| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2017-09-05 | |||
| 21:01:37 | jaypipes | efried: it's the "how do I request all these related things from the placement REST API" part that has me stumped, not the "please store this structured data in the placement DB" part. | |
| 21:02:31 | efried | jaypipes Right, I can see how to get the structure/inventory data into placement. | |
| 21:02:46 | jaypipes | efried: yes. we're both A-OK on that front. | |
| 21:03:02 | efried | dansmith Sorry it came across that way; I misunderstood some stuff. | |
| 21:03:21 | jaypipes | efried: however, I still don't know a way to make a request of the placement API without essentially reproducing a domain-specific YAML/JSON language to deal with these complex topology requests. | |
| 21:04:55 | efried | dansmith When jaypipes was venting about nova not being a cloud orchestration thingy, I thought he was saying being able to request multiple networks was a cloud orchestration thingy behavior, and that nova shouldn't be in that business. | |
| 21:05:26 | efried | ...Which may indeed be what he was saying - just not suggesting that that actually *happen* :) | |
| 21:05:48 | efried | jaypipes Right, so go with me on this "multiple instances of the `resources=` key" thing for a sec. | |
| 21:06:25 | dansmith | efried: I think what he was saying was that expecting nova to do lots of steps for you (i.e. determine and reserve multiple resources) as part of a single boot request is really getting into orchestration | |
| 21:07:11 | openstackgerrit | Brianna Poulos proposed openstack/nova master: Add trusted_certificates to REST API https://review.openstack.org/486204 | |
| 21:07:25 | efried | So I'm confused as to how VCPU+MEM_MB+DISK_GB isn't determining and reserving multiple resources. | |
| 21:07:40 | dansmith | efried: are you just being sarcastic and difficult now? | |
| 21:07:43 | dansmith | obviously that's not | |
| 21:08:33 | efried | No, dansmith, I'm actually this obtuse I'm afraid. Mostly from lack of experience (and a disproportionate lack of inhibition to speak up and ask questions). | |
| 21:08:48 | efried | But again, apologies, I think I understand what you mean now. | |
| 21:08:56 | efried | when you said "multiple resources" | |
| 21:09:13 | efried | you meant "multiple disparate resources of the same class". | |
| 21:09:17 | efried | mahbad. | |
| 21:09:22 | jaypipes | efried: hold up... I just thought of something... gimme a minute to flesh it out in my brain. | |
| 21:09:58 | efried | btw jaypipes I realized as I started typing it why the 'multiple querystring keys' thing is a nonstarter if traits is its own qs key... | |
| 21:10:17 | dansmith | efried: I mean things like nova going to cinder to create, image, and attach a volume, and to neutron to create multiple ports for a complex network layout, and then to some other service to arrange for party balloons to be sent in ten minutes, and then, finally, to boot the instance | |
| 21:11:44 | efried | dansmith Rightright. And I think again the reason I'm confused as to why we wouldn't want that is because that (at least the neutron & cinder stuff) is part and parcel of what nova does today, and therefore what I think of as being in nova's purview. | |
| 21:12:32 | efried | and if we're not taking away at least the neutron &/| cinder stuff, then presumably there's going to have to be an answer for it in the placement world. | |
| 21:12:51 | efried | which solution, if we're gonna solve it for neutron & cinder, would seem like it oughtta work for whatever. | |
| 21:13:03 | efried | although I'm *not* suggesting it should go talk to just any external service. | |
| 21:14:09 | efried | In the case of neutron, the model we have today for VFs is that you create your ports in neutron and then some gizmo in nova knows to associate that with the physnet tags from the [pci]passthrough_whitelist (which is one of jaypipes's bugbears) | |
| 21:14:09 | dansmith | I don't follow | |
| 21:15:06 | dansmith | we're not talking about getting rid of neutron or our talking to it, but just not trying to build requests for complex things into nova's API, IMHO | |
| 21:15:26 | dansmith | I think I've lost track of why this is coming up in the context of placement | |
| 21:17:00 | jaypipes | I'm still pastebinning. :) | |
| 21:17:05 | efried | dansmith Well, the premise - which I *think* started with jaypipes (see comments here https://review.openstack.org/#/c/497965/) - is that we want to phase out the PCI device management gorp that's been frankensteined over the years. | |
| 21:17:41 | jaypipes | guys, can I hit pause on this conversation for 5 minutes so I can finish my braindump? | |
| 21:17:48 | efried | ...with some kind of "generic device manager" which talks to Placement | |
| 21:17:50 | efried | sure. | |
| 21:19:26 | dansmith | efried: definitely, to the extent we can | |
| 21:20:22 | openstackgerrit | Dan Smith proposed openstack/nova-specs master: Add migration-allocations spec https://review.openstack.org/498510 | |
| 21:59:53 | cfriesen__ | when calling a remotable object function, does nova-conductor do a keystone token validation? | |
| 22:01:40 | dansmith | no | |
| 22:21:40 | openstackgerrit | Matt Riedemann proposed openstack/nova-specs master: Spec for flavor description https://review.openstack.org/501017 | |
| 22:21:42 | mriedem | Kevin_Zheng: ^ | |
| 22:23:43 | jaypipes | efried, dansmith: sorry, dinner got in the way.. | |
| 22:23:55 | jaypipes | efried, dansmith: dumped some thoughts here: http://paste.openstack.org/show/620456/ | |
| 22:24:46 | efried | jaypipes ... | |
| 22:25:54 | jaypipes | efried: yes? | |
| 22:26:18 | efried | jaypipes Sorry, that's "Message received, processing..." | |
| 22:26:30 | jaypipes | efried: ack | |
| 22:29:19 | efried | jaypipes Yes, just so. But I thought this was the part we were all in sync with. The part we hadn't yet come to grips with was the hand-waving on L35-6. | |
| 22:30:14 | jaypipes | efried: no, I can come up with an *internal* representation for the request. what I can't figure out is how to map that to a *single* REST API call. | |
| 22:30:24 | efried | Right. | |
| 22:31:48 | efried | jaypipes Don't kill me don't kill me but... what if I numbered the query param keys? | |
| 22:32:10 | efried | resources1=...&traits1=...&resources2=...&traits2=... | |
| 22:32:34 | jaypipes | efried: uhm, eww? :) | |
| 22:32:56 | efried | Well, yeah it's eww, that's a given. But it's clear that it could work. | |
| 22:33:07 | efried | It could also conceivably answer the thing where it matters what order we attach devices in... | |
| 22:33:18 | efried | ...which some people care about. | |
| 22:33:34 | jaypipes | efried: not sure I follow why the attachment order matters to the placement API. | |
| 22:33:55 | efried | It doesn't, but when the request comes in, don't those keys come through? Mebbe not, sorry. | |
| 22:35:21 | efried | Anyway, for the general case, non-numbered querystring keys work just fine; in fact they don't even have to be numbers - we just parse the prefix and group by the suffix, whatever it is. | |
| 22:36:14 | jaypipes | efried: the problem with adding this to the placement REST API is that then we're adding a bunch of orchestration-like logic into the placement service. | |
| 22:36:48 | jaypipes | efried: instead of keeping that out of placement and relying on the caller to placement understanding that the request contains a number of "subrequests" that are for specific complex types. | |
| 22:37:07 | efried | jaypipes Yeah, I admit I don't understand what is meant by "orchestration" and where that line is drawn. | |
| 22:37:36 | jaypipes | efried: dealing with lots of resources as a group is orchestration. | |
| 22:38:08 | jaypipes | efried: where the relationship between the resources, the dependencies between them, the constraints that each imposes on each other, etc. that's orchestration. | |
| 22:38:39 | jaypipes | efried: whereas placement is designed to be a fast, efficient method of determining providers of resources for a given simple request for capacity. | |
| 22:41:21 | cdent | jaypipes: can you clarify something for me: I’m not fully grokking why, in your paste, we need to make multiple requests to /a_c ? Is it is because at the point we don’t have a good way to express (in one request) what we want or is there more than that? | |
| 22:42:23 | efried | 're having trouble expressing it under the current design, not because it inherently crosses the line to "orchestration". | |
| 22:42:23 | efried | jaypipes I'm probably being obtuse again, but I still don't really see how what we're talking about here doesn't still fall into that description. Placement is designed to grab resources from multiple resource providers. From a way-zoomed-out view, saying "you can only get stuff from a given resource class from a single provider" seems like an arbitrary limitation. Zoom back in, and it's one that seems imposed because we | |
| 22:42:47 | cdent | jaypipes: on line 50 it is GROUP_A on the first go round and GROUP_B on the second? | |
| 22:43:37 | efried | cdent Yeah; and/or L49 could be different egress bandwidth numbers | |
| 22:43:44 | cdent | thanks | |
| 22:44:01 | jaypipes | query parameters. | |
| 22:44:01 | jaypipes | cdent: a couple reasons for that. the first is that it's difficult for me to map the concept of related sub-requests in a single REST API call (again, without resorting to some DSL-ish request payload) and b) because I suspect these types of use cases are just the tip of the iceberg and that the logic that relates various things with each other (GPUs, FPGAs, NIC HA groups, etc) will be different and not possible to cleanly express with simple | |
| 22:44:51 | jaypipes | cdent: and yes, it would be GROUP_A on the first go around and GROUP_B on the second. | |
| 22:45:08 | cdent | jaypipes: next question: step 4 sounds like a pretty big step backwards for the goals we originally expressed for allocation_candidates | |
| 22:45:21 | jaypipes | cdent: could also have different amounts of egress bandwidth, different affinity policies, different all sorts of things, frnakly | |
| 22:45:32 | jaypipes | cdent: Yupppp! | |
| 22:45:37 | cdent | why can’t we have a complete allocation_requests (just to be explicit) | |
| 22:45:48 | jaypipes | cdent: it removes the whole opaqueness aspect of the allocation request :() | |
| 22:45:57 | cdent | yes much :( | |
| 22:46:07 | efried | Is it because the allocation request is keyed by resource class? | |
| 22:46:15 | efried | (haven't looked at that guy yet) | |
| 22:46:41 | jaypipes | cdent: we can't have a complete allocation_requests unless placement is passed all of the logic about relationship between sub-resources | |
| 22:47:03 | cdent | I thought that’s what nested was providing us? | |
| 22:47:04 | jaypipes | efried: the allocation request is not keyed by resource class, no. | |
| 22:47:23 | jaypipes | efried: the allocation request is essentially the request payload to PUT /allocations/{consumer_uuid} | |
| 22:47:29 | openstackgerrit | Michael Still proposed openstack/nova master: Add release note for requiring shred 8.22 or above. https://review.openstack.org/501022 | |
| 22:48:19 | cdent | jaypipes: related, have you yet seen: http://lists.openstack.org/pipermail/openstack-dev/2017-September/121824.html from avolkov ? | |
| 22:48:21 | efried | jaypipes And it must be able to contain resources from different RPs. So why would there be a limitation that RCs therein be unique? | |
| 22:48:32 | efried | cdent That's what started this whole thing :) | |
| 22:48:38 | cdent | ah, good | |
| 22:48:50 | efried | cdent Back around http://eavesdrop.openstack.org/irclogs/%23openstack-nova/%23openstack-nova.2017-09-05.log.html#t2017-09-05T15:37:39 | |
| 22:49:01 | cdent | presumably the response to option 2 is “no” | |
| 22:49:04 | cdent | as that’s not "real" | |
| 22:49:12 | jaypipes | cdent: nested resource providers allows the placement API to understand whether, say, a PF that provides some VFs is on a particular compute node. Nested providers doesn't, however, solve the problem of how do we model the *request* for resources when the user doesn't know that there is a nested relationship between things. | |
| 22:49:40 | jaypipes | efried: there is no such limitation. I'm not sure what you're getting at. | |
| 22:50:19 | mikal | mriedem: I am a bad man and realized once that shred patch had merged that it probably should have had a reno, so I've added one in https://review.openstack.org/#/c/501022/ | |
| 22:51:14 | efried | jaypipes What you and cdent were saying about breaking opaqueness? And a step backwards for original goals of allocation_candidates. I didn't catch where that came from. | |
| 22:51:15 | cdent | jaypipes: I get that the request modeling is a limitation, but if were to set that aside for a moment and we could express the request well then the we could present a complete set of allocations in response, right? The limitation as described in your paste is because the current request doesn’t have all the state. | |
| 22:52:03 | cdent | efried: ideally it would be possible to take the first item in the allocation_request list and send that to /allocations/{consumer_uuid} without modifications to make a “claim” | |
| 22:52:23 | efried | cdent Why doesn't that still work in this scenario? | |