| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2019-04-02 | |||
| 21:30:27 | mriedem | that's my guess anyway | |
| 21:30:27 | NewBruce | Aha…. | |
| 21:30:36 | NewBruce | ok, so can we override that? | |
| 21:31:43 | NewBruce | again, mnaser / sean-k-mooney suggested that might be the case and to upgrade the entire compute - which we were in the process of, however anothe error in a node caused a bit of strife due to broken libevent so’s in OVS so we halted | |
| 21:32:06 | mriedem | well you can pin the compute rpc api version to a specific release (queens) or even rpc api version (5.0) but that could break things where the controller is sending versions of objects to older queens computes that won't understand those chnages | |
| 21:32:11 | NewBruce | also, we have other sites where we have performed the same procedure, without issue | |
| 21:32:37 | mriedem | ultimately it looks like https://github.com/openstack/nova/blob/stable/rocky/nova/conductor/tasks/live_migrate.py#L41 is faulty in that it doesn't account for pinned RPC versions | |
| 21:32:39 | NewBruce | i have a test machine, so i can override to at least test it | |
| 21:32:40 | mriedem | dansmith: yeah ^? | |
| 21:33:03 | mriedem | NewBruce: the kill switch would be to disable the 'Port Bindings Extended' neutron API extension until you're fully upgraded to rocky | |
| 21:33:08 | dansmith | mriedem: if conductor is new enough then the new objects are fine | |
| 21:33:23 | NewBruce | which would force into the old flow | |
| 21:33:24 | mriedem | dansmith: sounds like conductor in this case is rocky but some computes are queens | |
| 21:33:31 | dansmith | mriedem: which is fine | |
| 21:33:36 | NewBruce | dansmith correct | |
| 21:33:37 | mriedem | because of the bounce back thingy? | |
| 21:33:40 | dansmith | yes | |
| 21:33:46 | dansmith | the rpc pin has nothing to do with the objects | |
| 21:33:54 | dansmith | it's only really method signatures | |
| 21:33:55 | mriedem | sure | |
| 21:34:01 | mriedem | but, | |
| 21:34:16 | mriedem | conductor is doing some stuff in neutron based on what the compute service versions are, | |
| 21:34:28 | mriedem | and then setting fields in the objects that get passed to compute, | |
| 21:34:42 | mriedem | and then compute has logic that is based on if those new fields are set or not, | |
| 21:34:45 | mriedem | which it sounds like they might not be | |
| 21:35:18 | mriedem | tldr compute is probably not doing the right thing | |
| 21:35:58 | dansmith | well, if the backport is right then it should be okay, unless the conductor is doing something against neutron that the compute can't possibly handle properly | |
| 21:36:02 | dansmith | but if so, we broke upgrades | |
| 21:38:13 | mriedem | mnaser: did you hit https://bugs.launchpad.net/nova/+bug/1822884 when upgrading to rocky and doing live migrations with mixed computes (queens and rocky?) | |
| 21:38:14 | openstack | Launchpad bug 1822884 in OpenStack Compute (nova) "live migration fails due to port binding duplicate key entry in post_live_migrate" [Undecided,New] | |
| 21:38:24 | mriedem | mnaser: or do you upgrade neutron after nova? | |
| 21:38:40 | mnaser | we upgrade neutron after nova usually mriedem | |
| 21:38:55 | mnaser | I’m very intimately familiar with that bug though. | |
| 21:39:03 | mriedem | first i've heard of it :/ | |
| 21:39:15 | mriedem | mnaser: ok but that's why you didn't hit it | |
| 21:39:21 | mnaser | I’ve been trying to help NewBruce nail it down forever. | |
| 21:39:36 | mnaser | But I’ve kinda struggled at finding the code path to replicate it | |
| 21:40:01 | mnaser | There are other environments where there is mixed compute AND Rocky network and this doesn’t happen | |
| 21:40:04 | mnaser | Right NewBruce ? | |
| 21:40:27 | NewBruce | yeah thats right mnaser | |
| 21:40:29 | mriedem | right he said, "2. OSA -> OSA uses the new flow (two entries which are cleaned up)" | |
| 21:40:40 | NewBruce | this is the first site we’ve seen it on... | |
| 21:41:43 | NewBruce | mriedem right; so if i grab a VM on an OSA node, and migrate it to an OSA node, watch ml2_port_bindings - ill see one port, briefly two ports, the profiles change, and then the second port entry removed | |
| 21:41:50 | NewBruce | as described in the bluebrint | |
| 21:42:23 | NewBruce | testing RDO - RDO, i don’t see that behaviour - just a single port entry in ml2_port_bindings throughout the entire migration | |
| 21:42:28 | mnaser | mriedem: NewBruce runs a few regions and this one is the only one where it works. With both queens to queens | |
| 21:42:41 | mnaser | Shit, what’s upgrade levels set to in the rdo notes? | |
| 21:42:57 | mnaser | Nodes | |
| 21:43:01 | mnaser | Sorry. I’m on mobile. | |
| 21:43:13 | NewBruce | mnaser auto | |
| 21:43:38 | NewBruce | mriedem and i chatted above that will pin it to the lowest version, as you suspected previously | |
| 21:43:41 | mnaser | ok, so yeah, I’m pretty torn on why it would actually do that in one environment and not another. | |
| 21:43:46 | mriedem | "all control nodes and net nodes are running OSA (Rocky), some compute are running RDO (Queens), some are RDO (Rocky) and the remaining are OSA (Rocky)." | |
| 21:44:01 | NewBruce | ill double check some other regions and see if they are diferent there | |
| 21:44:13 | mnaser | NewBruce: by any chance maybe the other regions aren’t pinned to lower version maybe? | |
| 21:44:21 | mnaser | And so this is why we don’t catch it? | |
| 21:44:30 | NewBruce | mriedem correct / mnaser ill double check | |
| 21:46:08 | NewBruce | quick (not exhaustive) check, upgrade levels is auto | |
| 21:47:48 | NewBruce | we have the same mix of service versions there as well (30 / 35) | |
| 21:49:08 | mnaser | Yet that issue somehow doesn’t happen there | |
| 21:49:14 | mnaser | So off | |
| 21:49:17 | mnaser | Odd | |
| 21:50:21 | mriedem | NewBruce: it fails in _post_live_migration right/ | |
| 21:50:22 | mriedem | ? | |
| 21:51:43 | mnaser | I think so. Rather than deleting the old binding and activating the new one, it tries to update the port binding | |
| 21:51:44 | NewBruce | mriedem correct | |
| 21:51:52 | NewBruce | mnaser correct | |
| 21:52:13 | mnaser | Which is what it would be with old port binding method. | |
| 21:52:49 | mriedem | right in the old method there is just one port binding | |
| 21:52:52 | mriedem | and we change the host on it | |
| 21:55:06 | NewBruce | mriedem and thats the exact behavior we see in RDO - RDO | |
| 21:55:57 | mnaser | So rocky to rocky and it does old port binding | |
| 21:56:32 | mnaser | NewBruce: can you restart a nova-compute with rdo and debug=true and double check the value of upgrade_levels in the output on startup of Oslo CFC | |
| 21:56:37 | mnaser | Cfg | |
| 21:56:43 | mnaser | In case rdo is doing weird stuff | |
| 21:57:14 | NewBruce | sure | |
| 21:57:36 | sean-k-mooney | sound like ye are making some progress on this | |
| 21:57:51 | NewBruce | compute = auto | |
| 21:57:51 | NewBruce | [upgrade_levels] | |
| 21:58:14 | NewBruce | debug=true | |
| 22:00:21 | sean-k-mooney | is the theory that RDO and OSA are not using the same compute RPC version due to there configs eventhough they are running more or less the same code | |
| 22:00:43 | sean-k-mooney | and as a result RDO is useing the old mechaniusm while osa is usign the new mechanisium? | |
| 22:03:10 | NewBruce | mnaser | |
| 22:03:11 | NewBruce | nova-compute.log:2019-04-02 23:59:08.448 10483 DEBUG oslo_service.service [req-4f4874a7-a967-49d1-a643-c59b856c5c61 - - - - -] upgrade_levels.compute = auto log_opt_values /usr/lib/python2.7/site-packages/oslo_config/cfg.py:3032 | |
| 22:03:58 | mnaser | I mean I dug through the conductor code a lot and it checks the source and dest to be above or at a certain later | |
| 22:04:03 | mnaser | Level | |
| 22:04:19 | mnaser | As far as I know the conductor creates the port bindings | |
| 22:04:36 | sean-k-mooney | not in all cases | |
| 22:04:42 | sean-k-mooney | it can be created by the compute node | |
| 22:05:37 | mnaser | Oh really? So I think in the new flow, the new compute node creates it right? | |
| 22:05:38 | mriedem | there is already an active port binding for the source host when you start the live migration, | |
| 22:05:52 | mriedem | in the new flow, conductor will create an inactive port binding for the dest host | |
| 22:06:20 | mriedem | and saves information about that new dest host port binding on the LiveMigrateData.vifs field that gets passed around to the computes | |
| 22:06:25 | sean-k-mooney | https://github.com/openstack/nova/blob/master/nova/conductor/tasks/live_migrate.py#L280-L284 | |
| 22:06:51 | mnaser | Right. That’s what I thought. I even asked NewBruce to set the “dont live migrate until vif is plugged” option that was introduced in rocky as false and moved to true in Stein | |
| 22:06:52 | sean-k-mooney | yes we do the version check the bind the ports on teh destiation | |
| 22:07:11 | mriedem | mnaser: that's unrelated to this | |
| 22:07:30 | mriedem | i mean it was part of the same bp | |
| 22:07:40 | mriedem | but doesn't rely on the active/inactive port bindings | |
| 22:07:46 | sean-k-mooney | mnaser: in the old flow in post livemigate on dest the compute node updated the port binding | |