[openstack-dev] [Neutron][qa] Parallel testing update

Jay Pipes jaypipes at gmail.com
Mon Jan 6 16:38:11 UTC 2014

On Mon, 2014-01-06 at 17:04 +0100, Salvatore Orlando wrote:
> I have already discussed the matter with Jay on IRC, even if for a
> different issue.
> In this specific case 'batching' will have the benefit of reducing the
> rootwrap overhead.


> However, it seems the benefit from batching is not resolutive. I admit
> I have not run tests in the gate with batching; I've just tested in an
> environment without significant load, obtaining a performance increase
> of less than 10%.

Well, 10% is 10% better than nothing ;) And add in the (significant)
rootwrap costs, and I think it's certainly worth looking into.

> From what I gathered even if commands are 'batched' to ovs-vsctl,
> operations are still individually performed on the kernel module. I
> did not investigate whether the cli commands sends a single or
> multiple commands on the ovsdb interface.
> Nevertheless, another thing to note is that it's not just ovs-vsctl
> that becomes very slow, but also, and more often than that, ovs-ofctl,
> for which there is no batching.

Ah, I did not realize ovs-ofctl had no batch mode. That's a shame...

> Summarising, I'm not opposed to batching for ovs-vsctl, and I would
> definitely welcome it; I just don't think it will be the ultimate
> solution.

Yep, understood.


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