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#openstack-nova - 2020-09-03
14:51:57 sean-k-mooney that could be used for mdev for vgpus too if we wanted
14:52:10 sean-k-mooney it was created to be generic so we could reuse it
14:52:34 sean-k-mooney its currently only used for pmem
14:53:24 sean-k-mooney the pmem resouce are also not in the comptue nodes table unless they are embeed in say the host numa_toplogy bolb
14:53:55 sean-k-mooney unless i missed something
14:54:19 artom I don't have enough context, but maybe they don't need to be persisted in the DB?
14:54:43 artom Like, what does it affect? For scheduling, we only need to know quantities of mdevs, not individual ones, no?
14:55:00 sean-k-mooney we do but we use placement for the sechduling aspect
14:55:19 sean-k-mooney artom: for vGPUs you mean
14:55:25 artom sean-k-mooney, yeah, for example
14:55:42 artom Building the XML of new instances? Do we need to now the paths of available mdevs?
14:56:03 sean-k-mooney quantity and mdev_type which can be tracked via triats is enough in that specific case
14:56:25 sean-k-mooney artom: we need to create an mdev and put the path in the xml
14:56:41 artom So based on that seems like not tracking them was maybe the correct choice?
14:56:59 sean-k-mooney yes and no
14:57:11 sean-k-mooney it creates a depenency on the domain xmls for running guest
14:57:21 sean-k-mooney but it was doable without the db level tracking
14:57:26 sean-k-mooney so we did not modify the db
14:57:48 artom You mean for stuff like hard reboot?
14:57:58 openstackgerrit Pavlo Shchelokovskyy proposed openstack/nova master: Raise 409 when removing security group from instance https://review.opendev.org/735572
14:58:03 sean-k-mooney since we coudl rely on plamcnet for atomic claims of resouces we coudl skip doning that in nova
14:58:14 artom OTOH, it's not like vGPUs have state, so if it gets a different mdev after hard reboot, does it really matter?
14:58:35 artom sean-k-mooney, definitely agree with the general idea
14:58:36 sean-k-mooney if the mdev type does not change no
14:58:50 sean-k-mooney for pmem its much more important
14:59:03 sean-k-mooney which is why we now have https://github.com/openstack/nova/blob/c57d52e1978210fb3260bf8ea442237d548db576/nova/objects/resource.py
14:59:10 sean-k-mooney so that we can do this genericly
14:59:20 artom sean-k-mooney, ah, so for when it matters we *do* persist it in the DB
14:59:34 sean-k-mooney we do now yes
14:59:49 sean-k-mooney and we have a generic way to do it in the future without db modficiations
15:00:11 sean-k-mooney its one of the thing i pushed for durign the pmem stuff which alex_xu and other kindly implemented
15:01:22 artom sean-k-mooney, so yeah, NUMA in placement would be nice, and would solve a whole bunch of problems, but it's a mess to make work, so here we are ^_^
15:02:07 sean-k-mooney this really doesnt have that much to do with numa in placment although this generic resouce field would allow use to too remove teh numa blobs if we had that
15:02:42 sean-k-mooney we would still have to do the resouce tracking in the db using this but its an alternitive
15:02:59 sean-k-mooney im not sure its worth the work to move it
15:03:34 sean-k-mooney but for example if we start support vdpa devices in the futrue
15:03:55 sean-k-mooney i would proably look to use this or extend the pci tracker
15:04:19 sean-k-mooney (just the type filed)
15:04:40 sean-k-mooney but we should not need to modify the db to add support for vdpa
15:05:06 sean-k-mooney or if we wanted to add orther host device passhtough support like block devices or usb devices
15:05:16 sean-k-mooney the resouce filed can be used for that
15:07:15 sean-k-mooney the limitation is that to use it you have to frist track the resouce in placment
15:13:55 artom sean-k-mooney, yeah, I meant more in the general sense of "using placement for atomic resource tracking"
15:14:10 sean-k-mooney artom: well it will never actully do that
15:14:19 sean-k-mooney it will track capastity
15:14:24 sean-k-mooney but not indiviual resouces
15:14:25 artom sean-k-mooney, yeah, inventories
15:14:36 artom (In retrospect, maybe that was a mistake?)
15:14:50 sean-k-mooney it was a deliberate design choice
15:14:55 artom I know
15:15:07 sean-k-mooney we knew the concequece was the resouce tracker would alwys be needed for assignment
15:15:15 artom Just saying, maybe not the correct one to make - though obviously hindsight is 20/20, yadda yadda
15:15:48 openstackgerrit Merged openstack/nova stable/rocky: libvirt: Provide VIR_MIGRATE_PARAM_PERSIST_XML during live migration https://review.opendev.org/747975
15:15:51 sean-k-mooney it not a hignsight thing we knew the resouce treacker and some level of assignment logic woudl be needed in nova
15:16:03 openstackgerrit Merged openstack/nova stable/ussuri: Removed the host FQDN from the exception message https://review.opendev.org/749607
15:16:09 openstackgerrit Merged openstack/nova master: privsep: Add support for recursive chown, move_tree operations https://review.opendev.org/742864
15:16:57 sean-k-mooney to be clear we coudl use palcment for indeivigual resouce tracking if we wanted via nesting and many many more resouce providers
15:17:24 artom Eww
15:17:29 sean-k-mooney its flexable enough to do that but we chose not too
15:17:29 artom sean-k-mooney, anyways, it's all moot at this point
15:49:20 artom Whoever did that is awesome
15:53:45 gibi nova meeting starts in 6 minutes on openstack-meeting-3
16:00:18 lyarwood artom: it's great but I'd also love to write a script to open everything in vim (over http) using the raw links
16:01:02 artom lyarwood, ... everything?
16:01:04 sean-k-mooney lyarwood: i think lnav support direct links
16:01:31 sean-k-mooney it would automaticaly syntax highlith and alinge all the logs by time stamp too if that worked
16:02:44 lyarwood artom: well not everything but the stuff I typically look at, so n-* logs, tempest logs etc
16:02:59 sean-k-mooney anything ending in log
16:03:21 sean-k-mooney oh i guess most end in .txt
16:04:23 sean-k-mooney ah the gzip compression mess up usin lnav and likely vim with the raw urls
16:08:43 lyarwood sean-k-mooney: vim WORKSFORME with gzip FWIW
16:08:58 sean-k-mooney lyarwood: gzip is not the issue
16:09:09 sean-k-mooney https://storage.bhs.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/zuul_opendev_logs_557/746986/3/check/nova-live-migration/557b715/logs/screen-n-cpu.txt
16:09:17 sean-k-mooney us being served compressed
16:09:31 lyarwood ah yeah that borks vim
16:09:37 sean-k-mooney yep
16:10:01 sean-k-mooney vim and lnave are not reading the hearer or it is not serving it with the writh header
16:10:36 lyarwood I think vim just calls out to wget tbh
16:10:42 sean-k-mooney ya its being served tih text/plain and Content-encoding gzip
16:10:46 lyarwood at least it does for me but that could be a plugin
16:11:18 sean-k-mooney yep so lnav and vim would have to use teh Accepts-encode header to not allow copression
16:11:34 sean-k-mooney or read the respocne head and do the right thing
16:12:11 sean-k-mooney that said just localy donloadingthm to somewhere in /tmp and then passing the paths to vim or lnav works
16:31:36 openstackgerrit Stephen Finucane proposed openstack/nova master: Add reproducer for bug #1894095 https://review.opendev.org/749713
16:31:36 openstack bug 1894095 in OpenStack Compute (nova) "Running periodic task during live migration results in incorrect usage" [Medium,Confirmed] https://launchpad.net/bugs/1894095 - Assigned to Stephen Finucane (stephenfinucane)
16:37:09 gibi sean-k-mooney: can I pull the trigger on the os-vif release https://review.opendev.org/#/c/749535/ ?
16:40:48 artom lyarwood, so actually our volume thing with whitebox is different - it's a test for detaching a volume with libvirt stopped, so we expect the volume to remain in-use until libvirt starts up again and the detach completes. Did that behaviour change?
16:45:03 sean-k-mooney gibi: ya i think so
16:45:10 gibi sean-k-mooney: ack
16:45:21 sean-k-mooney the two patches i was waiting for are still not merged but they need rework
16:45:27 sean-k-mooney so we will just backport them later
16:45:32 gibi OK, done
16:45:35 lyarwood artom: when you say completes is the disk detached from the domain?
16:45:40 lyarwood artom: or just detached in cinder
16:46:14 artom lyarwood, cinder
16:46:19 lyarwood artom: if libvirt is stopped the call to detach should fail but AFAIK we should then rollback the volume state to in-use
16:46:27 lyarwood artom: if we don't that's a bug
16:47:00 artom lyarwood, ok, I'll dig some more then - looks like it's only happening with focal
16:47:09 artom For all I know we're stopping libvirt wrong :P
16:47:22 lyarwood huh, might be the error raised from the libvirt python lib has changed

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