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#openstack-nova - 2018-04-12
13:30:00 bauzas sahid: he's just booting a flavor
13:30:17 bauzas but what he knows is that he'll get a guest having its own topology
13:30:20 openstackgerrit Matthew Booth proposed openstack/nova master: Rename recreate to evacuate in driver signatures https://review.openstack.org/560900
13:30:20 stephenfin Yeah, what bauzas said
13:30:33 sahid yes and if he wants 2 numa where don"t want to fake that
13:30:39 openstackgerrit Eric Fried proposed openstack/os-traits master: normalize_name helper https://review.openstack.org/560107
13:30:43 stephenfin He wants two _guest_ NUMA nodes
13:30:50 sahid yes and if he wants 2 numa nodes for it's guest we don"t want to fake that
13:31:00 stephenfin The entire thing is fake
13:31:14 bauzas sahid: so some evil guy could guess there are no left hosts having 2 numa nodes
13:31:20 stephenfin There aren't actually two guest NUMA nodes. That's just QEMU/KVM mocking it
13:32:07 sahid stephenfin: it's not... the guest memory and vcpus threads are running on a uniq node
13:32:35 stephenfin sahid: I get that. I'm not suggesting splitting a guest's NUMA node across a host NUMA node
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 openstackgerrit Andrey Volkov proposed openstack/osc-placement master: CLI allocation candidates (v1.10) https://review.openstack.org/514647
13:34:33 stephenfin And vSwitches :)
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]
13:34:34 openstackgerrit Andrey Volkov proposed openstack/osc-placement master: New dict format of allocations (v1.11, v1.12) https://review.openstack.org/542819
13:34:35 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 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
13:37:21 sahid you are going to break the whole aim of numa toplogy
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 efried mriedem: ...which looks kinda like something wrong in the CI env, not in the code. But I'm pretty ignorant in this realm.
13:39:33 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
13:39:36 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 mriedem but i'll be gone some day
13:40:32 stephenfin sahid: I don't think you're understanding what I'm saying
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

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