openstack team mailing list archive

[John Griffith <john.griffith@xxxxxxxxxxxxx>]

On Sun, Jul 7, 2013 at 5:43 PM, Sam Morrison <sorrison@xxxxxxxxx> wrote:

> Hi,
>
> I'm wondering if anyone is using cinder and is having issue with the list
> volumes API call.
>
> We have a grizzly install and we're at about 160 active volumes in cinder
> at the moment.
>
> To do "cinder list" with a tenant that has about 140 volumes it takes
> about 6 seconds.
> API calls on a specific volume are done in about 0.1 seconds so I'm happy
> with the API servers, it's the code I'm worried about.
>
> Doing a "cinder list --all-tenants" as an admin it takes about 20 seconds.
>
> Looking at the code it seems as an admin it will iterate over every volume
> 3 times and do a db requests on each volume.
> As a normal user it iterates over every volume once.
>
> The for loops are for adding glance image information and as an admin it
> also adds host and tenant information which is in the same table so it's a
> bit strange that it's doing more DB calls.
>
> Does anyone use cinder with more that just a couple of active volumes and
> if so how do they when requests are so slow?
> We have 36 cinder-api servers handling requests and they aren't under
> significant load. Also our DB cluster is handling things fine.
>
> Cheers,
> Sam
>
>
>
>
>
> _______________________________________________
> Mailing list: https://launchpad.net/~openstack
> Post to     : openstack@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~openstack
> More help   : https://help.launchpad.net/ListHelp
>

Hi Sam,
Definitely some things in this area that cause problems at scale, I'm not
sure exactly where you're looking at in terms of the loops?

We did recently submit a bug fix [1] related to some of this, but I don't
think it covers the case you're describing and it has NOT been backported
to Grizzly.

If you'd like to point me specifically to the loops your describing I'm
happy to take a look and see if we can fix this up.

Thanks,
John

[1] http://tinyurl.com/jwgpxpr