Earlier  
Posted Nick Remark
#openstack-nova - 2019-05-17
11:54:48 sean-k-mooney aspiers: ya maybe
11:55:03 sean-k-mooney it woudl depend on when it failed i guess
11:55:19 sean-k-mooney if we have not deleted it form the souce node yet then you should be fine
11:55:22 aspiers I think the idea was maybe that masakari could reinvoke the API in those circumstances
11:55:50 sean-k-mooney ya i think if the db says its still on the source node then you can evac again
11:55:57 aspiers but is there even a way to query the API for the state of an evacuate workflow?
11:56:15 sean-k-mooney but depending on the failure mode the vm could be paused/running on another node at that point
11:56:19 aspiers I vaguely remember that being discussed at past summits
11:56:30 aspiers yeah, the devil is in the details I guess
11:57:20 aspiers I don't think there's ever been enough corporate sponsorship from RH or SUSE to spend time really cleaning up all those corner cases
11:57:21 sean-k-mooney if your contol plane if failing you shoudl really stop what your doing and fix that first then go back to fixing your broken compute nodes
11:57:36 aspiers oh sure, that's a totally different kettle of fish
11:58:27 aspiers compute HA is impossible without a resilient control plane
11:58:49 aspiers same for most workflows
12:01:01 aspiers sean-k-mooney: mriedem makes a good point on https://review.opendev.org/#/c/643578/3//COMMIT_MSG that resurrect is an admin-only command, so "openstack server resurrect" could mislead non-admin users into thinking they can call it
12:01:42 aspiers OTOH I don't agree with his statement "evacuate moves the server to another host (actually it rebuilds it on another host)"
12:02:04 sean-k-mooney aspiers: migrate is an admin command too
12:02:13 sean-k-mooney and that is openstack server migrate
12:02:42 aspiers since a) you can't "move" a server which has already died, and b) it only rebuilds if it was using ephemeral storage
12:02:44 sean-k-mooney the only non admin migration is resize
12:03:01 aspiers sean-k-mooney: right, that's why he was suggesting nesting under "openstack server migrate"
12:03:07 sean-k-mooney no
12:03:17 sean-k-mooney migrate implies it will preserve you data
12:03:20 aspiers but I really don't like that cos resurrect is not a form of migration
12:03:27 sean-k-mooney so that would be worse then evac
12:03:41 aspiers yes, I think we are saying the same thing in different ways :)
12:04:18 sean-k-mooney what im saying is migrate is not an option because migrate implies we move data and we dont in the most common form for evac
12:04:29 sean-k-mooney most deployment have an ephermeal root disk
12:04:36 aspiers yes, that's one good reason to avoid migrate
12:04:50 aspiers and it's not the only one
12:05:44 aspiers at a higher level of abstraction, what you are saying could be reframed as "migrate" implies moving something from A to B without significantly changing it
12:05:51 sean-k-mooney we also discussed having two commands one that guarnetees it preserves your data and one tha that always destroys it
12:06:04 aspiers but you start with something dead on A, and end with something alive on B, that is a big change in state
12:06:12 sean-k-mooney e.g. recreate woudl always destoy any instance and recreate it loasing data
12:06:15 aspiers therefore does not deserve to be called a form of migration
12:07:02 artom Data destruction/preservation also depends on where said data is
12:07:10 aspiers sean-k-mooney: yeah that might be a good approach
12:07:10 sean-k-mooney openstack server migrate --evacuate would guarentte that your data was moved or would not try to do dit
12:07:36 aspiers I mean, having two different commands
12:07:48 aspiers but I don't like migrate --evacuate, for reasons just explained
12:08:04 aspiers I don't really like migrate --resurrect either
12:08:35 aspiers although it bothers me less than migrate --evacuate
12:09:40 aspiers "openstack server recreate" for the ephemeral case and "openstack server resurrect" for the shared storage case feels OK to me
12:09:50 openstackgerrit Surya Seetharaman proposed openstack/python-novaclient master: Allow passing negative values for the locked search_opt in server list https://review.opendev.org/659783
12:10:08 aspiers but I can see the concern around non-admin users expecting to be able to use it
12:10:49 sean-k-mooney aspiers: well wel could allow openstack server recreate to be non admin
12:11:40 sean-k-mooney its basically a rebuild but optionally to another host
12:12:20 aspiers sean-k-mooney: in what scenarios would non-admin users use that? not if the server is already running right? cos it reuses the old name
12:13:21 sean-k-mooney aspiers: i was implying that openstack server recreate would kill the server if it was running and rescudle it
12:13:28 aspiers oh
12:13:53 sean-k-mooney they would use it if the image or flavor had been updated and they wanted to create the sever with the updated version
12:14:07 sean-k-mooney but keep the same ports and data volumes
12:14:16 aspiers yeah I guess that could be useful
12:14:45 aspiers or if the instance got screwed up somehow, e.g. accidental rm -rf ;-)
12:15:18 sean-k-mooney yep if you instacne are vnfs it would be a neat way to do a software update
12:15:27 sean-k-mooney kindof like in k8s land
12:15:27 aspiers yep
12:15:45 sean-k-mooney e.g. just kill the pod and recreate with the latest version of it
12:17:54 aspiers right
12:18:21 aspiers so are you thinking to update https://review.opendev.org/#/c/643578 to split into two separate commands recreate/resurrect?
12:18:52 aspiers that would work for me, not sure what mriedem will think though
12:19:12 aspiers with both I'd prefer to avoid mentioning the word "migrate" anywhere
12:19:45 aspiers since "migrate" implies avoiding any significant change in state (except the location)
12:26:28 aspiers sean-k-mooney: BTW which timezone are you in?
12:26:52 aspiers I'm guessing somewhere in Ireland?
12:27:43 sean-k-mooney yes
12:27:57 sean-k-mooney im shannon on the west coast of ireland
12:27:59 aspiers nice
12:28:16 sean-k-mooney what timezone i am awake in is not alway the same as where im located
12:28:22 aspiers true for me too ;)
12:28:35 aspiers for some reason I still expect all nova devs to be in north america
12:28:54 aspiers I'm in London
12:29:32 openstackgerrit Gorka Eguileor proposed openstack/nova master: Use os-brick locking for volume attach and detach https://review.opendev.org/614190
12:29:41 aspiers got a lot of family in Dublin but never been further west than there yet :-(
13:15:54 efried kashyap, aspiers: what's up now?
13:16:06 kashyap efried: It's a change of scenery :-)
13:16:14 aspiers efried: ah, you missed the almight bike osc shed ;-)
13:16:19 kashyap efried: SEV-related, uncontroversial SEV-related
13:16:27 kashyap Err
13:16:31 aspiers oh, that too
13:16:34 kashyap "SEV-related, uncontroversial infra patch"
13:16:55 kashyap aspiers: That's what I assumed efried meant, when he pinged both of us together :D
13:17:01 efried I refer to ==> 3:45:56 AM - kashyap: aspiers: I think your change is ready to merge. Let's check with efried (or stephenfin) when they're about.
13:17:13 kashyap Yep, I correctly guessed.
13:17:13 aspiers yeah, that one
13:17:32 kashyap It is this one: https://review.opendev.org/#/c/655268/ -- "Add infrastructure for invoking libvirt's getDomainCapabilities API"
13:18:12 efried Okay. This isn't really in my, ahem, "domain" of expertise
13:18:15 efried but I'll take a look.
13:19:30 ganso melwitt, dansmith, tonyb: Hi! could you please review https://review.opendev.org/#/c/659338 when you have some time available? Thanks in advance! =)
13:19:44 aspiers efried: it should be pretty simple and not require special expertise
13:22:05 efried aspiers, kashyap: Does this also have to do with video models?
13:22:19 efried https://blueprints.launchpad.net/nova/+spec/libvirt-video-device-models
13:23:10 kashyap efried: No, that getDomainCapabilities() isn't related to video models.
13:23:15 efried ight
13:23:29 efried I see video models in your fake xml, so...
13:23:46 efried uh, I thought I did...
13:24:00 aspiers I guess it could be a future way of detecting available video models?
13:24:01 efried yeah, there. (Chrome's text search has been way slow for me lately)
13:24:08 aspiers if anything needed to do that
13:24:19 aspiers but that's certainly not what's driving the change right now

Earlier   Later