Hmmm...."Error 1213: Deadlock found when trying to get lock" is from MySQL rather than from mysqli. So the error message has come from the db at some point but that seems at odds with the lack of a latest deadlock section in 'show engine innodb status'. I'm not aware of an option that if enabled would not report deadlocks in this way.
In your test cases, if you enable 'innodb_print_all_deadlocks' option do you see a deadlock reported in the mysql error log? (With isolation level at read commited, I'm afraid I can't still trigger a deadlock for copy pages/collections) -- You received this bug notification because you are a member of Mahara Contributors, which is subscribed to Mahara. Matching subscriptions: Subscription for all Mahara Contributors -- please ask on #mahara-dev or mahara.org forum before editing or unsubscribing it! https://bugs.launchpad.net/bugs/1514608 Title: MySQL deadlock issues with simultaneous users Status in Mahara: In Progress Status in Mahara 1.10 series: In Progress Status in Mahara 15.04 series: In Progress Status in Mahara 15.10 series: In Progress Status in Mahara 16.04 series: In Progress Bug description: The patch in Bug 1492919 resolved the deadlock issues for some users, but others are still reporting that they are getting deadlocks. This seems to be an issue unique to MySQL, and it can happen with as few as 2 or 3 concurrent users. It has been reported across all stable versions. Strangely, it seems to be a relatively recent issue (i.e. we never heard this with Mahara 1.8 or 1.7, etc), so this suggests it was triggered by something that changed fairly recently. One possible candidate is our switch to the mysqli driver (before that Mahara wasn't doing transactions at all, in mysql). See also: * https://mahara.org/interaction/forum/topic.php?id=7309 * https://mahara.org/interaction/forum/topic.php?id=7432 To manage notifications about this bug go to: https://bugs.launchpad.net/mahara/+bug/1514608/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~mahara-contributors Post to : mahara-contributors@lists.launchpad.net Unsubscribe : https://launchpad.net/~mahara-contributors More help : https://help.launchpad.net/ListHelp
