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#openstack-nova - 2017-05-24
16:01:50 jmlowe rerunning mapping
16:01:54 mriedem savvas: ok can you reply to the question i put in the commit messagE?
16:02:32 mriedem savvas: i.e. the volume gets created successfully but in the default 'nova' AZ,
16:02:44 mriedem which is different from the explicit non-default AZ that the instance is in,
16:02:47 mriedem and that's the bug, right?
16:02:51 mriedem but the boot request doesn't actually fail?
16:03:31 savvas no the boot request is accepted, it then tries to create a volume in AZ nova (default), when it fails it removes the attempted volume creation and leaves the new instance in error state
16:04:05 mriedem savvas: so is nova actually passing availability_zone='nova' to cinder when creating the volume?
16:04:08 mriedem or None?
16:04:33 savvas I believe it selects nova for it not being defined, but I can't tell for sure
16:04:37 mriedem edleafe: in the absence of bauzas, can a compute host live in more than one AZ?
16:04:47 savvas I've been using openstack for a week so I am still finding my way ;)
16:04:53 mriedem savvas: that's kind of important, because if nova is passing az=None then it's a different issue
16:04:58 mriedem savvas: you're a pro now
16:05:00 mriedem congratulations
16:05:01 edleafe mriedem: nope
16:05:25 mriedem ok, but a compute host can be in more than one host aggregate
16:05:29 mriedem that's where i get confused
16:05:30 edleafe sure
16:05:40 edleafe yes, it's very terrible
16:05:55 mriedem https://docs.openstack.org/developer/nova/aggregates.html
16:05:59 mriedem "one host can be in multiple aggregates, but it can only be in one availability zone"
16:06:03 mriedem i guess i should have read the manual
16:06:28 savvas mriedem: | OS-EXT-AZ:availability_zone |
16:06:33 savvas it leaves the zone empty when not defined
16:06:40 savvas so it doesn't explicitly pass on nova
16:07:19 mriedem savvas: ok so i don't see why the volume creation fails then
16:07:30 mriedem if nova isn't passing an AZ, cinder will create the volume in it's default AZ, which is 'nova'
16:08:01 mriedem i can see why / how the instance and volume can get into different AZs here, which is a bug
16:08:05 savvas mriedem: exactly, I don't have any cinder-volumes available in nova though
16:08:36 savvas right now I have 3 hypervisors setup in my test environment, all 3 in separate aggregates with separate storage zones
16:08:45 savvas in my case it looks like this:
16:08:55 savvas host-aggregate hv01-zone, has 1 member, hv01
16:09:05 savvas cinder on hv01 has storage/default zone set to hv01-zone
16:09:16 savvas and I follow the same structure for hv02 and hv03
16:09:32 savvas but the default nova group has no usable cinder volumes available in my setup
16:09:45 savvas so when the AZ is not defined, it fails
16:10:12 mriedem are you setting storage_availability_zone in cinder.conf on your 3 storage nodes?
16:10:54 mriedem i don't really know how cinder handles the AZs on their side
16:11:07 mriedem so i don't know what the actual error looks like when creating the volume on the cinder side,
16:11:13 mriedem if you have those details you could put them in that bug
16:12:00 savvas mriedem: yes, they are all on all 3 nodes
16:12:01 jmlowe ok, looking much better
16:12:18 mriedem jmlowe: sweet
16:12:32 mriedem rpodolyaka: can you explain where we fail with https://review.openstack.org/#/c/366724/ during boot?
16:12:35 mriedem is it during attach?
16:13:04 mriedem savvas: the volume gets created successfully though right? but then something else fails?
16:15:36 savvas mriedem: when the AZ upon instance creation is defined, yes. When the AZ upon instance creation is not defined, then no. When I create a volume manually via the CLI in the nova zone (so create a volume without defining AZ), it creates just fine
16:15:37 mriedem i think i see it
16:15:49 jmlowe I blame my complete lack of reading comprehension on my new monitor where the text is all very small and cannot be increased lest it injure my pride
16:16:28 savvas mriedem: let me correct that, the creation fails, sorry it accepts the command but it fails to create
16:16:28 mriedem jmlowe: so now that you've gone through this, it would be interesting to know which docs you read before you started upgrading
16:16:43 mriedem savvas: i think it fails here https://github.com/openstack/nova/blob/master/nova/virt/block_device.py#L368
16:16:48 savvas which in my opinion is logical behavior since there are no cinder-volume services running in the nova zone
16:16:59 jmlowe I half read this https://docs.openstack.org/releasenotes/nova/newton.html
16:17:23 mriedem jmlowe: did you see any of https://docs.openstack.org/developer/nova/cells.html#upgrade-minimal ?
16:17:32 jmlowe wasn't really thinking about what I was doing, was irritated by the cells0 db missing warning from nova-manage db sync
16:18:03 mriedem ^ is really the page with the basic instructions on upgrading to cells v2
16:18:20 mriedem so it'd be good info to know if people aren't aware of it, or it doesn't make sense in some parts, or there are things missing
16:18:25 jmlowe no, and that warning about the db name would definitely save me some headaches
16:18:42 mriedem which warning?
16:18:46 mriedem oh i see
16:18:47 mriedem in the doc
16:19:12 mriedem yeah, so simple_cell_setup defaulting the cell0 db name to nova_api_cell0 is a bug
16:19:13 savvas mriedem: I don't think so but i could be mistaken. To me it looks like a bug in determining where to deploy. If you explicitly define a zone, it will grab the right storage az. If you don't define a zone, it will grab an available HV AZ but it won't grab its corresponding available storage az
16:19:43 jmlowe so I'm still a little concerned that my transport_url for cell0 is none:///
16:19:59 jmlowe is that really not a problem?
16:20:00 dansmith jmlowe: yeah, that's wrong
16:20:11 dansmith jmlowe: you'll fail when some instance doesn't schedule if tat
16:20:25 dansmith jmlowe: but you don't need to do anything other than fix that record at this point.. no need to remap or anything
16:20:34 dansmith oh
16:20:35 dansmith sorry
16:20:36 dansmith transport_url
16:20:40 mriedem that's normal
16:20:44 dansmith yeah, there's no transport for cell0
16:20:48 dansmith yeah sorry, was thinking database
16:21:00 mriedem cell0 is a db which is a graveyard for instances that failed to schedule
16:21:19 jmlowe ah, ok that makes more sense
16:21:33 mriedem maybe, "Why is the transport_url for cell0 none:/// ?" should be in the FAQs
16:22:18 mriedem savvas: i've asked in https://review.openstack.org/#/c/366724/ which is the current proposed fix for the bug,
16:22:35 mriedem at this point i really need a clear idea of what the actual failure is, either in reply to that question in the patch or in the bug report
16:22:41 mriedem but we're kind of going in circle
16:22:44 mriedem *circles
16:23:17 mriedem i understand there is a problem, but i'd like to make sure i understand the problem before reviewing a fix, and i'd also like to consider some integration testing for this since it's complicated
16:27:15 savvas mriedem: alright let me see how I can get a more conclusive answer for you
16:33:25 mriedem jmlowe: btw i'm sort of working on backporting that cell0 db name fix to newton https://review.openstack.org/#/c/420461/ but it gets a bit complicated, and at this point i'm not sure if it helps anyone or not, but i'd surely like to help avoid people from falling into this trap in the first place where they have a nova_api_cell0 db in newton and then need to rename that to nova_cell0 in ocata
16:33:38 savvas mriedem: in my cinder scheduler log I caught this : default default] No weighed backend found for volume with properties: None.
16:33:52 savvas after attempting to create an instance without defining the AZ
16:34:29 savvas so nova passed on the None value for the AZ to cinder I guess
16:34:44 mriedem jmlowe: thoughts on that? would that at least be helpful to give people in the operators ML a heads up?
16:35:20 mriedem savvas: right and i'm saying that's no different from the case that cross_az_attach=True, which is why i don't think it would result in the volume create failing
16:35:28 mriedem so i think there is something else happening
16:36:48 savvas mmm, any thoughts as to where I should be looking? I've been tailing the nova and cinder logs to see what happens when I call for a nova boot
16:38:33 savvas mriedem: either way, I'll keep working on it, if I find anything useful I'll be sure to let you know. Thanks for your time!
16:39:41 mriedem savvas: if the instance goes to error state, it's mostly likely something failing in the nova-compute logs
16:41:27 savvas mriedem: ye from those logs I only find the error I initially reported: BuildAbortException: Build of instance 9484f5a7-3198-47ff-b728-178515a26277 aborted: Block Device Mapping is Invalid.
16:42:11 mriedem savvas: ok i think that's resulting from https://github.com/openstack/nova/blob/81bdbd0b50aeac9a677a0cef9001081008a2c407/nova/virt/block_device.py#L368
16:42:53 mriedem savvas: don't you see a traceback from here? https://github.com/openstack/nova/blob/81bdbd0b50aeac9a677a0cef9001081008a2c407/nova/compute/manager.py#L1593
16:43:28 mriedem wow i guess we really don't try to help out with the error message in this ase
16:43:29 mriedem *Case

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