launchpad-dev team mailing list archive

[Stuart Bishop <stuart.bishop@xxxxxxxxxxxxx>]

On Wed, Jul 14, 2010 at 12:19 PM, Michael Hudson
<michael.hudson@xxxxxxxxxxxxx> 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?

-- 
Stuart Bishop <stuart@xxxxxxxxxxxxxxxx>
http://www.stuartbishop.net/