Open Stack

TLDR: We have the capacity to do this.  One scale job can be absorbed 
into our existing test infrastructure with minimal impact.

On 04/19/2017 07:50 AM, Flavio Percoco wrote:
> On 18/04/17 14:28 -0400, Emilien Macchi wrote:
>> On Mon, Apr 17, 2017 at 3:52 PM, Justin Kilpatrick
>> <jkilpatr at redhat.com> wrote:
>>> Because CI jobs tend to max out about 5 nodes there's a whole class of
>>> minor bugs that make it into releases.
>>>
>>> What happens is that they never show up in small clouds, then when
>>> they do show up in larger testing clouds the people deploying those
>>> simply work around the issue and get onto what they where supposed to
>>> be testing. These workarounds do get documented/BZ'd but since they
>>> don't block anyone and only show up in large environments they become
>>> hard for developers to fix.
>>>
>>> So the issue gets stuck in limbo, with nowhere to test a patchset and
>>> no one owning the issue.
>>>
>>> These issues pile up and pretty soon there is a significant difference
>>> between the default documented workflow and the 'scale' workflow which
>>> is filled with workarounds which may or may not be documented
>>> upstream.
>>>
>>> I'd like to propose getting these issues more visibility to having a
>>> periodic upstream job that uses 20-30 ovb instances to do a larger
>>> deployment. Maybe at 3am on a Sunday or some other time where there's
>>> idle execution capability to exploit. The goal being to make these
>>> sorts of issues more visible and hopefully get better at fixing them.
>>
>> Wait no, I know some folks at 3am on a Saturday night who use TripleO
>> CI (ok that was a joke).
>
> Jokes apart, it really depends on the TZ and when you schedule it. 3:00
> UTC on a
> Sunday is Monday 13:00 in Sydney :) Saturdays might work better but
> remember
> that some countries work on Sundays.

With the exception of the brief period where the ovb jobs were running 
at full capacity 24 hours a day, there has always been a lull in 
activity during early morning UTC.  Yes, there are people working during 
that time, but generally far fewer and the load on TripleO CI is at its 
lowest point.  Honestly I'd be okay running this scale job every night, 
not just on the weekend.  A week of changes is a lot to sift through if 
a scaling issue creeps into one of the many, many projects that affect 
such things in TripleO.

Also, I should note that we're not currently being constrained by 
absolute hardware limits in rh1.  The reason I haven't scaled our 
concurrent jobs higher is that there is already performance degradation 
when we have a full 70 jobs running at once.  This type of scale job 
would require a lot of theoretical resources, but those 30 compute nodes 
are mostly going to be sitting there idle while the controller(s) get 
deployed, so in reality their impact on the infrastructure is going to 
be less than if we just added more concurrent jobs that used 30 
additional nodes.  And we do have the memory/cpu/disk to spare in rh1 to 
spin up more vms.

We could also take advantage of heterogeneous OVB environments now so 
that the compute nodes are only 3 GB VMs instead of 8 as they are now. 
That would further reduce the impact of this sort of job.  It would 
require some tweaks to how the testenvs are created, but that shouldn't 
be a problem.

>
>>> To be honest I'm not sure this is the best solution, but I'm seeing
>>> this anti pattern across several issues and I think we should try and
>>> come up with a solution.
>>>
>>
>> Yes this proposal is really cool. There is an alternative to run this
>> periodic scenario outside TripleO CI and send results via email maybe.
>> But it is something we need to discuss with RDO Cloud people and see
>> if we would have such resources to make it on a weekly frequency.
>>
>> Thanks for bringing this up, it's crucial for us to have this kind of
>> feedback, now let's take actions.
>
> +1
>
> Flavio
>
>
>
> __________________________________________________________________________
> 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
>