla' WHERE id = 1524;
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Session 1> UPDATE test SET data = 'bla' WHERE id = 1524;
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Session 2> UPDATE test SET data = 'bla' WHERE id = 2;
|
|
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SQL> SHOW GLOBAL STATUS LIKE '%dead%';
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+------------------+-------+
|
| Variable_name | Value |
|
+------------------+-------+
|
| Innodb_deadlocks | 2 |
|
+------------------+-------+
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Table:
CREATE TABLE `test` ( |
`id` int(10) unsigned NOT NULL AUTO_INCREMENT, |
`data` varchar(128) DEFAULT NULL, |
`ts` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(), |
PRIMARY KEY (`id`) |
);
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Data:
INSERT INTO test SELECT NULL, 'Some data', NOW(); |
INSERT INTO test SELECT NULL, 'Some data', NOW() FROM test; |
...
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Attachments
Issue Links
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MDEV-20043 Innodb_deadlocks status counter
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- Closed
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- relates to
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- Open
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