There is a high priority approved blueprint for a Neutron PoolMember: https://blueprints.launchpad.net/heat/+spec/loadballancer-pool-members
Thanks, Kevin ________________________________________ From: Christopher Armstrong [[email protected]] Sent: Thursday, November 21, 2013 9:44 AM To: OpenStack Development Mailing List (not for usage questions) Subject: Re: [openstack-dev] [Heat] rough draft of Heat autoscaling API On Thu, Nov 21, 2013 at 5:18 AM, Zane Bitter <[email protected]<mailto:[email protected]>> wrote: On 20/11/13 23:49, Christopher Armstrong wrote: On Wed, Nov 20, 2013 at 2:07 PM, Zane Bitter <[email protected]<mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]>>> wrote: On 20/11/13 16:07, Christopher Armstrong wrote: On Tue, Nov 19, 2013 at 4:27 PM, Zane Bitter <[email protected]<mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]>> <mailto:[email protected]<mailto:[email protected]> <mailto:[email protected]<mailto:[email protected]>>>> wrote: On 19/11/13 19:14, Christopher Armstrong wrote: thought we had a workable solution with the "LoadBalancerMember" idea, which you would use in a way somewhat similar to CinderVolumeAttachment in the above example, to hook servers up to load balancers. I haven't seen this proposal at all. Do you have a link? How does it handle the problem of wanting to notify an arbitrary service (i.e. not necessarily a load balancer)? It's been described in the autoscaling wiki page for a while, and I thought the LBMember idea was discussed at the summit, but I wasn't there to verify that :) https://wiki.openstack.org/wiki/Heat/AutoScaling#LBMember.3F Basically, the LoadBalancerMember resource (which is very similar to the CinderVolumeAttachment) would be responsible for removing and adding IPs from/to the load balancer (which is actually a direct mapping to the way the various LB APIs work). Since this resource lives with the server resource inside the scaling unit, we don't really need to get anything _out_ of that stack, only pass _in_ the load balancer ID. I see a couple of problems with this approach: 1) It makes the default case hard. There's no way to just specify a server and hook it up to a load balancer like you can at the moment. Instead, you _have_ to create a template (or template snippet - not really any better) to add this extra resource in, even for what should be the most basic, default case (scale servers behind a load balancer). We can provide a standard resource/template for this, LoadBalancedServer, to make the common case trivial and only require the user to pass parameters, not a whole template. 2) It relies on a plugin being present for any type of thing you might want to notify. I don't understand this point. What do you mean by a plugin? I was assuming OS::Neutron::PoolMember (not LoadBalancerMember -- I went and looked up the actual name) would become a standard Heat resource, not a third-party thing (though third parties could provide their own through the usual heat extension mechanisms). (fwiw the rackspace load balancer API works identically, so it seems a pretty standard design). At summit and - to the best of my recollection - before, we talked about scaling a generic group of resources and passing notifications to a generic controller, with the types of both defined by the user. I was expecting you to propose something based on webhooks, which is why I was surprised not to see anything about it in the API. (I'm not prejudging that that is the way to go... I'm actually wondering if Marconi has a role to play here.) I think the main benefit of PoolMember is: 1) it matches with the Neutron LBaaS API perfectly, just like all the rest of our resources, which represent individual REST objects. 2) it's already understandable. I don't understand the idea behind notifications or how they would work to solve our problems. You can keep saying that the notifications idea will solve our problems, but I can't figure out how it would solve our problem unless someone actually explains it :) -- IRC: radix Christopher Armstrong Rackspace _______________________________________________ OpenStack-dev mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
