Open Stack

On Oct 22, 2014, at 12:53 AM, Jakub Libosvar <libosvar at redhat.com> wrote:

> On 10/22/2014 02:26 AM, Maru Newby wrote:
>> We merged caching support for the metadata agent in juno, and backported to icehouse.  It was enabled by default in juno, but disabled by default in icehouse to satisfy the stable maint requirement of not changing functional behavior.
>> 
>> While performance of the agent was improved with caching enabled, it regressed a reported 8x when caching was disabled [1].  This means that by default, the caching backport severely impacts icehouse Neutron's performance.
>> 
>> So, what is the way forward?  We definitely need to document the problem for both icehouse and juno.  Is documentation enough?  Or can we enable caching by default in icehouse?  Or remove the backport entirely.
>> 
>> There is also a proposal to replace the metadata agent’s use of the neutron client in favor of rpc [2].  There were comments on an old bug suggesting we didn’t want to do this [3], but assuming that we want this change in Kilo, is backporting even a possibility given that it implies a behavioral change to be useful?
>> 
>> Thanks,
>> 
>> 
>> Maru
>> 
>> 
>> 
>> 1: https://bugs.launchpad.net/cloud-archive/+bug/1361357
>> 2: https://review.openstack.org/#/c/121782
>> 3: https://bugs.launchpad.net/neutron/+bug/1092043
>> _______________________________________________
>> OpenStack-dev mailing list
>> OpenStack-dev at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>> 
> I thought the performance regression was caused by wrong keystone token
> caching leading to authentication per neutron client instance. Fix was
> backported to Icehouse [1].
> 
> Does it mean this patch hasn't solved the problem and regression is
> somewhere else?

As you say (and as per Ihar and Akihiro’s responses), the problem was fixed.  I was confused by the bug that Oleg’s RPC proposal hard targeted as a related bug and thought the problem wasn’t yet resolved, but looking at it again it appears the bug is a Ubuntu distro issue.  Accordingly, I’ve removed Neutron as a target for that bug.  Apologies for the confusion.


Maru 

> Kuba
> 
> [1] https://review.openstack.org/#/c/120418/
> 
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev