<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Tue, Mar 4, 2014 at 5:46 AM, Sean Dague <span dir="ltr"><<a href="mailto:sean@dague.net" target="_blank">sean@dague.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="">On 03/03/2014 11:32 PM, Dean Troyer wrote:<br>
> On Mon, Mar 3, 2014 at 8:36 PM, Kyle Mestery <<a href="mailto:mestery@noironetworks.com">mestery@noironetworks.com</a><br>
</div><div><div class="h5">> <mailto:<a href="mailto:mestery@noironetworks.com">mestery@noironetworks.com</a>>> wrote:<br>
><br>
> In all cases today with Open Source plugins, Neutron agents have run<br>
> on the hosts. For OpenDaylight, this is not the case. OpenDaylight<br>
> integrates with Neutron as a ML2 MechanismDriver. But it has no<br>
> Neutron code on the compute hosts. OpenDaylight itself communicates<br>
> directly to those compute hosts to program Open vSwitch.<br>
><br>
><br>
><br>
> devstack doesn't provide a way for me to express this today. On the<br>
> compute hosts in the above scenario, there is no "q-*" services<br>
> enabled, so the "is_neutron_enabled" function returns 1, meaning no<br>
> neutron.<br>
><br>
><br>
> True and working as designed.<br>
><br>
><br>
> And then devstack sets Nova up to use nova-networking, which fails.<br>
><br>
><br>
> This only happens if you have enabled nova-network. Since it is on by<br>
> default you must disable it.<br>
><br>
><br>
> The patch I have submitted [1] modifies "is_neutron_enabled" to<br>
> check for the meta neutron service being enabled, which will then<br>
> configure nova to use Neutron instead of nova-networking on the<br>
> hosts. If this sounds wonky and incorrect, I'm open to suggestions<br>
> on how to make this happen.<br>
><br>
><br>
> From the review:<br>
><br>
> is_neutron_enabled() is doing exactly what it is expected to do, return<br>
> success if it finds any "q-*" service listed in ENABLED_SERVICES. If no<br>
> neutron services are configured on a compute host, then this must not<br>
> say they are.<br>
><br>
> Putting 'neutron' in ENABLED_SERVICES does nothing and should do nothing.<br>
><br>
> Since you are not implementing the ODS as a Neutron plugin (as far as<br>
> DevStack is concerned) you should then treat it as a system service and<br>
> configure it that way, adding 'opendaylight' to ENABLED_SERVICES<br>
> whenever you want something to know it is being used.<br>
><br>
><br>
><br>
> Note: I have another patch [2] which enables an OpenDaylight<br>
> service, including configuration of OVS on hosts. But I cannot check<br>
> if the "opendaylight" service is enabled, because this will only run<br>
> on a single node, and again, not on each compute host.<br>
><br>
><br>
> I don't understand this conclusion. in multi-node each node gets its own<br>
> specific ENABLED_SERVICES list, you can check that on each node to<br>
> determine how to configure that node. That is what I'm trying to<br>
> explain in that last paragraph above, maybe not too clearly.<br>
<br>
</div></div>So in an Open Daylight environment... what's running on the compute host<br>
to coordinate host level networking?<br>
<span class="HOEnZb"><font color="#888888"><br></font></span></blockquote><div>Nothing. OpenDaylight communicates to each host using OpenFlow and OVSDB</div><div>to manage networking on the host. In fact, this is one huge advantage for the</div>
<div>ODL MechanismDriver in Neutron, because it's one less agent running on the host.</div><div><br></div><div>Thanks,</div><div>Kyle</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<span class="HOEnZb"><font color="#888888">
-Sean<br>
<br>
--<br>
Sean Dague<br>
Samsung Research America<br>
<a href="mailto:sean@dague.net">sean@dague.net</a> / <a href="mailto:sean.dague@samsung.com">sean.dague@samsung.com</a><br>
<a href="http://dague.net" target="_blank">http://dague.net</a><br>
<br>
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