| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2018-12-05 | |||
| 17:37:22 | mriedem | today we default to send both, versioned and unversioned, which kills rpc | |
| 17:37:27 | mriedem | s/kills/doesn't help/ | |
| 17:37:39 | mriedem | if nothing is consuming versioned yet, then that is a shitty default imo | |
| 17:38:02 | mriedem | i know we want to get people off the old stuff, but no one is doing that | |
| 17:38:18 | sean-k-mooney | ya just readign that makes sense but im kind of reluctent to default to old | |
| 17:38:32 | mriedem | and honestly without a schema that consumers can use, it's probably not really something they care about | |
| 17:38:37 | mriedem | since they can't do version negotiation | |
| 17:39:27 | sean-k-mooney | can we default to versioned going forward instead and tell peopel to enable both/unversions if they have a service that uses them? | |
| 17:39:45 | mriedem | we can do whatever | |
| 17:40:00 | mriedem | me? i'm going to go make lunch and try to think about something else. | |
| 17:40:21 | sean-k-mooney | ok :) | |
| 17:54:19 | cfriesen | sean-k-mooney: I replied to your comments on https://review.openstack.org/#/c/620959/ | |
| 17:55:33 | sean-k-mooney | cfriesen: yep i know the feature flags are already in placement but they currently mean find ma a host wtih X not enable X on the vm | |
| 17:55:53 | sean-k-mooney | cfriesen: qemu does not always requrie the host to have X to enable X for the guest | |
| 17:56:27 | sean-k-mooney | AVX is an exampel you can enable AVX in a guest as long as the host has SSE4 suport | |
| 17:56:28 | cfriesen | sean-k-mooney: not quite true. according to the spec the exposed traits represent the features of the CPU model that you would get in the guest. | |
| 17:57:01 | sean-k-mooney | the new spec | |
| 17:57:20 | cfriesen | In https://specs.openstack.org/openstack/nova-specs/specs/rocky/implemented/report-cpu-features-as-traits.html it says "The libvirt virt-driver should only return the CPU features which are available to the guest." | |
| 17:57:49 | sean-k-mooney | cfriesen: we currently report all cpu feature on the host i belive | |
| 17:58:00 | sean-k-mooney | i dont think we filter by the configured cpu model | |
| 17:59:15 | cfriesen | sean-k-mooney: see _get_cpu_traits() in virt/libvirt/driver.py | |
| 17:59:28 | openstackgerrit | Merged openstack/nova master: Add a bug tag for nova doc https://review.openstack.org/619434 | |
| 18:00:24 | cfriesen | sean-k-mooney: "if mode is 'custom', use cpu_model to generate CPU features" | |
| 18:02:28 | sean-k-mooney | when the traits were defiend in os tratis they were ment to model the host capablity though | |
| 18:02:32 | cfriesen | so on x86-64 specifying a trait currently *should* result in a guest with the specified CPU feature present, as far as I can tell | |
| 18:02:55 | sean-k-mooney | cfriesen: that seams to be the case but that was not the intent of the trait | |
| 18:02:59 | cfriesen | why would you care whether a host has a feature if you can't get it in the guest? | |
| 18:03:27 | sean-k-mooney | the trait was ment to allow you to ensure it was not emulated in software | |
| 18:04:11 | sean-k-mooney | the way it currently works i could get avx emulated in software using sse4 which will allow the application to run but will have worese perfromance | |
| 18:04:17 | cfriesen | so I guess you'd need to still use the ComputeCapabilitiesFilter for that? | |
| 18:04:34 | cfriesen | combine that with requesting the trait in the flavor, and you'd get both, no? | |
| 18:06:00 | sean-k-mooney | it still misses the point that HW_CPU_X86_AVX is ment to only be used if the host support it in hardware | |
| 18:07:22 | cfriesen | sean-k-mooney: if ComputeCapabilitiesFilter fails hosts that don't have it in hardware, and specifying the trait requests that it's available in the guest, that seems like it'd work. | |
| 18:07:49 | cfriesen | The other option is to simply not specify CPU models with features unsupported by your hardware...which is up to the operator. | |
| 18:08:11 | sean-k-mooney | it would work but i realy dislike that we are not useing the HW e.g. hardware namespace to model only hardware things | |
| 18:08:22 | cfriesen | sean-k-mooney: have you got any specs/docs for the intent of the trait? | |
| 18:09:41 | sean-k-mooney | that was my intent when i asked for namespacing in os traits https://github.com/openstack/os-traits/commit/23d81d4451dd29c23150b29b8fa9d3025ee8878f#diff-f290aedb8b7fdc21b2b04be76222f6c3 | |
| 18:10:23 | sean-k-mooney | the HW namespace was for hardware features | |
| 18:10:42 | cfriesen | we use the "hw" namespace for all sorts of virtual hardware stuff | |
| 18:11:10 | sean-k-mooney | we only started doing that this cylce with the vtpm spec | |
| 18:11:12 | cfriesen | number of numa nodes, cpu distribution between numa nodes, etc | |
| 18:11:19 | cfriesen | oh, you mean for trait | |
| 18:11:23 | sean-k-mooney | yes | |
| 18:12:10 | sean-k-mooney | anyway looks like we approved and implmented https://specs.openstack.org/openstack/nova-specs/specs/rocky/implemented/report-cpu-features-as-traits.html#libvirt so we are stuck with it | |
| 18:13:04 | sean-k-mooney | i was hopping not to make the same mistakes we did with flavors in os-traits but if i can rely on traits to modele this correctly i will always need filters | |
| 18:13:16 | cfriesen | I think it'd be worth adding something to the release notes warning operators to consider this when adding CPU models to the list. | |
| 18:13:55 | cfriesen | In practice, I would expect that most operators advertising high-performance would not want emulated features, no? | |
| 18:14:16 | sean-k-mooney | ya or better to the config option so its in the docs for setting the models/extra flags | |
| 18:14:27 | cfriesen | right, that makes sense | |
| 18:14:51 | sean-k-mooney | cfriesen: yes but as a tenat i can no longer rely on it being a hardware feature in a public cloud | |
| 18:15:15 | sean-k-mooney | i get the opertor usecase but this originally came form the mano folks | |
| 18:15:51 | cfriesen | gotta run for lunch | |
| 18:15:59 | sean-k-mooney | o/ | |
| 18:16:08 | sean-k-mooney | ill comment back on the spec. | |
| 18:16:21 | sean-k-mooney | since we are already missuing them wwe might as well continue | |
| 18:45:17 | openstackgerrit | Matt Riedemann proposed openstack/nova-specs master: Per aggregate scheduling weight (spec) https://review.openstack.org/599308 | |
| 18:46:35 | mriedem_away | johnthetubaguy: bauzas: ^ when you're around, i'm +2 on ^ now - seems like a good compromise from the per-flavor weights it started from | |
| 18:46:49 | mriedem_away | mgagne_: since you said you had something like this downstream already ^ it would be good if you can ack that works for you as well | |
| 18:52:31 | mgagne_ | mriedem: done. thanks | |
| 19:32:06 | openstackgerrit | Jack Ding proposed openstack/nova master: Preserve UEFI NVRAM variable store https://review.openstack.org/621646 | |
| 21:09:26 | efried | jaypipes, mriedem: Are you waiting for CERN to deploy on ironic nodes before reviewing series at https://review.openstack.org/#/c/615677/ ? | |
| 21:10:56 | mriedem | efried: not really | |
| 21:11:02 | mriedem | i'm not intentionally avoiding it | |
| 21:11:34 | efried | Cool, I know you're stretched pretty thin. | |
| 21:11:46 | mriedem | but my waist line continues to grow | |
| 21:13:57 | mriedem | here is an easy gate related fix https://review.openstack.org/#/c/623011/ | |
| 21:15:40 | mriedem | efried: i've been ignoring some other stuff for awhile so trying to burn that list down first | |
| 21:15:49 | mriedem | reviewing your series will be my xmas gift to you | |
| 21:15:52 | efried | mriedem: +2 on the tempest timeout | |
| 21:15:54 | mriedem | thanks | |
| 21:15:56 | efried | Thanks :) | |
| 21:38:38 | efried | mriedem: reserved=total for which resource? And how do you stop the virt driver from overwriting that? (Re ML post about CERN workaround for low alloc candidates limit) | |
| 21:40:24 | mriedem | VCPU? all of them? | |
| 21:40:27 | dansmith | for the compute node | |
| 21:40:35 | dansmith | for all of them yeah | |
| 21:40:57 | mriedem | the compute would probably need to know if it's service is disabled and if so, not ovewrite it | |
| 21:41:04 | dansmith | mriedem: I think we discussed just having an rpc cast to compute to have it do it, vs. a periodic | |
| 21:41:04 | mriedem | *its | |
| 21:41:22 | mriedem | dansmith: sure, but the next update_available_resource periodic would overwrite it | |
| 21:41:30 | mriedem | when reporting inventory | |
| 21:41:34 | dansmith | the compute can stop calling the virt driver's update method if it's disabled I would think | |
| 21:41:36 | sean-k-mooney | efried: the virt dirver really should not be touching the reserved value excpet when its first creating the RP | |
| 21:41:46 | mriedem | sean-k-mooney: the ironic driver does all the time | |
| 21:41:49 | dansmith | sean-k-mooney: uh, why? | |
| 21:41:49 | mriedem | when the node is being cleaned | |
| 21:41:57 | dansmith | the reserved amount is owned by the virt driver, IMHO | |
| 21:42:02 | mriedem | that's exactly why the placement api change was made so that reserved can equal total | |
| 21:42:04 | dansmith | only the virt driver knows what it should be | |
| 21:42:25 | sean-k-mooney | dansmith: well for the same reason as teh have the cpu allocation ratios vs inital cpu allocation ratios spec | |
| 21:42:28 | efried | agreed, all the inventory values ought to be owned by the virt driver, period. We start making exceptions, we end up with messes like allocation ratio... and reserved. | |
| 21:42:36 | sean-k-mooney | controling via api or config | |
| 21:42:57 | efried | but making that contract stick for this kind of workaround is going to be tricksy. | |
| 21:42:58 | dansmith | sean-k-mooney: that's not an example that helps your case I think :) | |
| 21:43:24 | mriedem | the alternative was a trait i think | |
| 21:43:32 | mriedem | and a pre-request placement filter in nova-scheduler | |
| 21:43:32 | efried | unless we do it with a handy-dandy provider config yaml file https://review.openstack.org/#/c/612497/ | |
| 21:43:35 | mriedem | or something like that | |
| 21:43:51 | mriedem | this isn't blues clues | |
| 21:43:55 | dansmith | mriedem: yeah, that's also an option | |
| 21:44:28 | mriedem | so api sets a trait (or removes it), virt doesn't overwrite it, and scheduler filters on it (essentially it becomes the ComputeFilter) | |