Open Stack

Dolph,

Excuse the delayed reply, was waiting for a brilliant solution from
someone. Without one, personally I'd prefer the cronjob as it seems to be
the type of thing cron was designed for. That will be a painful change as
people now rely on this behavior so I don't know if its feasible. I will be
setting up monitoring for the revocation count and alerting me if it
crosses probably 500 or so. If the problem gets worse then I think a custom
no-op or sql driver is the next step.

Thanks.


On Wed, Jul 15, 2015 at 4:00 PM, Dolph Mathews <dolph.mathews at gmail.com>
wrote:

>
>
> On Wed, Jul 15, 2015 at 4:51 PM, Matt Fischer <matt at mattfischer.com>
> wrote:
>
>> I'm having some issues with keystone revocation events. The bottom line
>> is that due to the way keystone handles the clean-up of these events[1],
>> having more than a few leads to:
>>
>>  - bad performance, up to 2x slower token validation with about 600
>> events based on my perf measurements.
>>  - database deadlocks, which cause API calls to fail, more likely with
>> more events it seems
>>
>> I am seeing this behavior in code from trunk on June 11 using Fernet
>> tokens, but the token backend does not seem to make a difference.
>>
>> Here's what happens to the db in terms of deadlock:
>> 2015-07-15 21:25:41.082 31800 TRACE keystone.common.wsgi DBDeadlock:
>> (OperationalError) (1213, 'Deadlock found when trying to get lock; try
>> restarting transaction') 'DELETE FROM revocation_event WHERE
>> revocation_event.revoked_at < %s' (datetime.datetime(2015, 7, 15, 18, 55,
>> 41, 55186),)
>>
>> When this starts happening, I just go truncate the table, but this is not
>> ideal. If [1] is really true then the design is not great, it sounds like
>> keystone is doing a revocation event clean-up on every token validation
>> call. Reading and deleting/locking from my db cluster is not something I
>> want to do on every validate call.
>>
>
> Unfortunately, that's *exactly* what keystone is doing. Adam and I had a
> conversation about this problem in Vancouver which directly resulted in
> opening the bug referenced on the operator list:
>
>   https://bugs.launchpad.net/keystone/+bug/1456797
>
> Neither of us remembered the actual implemented behavior, which is what
> you've run into and Deepti verified in the bug's comments.
>
>
>>
>> So, can I turn of token revocation for now? I didn't see an obvious no-op
>> driver.
>>
>
> Not sure how, other than writing your own no-op driver, or perhaps an
> extended driver that doesn't try to clean the table on every read?
>
>
>> And in the long-run can this be fixed? I'd rather do almost anything
>> else, including writing a cronjob than what happens now.
>>
>
> If anyone has a better solution than the current one, that's also better
> than requiring a cron job on something like keystone-manage
> revocation_flush I'd love to hear it.
>
>
>> [1] -
>> http://lists.openstack.org/pipermail/openstack-operators/2015-June/007210.html
>>
>> __________________________________________________________________________
>> OpenStack Development Mailing List (not for usage questions)
>> Unsubscribe:
>> OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>
>>
>
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20150721/8d8c28be/attachment.html>