| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2017-03-16 | |||
| 15:28:28 | mriedem | there doesn't seem to be much they're not willing to do in their company | |
| 15:28:29 | mdbooth | Not during rollback_at_destination | |
| 15:28:31 | mriedem | mdbooth: ^ | |
| 15:28:48 | mdbooth | mriedem: Hehe. | |
| 15:30:42 | mdbooth | lyarwood: Sorry, yes. instance.host *will* be the source. I didn't read you right there. | |
| 15:30:56 | mdbooth | However, it's executing on the destination, which is the problem. | |
| 15:31:11 | mdbooth | self.compute_rpcapi.remove_volume_connection( | |
| 15:31:11 | mdbooth | context, instance, bdm.volume_id, dest) | |
| 15:31:20 | mdbooth | In _rollback_live_migration | |
| 15:31:25 | lyarwood | mdbooth: haha right, I just couldn't find the instance.host update | |
| 15:31:43 | mdbooth | So CONF.host != instance.host | |
| 15:31:52 | mdbooth | BUT, we still need to tear it down | |
| 15:32:07 | mdbooth | So I feel like that's the sort of logic that lives in ComputeManager | |
| 15:32:12 | lyarwood | well, we are going to call destroy that's going to do that anyway | |
| 15:32:37 | lyarwood | but sure, I get your point | |
| 15:33:53 | lyarwood | mriedem / johnthetubaguy ; if you have anytime before the cinder meeting the uuid and attachment_id change could really use core review - https://review.openstack.org/#/q/topic:bp/cinder-new-attach-apis & https://review.openstack.org/#/q/status:open+project:openstack/nova+branch:master+topic:bug/1489581 | |
| 15:34:01 | mriedem | dansmith: sdague: melwitt: can we get https://review.openstack.org/#/c/444106/ and the test patch below it in so we can move forward with the backport? it would also help ironic ci that is failing on this. | |
| 15:34:02 | bauzas | dansmith: have you seen my comment on archive_deleted_rows ? | |
| 15:34:18 | mriedem | lyarwood: ok, i meant to go through those again today | |
| 15:34:23 | dansmith | bauzas: you said you didn't think you could use it, but didn't say why (or that I saw) | |
| 15:34:39 | bauzas | dansmith: because the logic in there is looping over the cell DB tables | |
| 15:34:46 | dansmith | bauzas: obviously some refactoring will be needed, but I just would like to avoid having to add yet another command to run cleanup | |
| 15:34:56 | dansmith | mriedem: yeah | |
| 15:34:57 | bauzas | to push them in their shadow one | |
| 15:35:23 | mdbooth | lyarwood: In case you didn't notice, I thought the problem in _from_db_object() here was pretty severe: https://review.openstack.org/#/c/242603/23/nova/objects/block_device.py | |
| 15:35:30 | bauzas | dansmith: the main point is that we provide the number of rows per table archived | |
| 15:36:01 | dansmith | bauzas: not per table, but that applies to the thing we need to do in reqspec too right? | |
| 15:36:12 | bauzas | dansmith: so I should say how many rows for the request_spec table are 'archived', ie. killed? | |
| 15:36:25 | bauzas | dansmith: nope, this is per table AFAICS | |
| 15:36:37 | bauzas | you return either 0 or 1 | |
| 15:36:38 | openstackgerrit | Moshe Levi proposed openstack/os-vif master: HW offload support for openvswitch https://review.openstack.org/398277 | |
| 15:36:38 | dansmith | bauzas: in fact, you have to look at the cell dbs to know what you can remove from reqspec, right? | |
| 15:36:39 | sdague | mriedem: ... once I finish updating the limits spec | |
| 15:36:46 | openstackgerrit | Matt Riedemann proposed openstack/nova master: libvirt: add debug logging in detach_device_with_retry https://review.openstack.org/446601 | |
| 15:36:47 | mriedem | lyarwood: ^ is the debug patch for detach | |
| 15:37:00 | bauzas | but the verbose prints that | |
| 15:37:11 | dansmith | bauzas: are you talking about the parameter or what gets printed? | |
| 15:37:16 | bauzas | dansmith: what's printed | |
| 15:37:24 | lyarwood | mdbooth: yeah sorry I did miss that, are you sure that doesn't result in a save straight away? | |
| 15:37:38 | bauzas | dansmith: for looking at which record to remove, I was rather thinking on looking at InstanceMapping | |
| 15:37:39 | mdbooth | lyarwood: If it does, I don't know how | |
| 15:37:46 | bauzas | oh wait | |
| 15:37:54 | dansmith | bauzas: you need to purge those too | |
| 15:37:57 | bauzas | dansmith: we don't remove yet also InstanceMapping records? | |
| 15:38:02 | bauzas | a-ha, yeah | |
| 15:38:13 | dansmith | we don't in the case of soft delete, but otherwise we do | |
| 15:38:19 | bauzas | erf | |
| 15:38:30 | bauzas | okay, then I need to look at all the cells, yeah | |
| 15:38:50 | bauzas | I should also purging the instance_mappings too then | |
| 15:38:56 | lyarwood | mdbooth: ah I might be mixing this up with the driver_bdm dict updates that result in a save | |
| 15:39:04 | bauzas | well, okay, I'll see what I can do to use the same command | |
| 15:40:12 | mdbooth | lyarwood: Also, in the previous patch I didn't like the unnecessary argument type ambiguity. But I think I was ok with everything else. | |
| 15:44:04 | lyarwood | mdbooth: the uuid vs bdm_uuid issue? | |
| 15:44:12 | mdbooth | lyarwood: No, just a sec | |
| 15:44:40 | lyarwood | mdbooth: ah the cellv1 values thing | |
| 15:44:54 | mdbooth | https://review.openstack.org/#/c/242602/22/nova/db/sqlalchemy/api.py | |
| 15:45:03 | mdbooth | block_device_mapping_update | |
| 15:45:47 | mdbooth | The caller has full context, and there are multiple ways to pass it in unambiguously | |
| 15:46:32 | lyarwood | mdbooth: right and at the moment that's always the id so we can just drop this for now | |
| 15:47:05 | mdbooth | Well then you'd have to drop the change in update_or_create | |
| 15:47:52 | mdbooth | It shouldn't be a complex fix. | |
| 15:48:09 | lyarwood | ah yeah got it | |
| 15:48:30 | dansmith | bauzas: remind me, we don't delete reqspec at all right now, but will in the case of non-soft delete soon right? | |
| 15:48:47 | dansmith | bauzas: so this command will really only be needed if operators have soft delete enabled, right? | |
| 15:49:02 | bauzas | dansmith: yup, we don't delete the spec yety | |
| 15:49:45 | bauzas | dansmith: if someone hard-deletes an instance (ie. the instance now longer exists), then we should purge the entry | |
| 15:49:52 | mriedem | mdbooth: lyarwood: in case you haven't noticed yet, the original patches to add bdm.uuid were for a cellsv1 race issue where update_or_create happened at the api cell and things got racey and crazy, | |
| 15:50:05 | mriedem | mdbooth: lyarwood: so that's why there is the update_or_create stuff | |
| 15:50:08 | dansmith | bauzas: you're saying you will soon delete reqspec at normal instance delete time, yes? | |
| 15:50:09 | bauzas | dansmith: tbc, I was planning to iterate over all the spec records, and lookup over all cells to see if some instance exists | |
| 15:50:18 | bauzas | for the purge command | |
| 15:50:31 | dansmith | not talking about purge, I'm talking about normal api delete.. | |
| 15:50:35 | mriedem | mdbooth: lyarwood: but i believe that update_or_create is also still called from the compute api (and/or conductor now) when creating the bdms | |
| 15:50:49 | bauzas | dansmith: ah, that, I wasn't planning to introduce it given mriedem's point | |
| 15:50:59 | dansmith | bauzas: his point about what? | |
| 15:51:16 | bauzas | dansmith: the fact that we shouldn't delete the spec record in case this is an instance soft-delete | |
| 15:51:19 | mdbooth | mriedem: IIRC that's correct. The cellsv1 caller was unique in that it passed in a versioned object instead of a list of update values, though. | |
| 15:51:27 | bauzas | dansmith: https://review.openstack.org/#/c/391060/2/nova/compute/api.py@1804 | |
| 15:51:54 | dansmith | bauzas: right but assuming like 1% of people use soft delete, we should do the right thing in the 99% case and only require people that use soft-delete to have to worry about this purge | |
| 15:52:01 | dansmith | I dunno what percentage do use it, but we should always delete if we know we can | |
| 15:52:16 | bauzas | dansmith: so, I could just verify if it's a soft-delete ? | |
| 15:52:42 | bauzas | dansmith: and if it's not a soft-delete, then call the _delete_req_spec method? | |
| 15:52:57 | dansmith | bauzas: yeah, of course, I'm not sure why we wouldn't | |
| 15:53:00 | bauzas | lemme verify, but delete_type seems the good argument for verify it | |
| 15:53:37 | bauzas | dansmith: honestly, purging using the archive command would be super-expensive | |
| 15:54:02 | bauzas | because I need to iterate over all the spec records, and then iterate over all cells for each record, so o(n2) | |
| 15:54:03 | dansmith | bauzas: further, in the purge command, it's going to be very intensive to compare all the current reqspecs with all the deleted=1 instances in a cell, so I think you should just do the api-db purge when you archive an instance row, which will be much more efficient. | |
| 15:54:09 | dansmith | bauzas: yeah, that's completely not okay | |
| 15:54:34 | dansmith | bauzas: doing the purge inside archive_deleted_rows is the only place you can do it efficiently | |
| 15:54:47 | dansmith | a separate purge command will have to do it O(n^2) | |
| 15:55:08 | bauzas | yeah, sorry my keybord doesn't ² :p | |
| 15:55:19 | dansmith | a separate purge command will not be able to effectively determine which deleted instances already have a purged api-db record, | |
| 15:55:21 | dansmith | which makes it expensive | |
| 15:55:26 | dansmith | and after you archive, it's too late | |
| 15:55:37 | bauzas | dansmith: correct me if I'm wrong, but archive_deleted_rows isn't yet cells-aware ? | |
| 15:55:40 | dansmith | but if you do it when you archive, then you can do it in O(n) just like archive is now | |
| 15:56:03 | mdbooth | lyarwood: On locking, I think that everything in api which checks instance/task state should be required to immediately and atomically modify task state. That's probably the level of locking required for rebuild. | |
| 15:56:07 | dansmith | bauzas: what does it matter if it is? whether you're doing one cell db or all of them, it's the same amount of work | |
| 15:56:07 | mriedem | bauzas: the delete_type arg is what tells you the type, | |
| 15:56:15 | mriedem | "soft_delete" or just "delete" | |