On Wed, 14 Jul 2010 14:08:28 Stuart Bishop wrote: > On Wed, Jul 14, 2010 at 12:19 PM, Michael Hudson > > <[email protected]> wrote: > > UPDATE CodeImportMachine SET heartbeat=CURRENT_TIMESTAMP AT TIME ZONE > > 'UTC' WHERE CodeImportMachine.id = %s took 8 seconds in this case. I > > think this must be a result of some kind of locking, but I can't really > > imagine what as this is the only method I can think of that writes to > > this table routine. Maybe many concurrent calls to the same method are > > contending with each other? Seems a tad unlikely though. > > If job A on machine M does that update, other jobs on that machine > cannot make the same update until job A commits or a aborts the > transaction. Are there multiple processes on a machine trying to > update the heart, and if so, are they running in autocommit mode or > committing directly after updating the timestamp?
Yes there are multiple jobs, up to 10 on our fast box. I don't remember enough to know exactly what is causing the slowdown. Nothing changed on the code import worker over the last several months at least. Tim _______________________________________________ Mailing list: https://launchpad.net/~launchpad-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~launchpad-dev More help : https://help.launchpad.net/ListHelp
