661428 - Sporadic contributor forum posts cause MySQL deadlock

Status: RESOLVED INVALID

(support.mozilla.org :: Forum, task)

Description

[Tanay Gavankar [:tgavankar]]

WebQA Automation found that occasional posts to the contributors forum (both new threads and reply posts) cause an OperationalError, with MySQL deadlocking with the error message, "Deadlock found when trying to get lock; try restarting transaction".

Only applies to allizom, as far as we can tell. 

This has been happening (looking at traceback logs) about once a month since January, all on contributors forum posts (new threads and replies). 

However, in the past 3 days it's spiked and happened ~6 times, but we can't seem to find any rhyme or reason.

Comment 1

[Erik Rose [:erik][:erikrose]]

I took a look at the commits since 5/28 or so, and there's nothing suspicious. Nothing significant even changed in the forums app or in any other relevant DB-hitting code, AFAICT. Innnnteresting.

Comment 2

[James Socol [:jsocol, :james]]

Are there any specific threads or posts that can reliably cause this?

Remember that our databases run on a shared DB environment for both master and slave.

Comment 3

[Liz Henry (:lizzard) (relman/hg->git project)]

Is this still happening? If not, I think we might close this bug since it hasn't been changed in over two years.  Zac, I'm asking you since you look to be the main WebQA automation person at the moment.

Comment 4

[Zac C (:zac)]

Thanks Liz I think that's fine.