| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2018-04-12 | |||
| 13:32:56 | stephenfin | What I'm saying is there's not reason we shouldn't fit N guest NUMA nodes on the same host NUMA node | |
| 13:32:57 | efried | but the other way around is okay | |
| 13:33:09 | stephenfin | efried: Yeah, precisely | |
| 13:33:15 | sahid | stephenfin: it's not what we do | |
| 13:33:29 | bauzas | so the big thing is | |
| 13:33:33 | bauzas | now we know that | |
| 13:33:38 | bauzas | should Placement do that ? | |
| 13:33:41 | bauzas | I don't think so | |
| 13:33:45 | stephenfin | sahid: Indeed, and I think we can change that | |
| 13:33:47 | bauzas | leave that logic to the filter | |
| 13:33:53 | stephenfin | bauzas: No, neither do I | |
| 13:34:01 | bauzas | what Placement would return is just a list of potential targets | |
| 13:34:12 | stephenfin | So long as we can still ensure at least one guest NUMA node is affined with a given host NUMA node | |
| 13:34:17 | bauzas | some can run that workload but on a single node, some can do that better | |
| 13:34:19 | stephenfin | For things like PCI devices and the likes | |
| 13:34:26 | bauzas | so the filter will pick the best one | |
| 13:34:28 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: RP list: member_of and resources parameters (v1.3, v1.4) https://review.openstack.org/511183 | |
| 13:34:29 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: RP delete inventories (v1.5) https://review.openstack.org/514642 | |
| 13:34:30 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: CLI for traits (v1.6) https://review.openstack.org/514643 | |
| 13:34:31 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Resource class set (v1.7) https://review.openstack.org/514644 | |
| 13:34:32 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Usages per project and user (v1.8, v1.9) https://review.openstack.org/514646 | |
| 13:34:33 | stephenfin | And vSwitches :) | |
| 13:34:33 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: CLI allocation candidates (v1.10) https://review.openstack.org/514647 | |
| 13:34:34 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: New dict format of allocations (v1.11, v1.12) https://review.openstack.org/542819 | |
| 13:34:34 | Shilpa | stephenfin: Hi, noVNC 1.0.0, i have checked logs http://logs.openstack.org/72/550172/2/check/tempest-full/f6945b6/job-output.txt.gz, and observed that 1 test case is failed, and that is tempest.api.compute.servers.test_novnc.NoVNCConsoleTestJSON.test_novnc[id-c640fdff-8ab4-45a4-a5d8-7e6146cbd0dc] | |
| 13:34:35 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Transactionally update allocations (v1.13) https://review.openstack.org/546674 | |
| 13:34:36 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Add nested resource providers (v1.14) https://review.openstack.org/546675 | |
| 13:34:37 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Limit allocation candidates (v1.15, v1.16) https://review.openstack.org/548043 | |
| 13:34:38 | openstackgerrit | Andrey Volkov proposed openstack/osc-placement master: Allocation candidates parameter: required (v1.17) https://review.openstack.org/548326 | |
| 13:34:44 | bauzas | oh shit, gerrit dropbomb | |
| 13:34:47 | efried | Placement will give you candidates telling you exactly which NUMA nodes the *actual* resources come from. The virt driver must adhere to that. What it turns around and tells the guest is entirely up to your conscience :) | |
| 13:34:56 | sahid | stephenfin: what do you want to change? | |
| 13:35:17 | Shilpa | stephengin: checked there, URL is correct though 'http://217.182.140.77:6080/vnc.html?path=websockify?token=30848df8-99b2-4a0c-a615-51a5a444660d' | |
| 13:35:21 | bauzas | efried: Placement will give hosts that match the possibility to support a guest having a specific topology | |
| 13:35:30 | stephenfin | Shilpa: Indeed. I thought that was because of the change in the path but your change apparently works with both 1.0 and pre-1.0 | |
| 13:35:36 | stephenfin | Shilpa: So I don't know what's going on | |
| 13:35:45 | efried | bauzas: Maybe. | |
| 13:35:46 | bauzas | efried: but the filter could restrict that list | |
| 13:35:50 | efried | bauzas: Exactly. | |
| 13:36:05 | efried | The filter is allowed to be stricter than placement. That's... kind of its job. | |
| 13:36:06 | bauzas | efried: okay, so I feel numbered request groups can still work | |
| 13:36:10 | stephenfin | sahid: If a user requests N nodes, then nova should place those on host NUMA nodes as necessary | |
| 13:36:12 | efried | yes, agree completely. | |
| 13:36:17 | bauzas | provided I'm clear on my spec | |
| 13:36:37 | stephenfin | sahid: So for 4 guest nodes, if it can fit 3 on one host node and 1 on the other, that would be OK | |
| 13:36:42 | bauzas | that, whatever logic I dislike on filter, it's not intended to be in Placement | |
| 13:36:56 | sahid | stephenfin: please don't do that | |
| 13:36:58 | efried | bauzas: Would even work if we wanted to support explicit sharding/anti-affinity - like I said earlier, the filter would be responsible for getting rid of the candidates where placement "incorrectly" clustered separate groups into the same RP. | |
| 13:37:03 | Shilpa | stephenfin: ok will check further, if i will get something, will let you know, thanks | |
| 13:37:04 | bauzas | ++ | |
| 13:37:06 | bauzas | efried: ++ | |
| 13:37:20 | efried | sahid: Please clarify. | |
| 13:37:21 | sahid | you are going to break the whole aim of numa toplogy | |
| 13:37:21 | stephenfin | sahid: But we're not breaking the NUMA affinity with PCI devices or the likes. At least one of those guest nodes would have to be placed on the same host NUMA node as the PCI device | |
| 13:37:39 | efried | sahid: You're saying that if we request 4 (host) nodes, we must get 4 (host) nodes? | |
| 13:37:45 | stephenfin | sahid: This is no different to what we do now | |
| 13:37:46 | sahid | yes | |
| 13:38:08 | mdbooth | The multiattach job seems to be unhappy today. Did I miss any traffic about that? | |
| 13:38:10 | efried | sahid: Yeah, bauzas pointed to the flavor docs earlier which strongly implied (to my understanding) that when I say 4, I mean "at most 4" | |
| 13:38:23 | efried | mdbooth: I was waiting for mriedem to arrive so I could pester him about that. | |
| 13:38:28 | stephenfin | sahid: If I have a guest with a PCI device and hw:numa_nodes=2, then only one guest NUMA node would be placed on the same node as the PCI device | |
| 13:38:33 | stephenfin | *same host nodes as | |
| 13:38:48 | stephenfin | sahid: Come to think of it, this would improve performance | |
| 13:38:51 | stephenfin | *could | |
| 13:38:52 | efried | mriedem: Here's an example: http://logs.openstack.org/49/560349/1/check/nova-multiattach/ce31aed/logs/screen-n-cpu.txt.gz?level=ERROR | |
| 13:38:56 | mdbooth | efried: Ok. I won't double-pester him, then :) | |
| 13:39:20 | sahid | stephenfin: again we should not accept the host | |
| 13:39:32 | sahid | we sould never break the guest numa topology | |
| 13:39:33 | stephenfin | sahid: e.g. if we could fit the two guest NUMA nodes on the same host NUMA node as the PCI device, we'd be guaranteeing affinity for all guest CPUs | |
| 13:39:33 | efried | mriedem: ...which looks kinda like something wrong in the CI env, not in the code. But I'm pretty ignorant in this realm. | |
| 13:39:36 | mriedem | did you guys try doing a logstash query to find out when that started and if it's just that job? | |
| 13:39:39 | stephenfin | as opposed to half of them | |
| 13:39:48 | mriedem | my guess would be it's related to https://review.openstack.org/#/c/554314/ | |
| 13:40:01 | stephenfin | "stephenfin: again we should not accept the host" what do you mean? | |
| 13:40:06 | efried | mriedem: See, this is why we ask you. | |
| 13:40:09 | sahid | as i have indicated it's all about performance and distance between cpu, memory channel and pci devices | |
| 13:40:13 | mdbooth | efried: Hehe | |
| 13:40:23 | efried | mriedem: You came up with that shit off the top of your head; it would have taken me years to figure out. | |
| 13:40:30 | sahid | you are going to break this affinity | |
| 13:40:32 | stephenfin | sahid: I don't think you're understanding what I'm saying | |
| 13:40:32 | mriedem | but i'll be gone some day | |
| 13:40:42 | sahid | stephenfin: re-reading, sorry | |
| 13:41:00 | stephenfin | sahid: Let's table this for discussion on the spec. I think bauzas has his answer for now :) | |
| 13:41:04 | mdbooth | Was about to say that looks like a platform error | |
| 13:41:08 | stephenfin | sahid: good talk! :) | |
| 13:41:23 | mriedem | efried: http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22Connection%20to%20libvirt%20failed%3A%20Failed%20to%20connect%20socket%20to%20'%2Fvar%2Frun%2Flibvirt%2Flibvirt-sock'%3A%20Permission%20denied%3A%20libvirtError%3A%20Failed%20to%20connect%20socket%20to%20'%2Fvar%2Frun%2Flibvirt%2Flibvirt-sock'%3A%20Permission%20denied%5C%22%20AND%20tags%3A%5C%22screen-n-cpu.txt%5C%22&from=7d | |
| 13:41:35 | sahid | stephenfin: sure | |
| 13:41:37 | mriedem | it's definitely due to that change, since it's just that job | |
| 13:42:06 | efried | stephenfin: I don't know if bauzas has his answer. The question was, "if the user asks for 4 nodes, do we gotta get exactly 4 nodes from the host, or is it okay if it's anywhere from 1..4?" | |
| 13:42:21 | efried | stephenfin: Before sahid chimed in, we thought "1..4 is fine" was the answer. | |
| 13:42:32 | efried | stephenfin: Now we don't know anymore. | |
| 13:42:45 | efried | stephenfin: And bauzas definitely needs that answer to do his next spec edit. | |
| 13:42:46 | mriedem | efried: i'm hoping that https://review.openstack.org/#/c/554317/ will handle it | |
| 13:43:19 | stephenfin | efried: Hmm, can we discuss that on the spec so I can write something longer. I'm clearly not doing a good job of explaining here | |
| 13:43:21 | efried | mriedem: But that guy is failing the same way http://logs.openstack.org/17/554317/3/check/nova-multiattach/fd35a93/logs/screen-n-cpu.txt.gz?level=ERROR | |
| 13:43:49 | stephenfin | and/or I'm missing what sahid is trying to say | |
| 13:44:01 | stephenfin | efried: bauzas can just choose one and we'll weigh in there | |
| 13:44:10 | efried | fair | |
| 13:47:19 | sahid | i just saying that our current behavior to handle numa topology for guests is right we should not consider ok a guest requesting 2 NUMA nodes fit on one host NUMA node | |
| 13:47:32 | mriedem | efried: i think this is the problem http://logs.openstack.org/17/554317/3/check/nova-multiattach/fd35a93/logs/devstacklog.txt.gz#_2018-04-11_18_10_24_388 | |