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#openstack-nova - 2018-03-23
14:06:51 bauwser sean-k-mooney[m]: NUMA related things should be covered in https://review.openstack.org/#/c/552924/3/specs/rocky/approved/numa-topology-with-rps.rst
14:07:38 bauwser figleaf: I don't disagree with that statement
14:07:46 sean-k-mooney[m] figleaf: almost all server systems are numa system even systems with one socket
14:08:05 bauwser figleaf: I'm just trying to evaluate the operator impact of a NoValidHost if we begin counting NUMA nodes for non-NUMA specific instances
14:08:25 figleaf sean-k-mooney[m]: sure, but the choice on how to consume them (respecting NUMA, or ignoring) is an up-front decision by the operator.
14:08:38 sean-k-mooney[m] bauwser: i think it also needs to be in jays cpu resources spec
14:09:10 bauwser figleaf: so you agree with the fact that a classic flavor just asking for VCPUs shouldn't be accounting NUMA nodes, right?
14:09:28 sean-k-mooney[m] figleaf: no its a choice of the virt driver
14:09:36 bauwser how the inventory is modeled is one thing
14:09:53 bauwser and I'm fine with having VCPU resources on a NUMA node if that helps
14:09:57 figleaf bauwser: of course, but it would only select a host that was configured *not* to use NUMA. IOW, the ram, vcpu, etc, was inventory of the compute
14:10:15 bauwser but my point is, I don't want to get a NoValidHost if that restricts my existing flavor to specific NUMA nodes
14:10:51 openstackgerrit Merged openstack/nova master: Change compute mgr placement check to region_name https://review.openstack.org/554759
14:10:54 bauwser figleaf: that's super costly then
14:11:06 openstackgerrit Merged openstack/nova master: Remove translate and a TODO https://review.openstack.org/554827
14:11:07 figleaf bauwser: if you configure all your machines not to use NUMA, and request a NUMA-specific flavor, you will get NoValidHost. The reverse would also be true
14:11:20 bauwser figleaf: because I want to have both compute workloads that can do NUMA affinity and regular workloads that don't care
14:11:42 bauwser figleaf: again, that's a huuuuuge behavioural change
14:11:50 figleaf bauwser: sure, then configure some of your machines for NUMA, and others for not-NUMA
14:11:58 figleaf The balance is up to the operator
14:11:58 bauwser it's suboptimal
14:12:09 sean-k-mooney[m] figleaf: we don't have a compute node option for ignore numa
14:12:27 cdent making the optimal solution is introducing an enormous amount of complexity that is making hard to finish _any_ solution
14:12:28 bauwser sean-k-mooney[m]: I guess figleaf wants it
14:12:46 sean-k-mooney[m] Figleaf but that is not something you can configure normally
14:12:53 bauwser if you opt for non-NUMA, then you get a flat inventoty
14:13:14 bauwser if you opt for NUMA topology, then you're stuck with NUMA-only workloads on that single node
14:13:34 bauwser :/
14:14:04 figleaf sean-k-mooney[m]: it would be how resources are reported. If the virt driver reports that a NUMA node owns some inventory, then that NUMA node has to satisfy the request. There is no concept in placement for the kind of sharing you're talking about
14:14:05 bauwser cdent: that's the whole purpose of the spec
14:14:28 cdent bauwser: which "that's"?
14:14:30 openstackgerrit Jay Pipes proposed openstack/nova-specs master: Standardize CPU resource tracking https://review.openstack.org/555081
14:14:34 bauwser cdent: to see if we can model the NUMA inventories in any other ways that would help to solve the problem without requiring too much engineering
14:15:06 leakypipes cfriesen, bauwser, sahid, sean-k-mooney[m], finucannot, fried_rice: ^^ ok, new revision pushed. lemme know if that looks a bit better.
14:15:11 sean-k-mooney[m] figleaf: again how would yo do that. Numa is a feature of the hardware its not a software option so your talking about ordering hardware with out multiple memory controllers or configure mirrors dimms in the bios
14:15:18 bauwser leakypipes: you missed a NUMA conversation
14:15:31 cdent bauwser: okay. My statement was more along the lines of "trying to satisfy all this NUMA and other enhanced platform stuff, in general, is breaking the 80/20 rule"
14:15:55 leakypipes bauwser: not really. see the spec. :)
14:16:00 bauwser cdent: the problem is that like sean-k-mooney[m] said, modern architectures are NUMA-based, but 80% of our workloads don't care
14:16:13 sean-k-mooney[m] figleaf: not in placement but that is how nova works today.
14:16:33 sean-k-mooney[m] leakypipes: cool will do
14:16:36 bauwser leakypipes: hah, teaser!
14:16:37 openstackgerrit Merged openstack/nova master: Add the version description for InstanceActionEventList https://review.openstack.org/555711
14:16:39 bauwser I like that
14:16:53 sean-k-mooney[m] Lleakypipes yes this is related to that spec too
14:17:14 figleaf sean-k-mooney[m]: it is software that reports what hardware exists to placement. If it configure to respect the NUMA layout, it reports the inventory that NUMA nodes "own". If it is configured to sum up the resources, then it reports inventory of the compute node.
14:17:17 bauwser I quote "placement is the most ambitious crossover of the history"
14:18:02 sean-k-mooney[m] cdent: well in this case we are breaking insance that dont care about numa by fitting them to numa nodes
14:19:13 bauwser leakypipes: https://twitter.com/sylvainbauza/status/977187898167611392
14:20:34 giblet bauwser: lol
14:21:18 openstackgerrit Merged openstack/nova master: remove _cleanup_running_deleted_instances repeat detach volume https://review.openstack.org/554090
14:21:34 openstackgerrit Merged openstack/nova master: deprecate fping_path config option https://review.openstack.org/526602
14:22:09 mriedem there is no reason we need to warn for this right? http://git.openstack.org/cgit/openstack/nova/tree/nova/compute/manager.py#n3340
14:22:22 mriedem the user is trying to do something the api allows them to do, so the operator shouldn't be warned about it
14:22:46 mriedem https://git.openstack.org/cgit/openstack/nova/tree/nova/compute/api.py#n2717
14:22:51 bauwser I think it's time for me writing a new rev' for NUMA and stating the concerns in the spexc
14:25:07 cdent my laptop battery and my brain battery are dying
14:26:13 bauwser cdent: take a power bank
14:26:31 cdent bauwser: you got one for brains? hook me up
14:26:33 bauwser cdent: that said, I can't perclue where to plug the bank
14:27:35 bauwser s/perclue/guess
14:28:03 bauwser note for self, stop buying expensive nespresso machines that are just subject to failures
14:28:23 bauwser and start finding other ways for making coffee
14:29:58 openstackgerrit Tyler Blakeslee proposed openstack/nova master: Add __repr__ for NovaException https://review.openstack.org/555812
14:31:35 openstackgerrit Surya Seetharaman proposed openstack/nova master: Allow scheduling only to enabled cells (Filter Scheduler) https://review.openstack.org/550527
14:31:36 openstackgerrit Surya Seetharaman proposed openstack/nova master: Modify nova-manage cell_v2 list_cells to display "disabled" column https://review.openstack.org/555415
14:31:36 openstackgerrit Surya Seetharaman proposed openstack/nova master: Add --enable and --disable options to nova-manage update_cell https://review.openstack.org/555416
14:31:37 openstackgerrit Surya Seetharaman proposed openstack/nova master: Add disabled option to create_cell command https://review.openstack.org/555417
14:35:20 sahid leakypipes: ++ on you spec cpu-resources
14:38:51 bauwser leakypipes: time for a question ?
14:39:14 bauwser leakypipes: about https://review.openstack.org/#/c/555081/3/specs/rocky/approved/cpu-resources.rst@249 and beyond
14:39:32 leakypipes bauwser: sure
14:39:39 leakypipes sahid: +2 on tx/rx
14:39:47 bauwser leakypipes: just noting a few things on the spec
14:39:47 leakypipes sahid: I will let mriedem +W it though
14:40:04 bauwser leakypipes: sahid: the TX/RX was next in my review queue
14:40:05 superdan leakypipes: mriedem said he was leaving it to us in the meeting, so I think you can +W
14:40:14 bauwser I have a fucking low number of reviews this week
14:40:55 leakypipes superdan: got it. done.
14:41:19 leakypipes bauwser: reading specs takes a long time...
14:41:28 sahid superdan thanks for having so active on it
14:41:42 superdan sahid: s/having/being/
14:41:50 leakypipes :)
14:41:52 sahid :)
14:44:40 mriedem kashyap: i updated https://wiki.openstack.org/wiki/LibvirtDistroSupportMatrix for queens and added the ubuntu 18.04 LTS package versions based on https://packages.ubuntu.com/bionic/allpackages
14:44:46 figleaf leakypipes: quick question about the spec. When there are NUMA nodes with V/PCPU inventory, and a non-granular request is received, will there be allocation candidates returned for every possible combination of NUMA providers?
14:44:48 mriedem looks like all of the other distros in that table are old
14:45:00 kashyap mriedem: Ah-ha. I have it open in one tab
14:45:11 kashyap And was reviewing your historical changes there yesterday
14:45:17 mriedem kashyap: so since we didn't bump in queens,
14:45:18 kashyap Will get to it, once I respond to this bug-from-hell downstream
14:45:35 mriedem we already have a 'next min version' in the driver, which is actually kind of old now, libvirt 1.3.1
14:45:37 leakypipes figleaf: yes, alloc candidates would contain alloc requests against each NUMA node that had space to fit the sum amount of requested VCPU/PCPU
14:45:48 mriedem the question is then what will the next min version be in Solar
14:45:53 kashyap What is Solar?
14:45:54 leakypipes figleaf: I can add a note to clarify that.
14:45:57 kashyap A new Ubuntu version?
14:46:01 mriedem solar is next openstack
14:46:12 mriedem (pending that name is approved by legal)
14:46:15 kashyap Aah, I didn't check the release naming for the next one

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