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#openstack-nova - 2017-04-26
21:18:11 mriedem i think liberty?
21:18:13 mriedem for reqspec
21:18:21 dansmith yeah, he was asking about increased connections for api/nova db right?
21:18:24 cfriesen mriedem: no, our clouds are small enough we don't use cells. but we did see nova basically doubling the number of DB connections going from Mitaka to Newton.
21:19:45 mriedem actually i guess reqspec was mitaka https://review.openstack.org/#/c/211753/
21:20:20 mriedem so what's hitting the api db in newton? build request right?
21:20:39 cfriesen mriedem: yeah, I see the api db in mitaka
21:21:04 clarkb dansmith: we cache the list results for that reason
21:21:09 mriedem in newton i suppose we are using build request and looking up instance, host and cellmappings even if we're just getting NotFounds
21:21:15 dansmith clarkb: yeah, it's sad
21:21:17 clarkb (as well as caching everyting else)
21:21:31 cfriesen mriedem: aggregates maybe?
21:21:39 dansmith cfriesen: no
21:21:47 mriedem flavors are in the api db
21:22:35 mriedem and keypairs, and aggregates, and server groups
21:22:57 mriedem and those are doing online data migrations
21:23:28 cfriesen we use aggregates and flavor extra specs a lot
21:23:37 mriedem so we might have some overhead for checking for online data migrations which are not necessary once you've migrated everything
21:24:00 melwitt for any target_cell, a new oslo.db _TransactionContextManager will be created to make the connection
21:24:09 clarkb dansmith: that said we peaked booting at 30k instances a day across multiple clouds/regions so 10s isn't the end of the world
21:24:22 clarkb dansmith: and I'm guessing more users do far less so its not a major headache
21:24:42 dansmith clarkb: well, it still sucks, don't try to convince me :)
21:24:54 clarkb oh I agree, just trying to point out why people probably don'
21:24:56 clarkb t scream at you
21:24:57 melwitt dansmith: is the 10s sans novaclient or is it novaclient?
21:25:44 mriedem yeah doesn't novaclient look up the image for every instance to show the image name in the output?
21:26:16 mriedem cfriesen: https://github.com/openstack/nova/blob/master/nova/cmd/manage.py#L602
21:26:29 mriedem should give you an idea of online data migrations added in newton
21:26:55 mriedem which is a lot
21:26:56 cfriesen mriedem: thanks. so basically most nova services would be expected to have connections open to both DBs now?
21:27:08 mriedem cfriesen: only nova-api, conductor and scheduler
21:27:34 cfriesen right, the heavyduty ones other than nova-compute
21:28:02 mriedem cfriesen: have you guys done any profiling of where the worst hits are?
21:28:28 cfriesen not yet...someone was just complaining about maybe needing to bump up the limit on overall DB connections.
21:28:29 mriedem dansmith: we should maybe look at blocker migrations for pike so we can stop dropping these older online data migration routines
21:28:42 mriedem s/stop/start/
21:28:43 mriedem :)
21:28:49 dansmith hah, was confused
21:29:13 dansmith sure, but they're not that expensive so I've been working on other stuff
21:30:41 mriedem wonder if any of the versioned notification stuff is blowing up perf by doing lazy-loads
21:33:19 mriedem yeah i guess with like the online flavor migrations, those are all of the style where we looking in the api db first, then fallback to looking in the main cell db
21:33:29 mriedem we don't migrate those in the object code, we leave that for the online_data_migrations CLI
21:33:44 mriedem cfriesen: have you guys been running the online_data_migrations CLIs in newton?
21:36:23 mriedem dansmith: so say i wanted to remove all of the api->cell_db checking code in the flavor object during the lookup methods, are the steps add a blocker db migration, then drop the compat code in the flavor object, but leave https://github.com/openstack/nova/blob/master/nova/cmd/manage.py#L604 since you need that to get through the blocker migration
21:36:47 mriedem this doesn't buy us anything for perf, but it would drop all of that compat code in the flavor object
21:37:20 dansmith mriedem: historically we've done the blocker and then removed it, saying you had to use N-1 code to do the migration
21:37:25 dansmith but those were thigns we really wanted to drop
21:37:32 dansmith and it was all intertwined with object code
21:37:41 dansmith and, we always do blockers as the first migration
21:37:46 mriedem yeah i figured we wouldn't have to here b/c the object code isn't doing a migration
21:37:54 dansmith potentially
21:38:24 mriedem before you start using multiple cells you should really have your flavors in the api db
21:38:29 dansmith yes :)
21:38:36 mriedem in fact....
21:38:55 mriedem multi-cell basically breaks the lookup routine since we don't know which cell db to fallback to if the flavor isn't in the api db
21:39:14 mriedem so we kind of need to drop all of that code anyway i'd think
21:39:44 dansmith I'm confinced
21:39:47 dansmith convinced even
21:40:24 mriedem are we unable to do this if the blocker migration isn't the first migration for pike?
21:40:44 dansmith no, we did that to avoid you being able to keep running on N-1 code
21:40:54 dansmith like, we tweak your db, then tell you you can't run N without migrating in N-1,
21:40:59 dansmith but N-1 might choke on the tweaks
21:41:01 dansmith that would be evil
21:41:15 dansmith if you're not dropping the migration code, then I guess you could do it
21:41:33 mriedem right that's why i said we still keep https://github.com/openstack/nova/blob/master/nova/cmd/manage.py#L604
21:42:07 mriedem but you really need to purge this stuff out of your main cell db and get it into api before you can do multiple cells
21:42:20 mriedem maybe a nice reminder for your summit talk :)
21:44:28 dansmith heh
21:45:17 mriedem so https://review.openstack.org/#/c/374307/
21:45:23 mriedem we already enforced this in ocata :)
21:46:26 dansmith flavors yeah
21:46:36 mriedem and keypairs, aggregates and server groups
21:46:44 dansmith and those yeah
21:48:44 openstackgerrit Dan Smith proposed openstack/nova master: WIP: De-complicate some of the instance delete path https://review.openstack.org/458636
21:48:44 openstackgerrit Dan Smith proposed openstack/nova master: Move to proper target_cell calling convention https://review.openstack.org/458634
21:48:45 openstackgerrit Dan Smith proposed openstack/nova master: Make target_cell() yield a new context https://review.openstack.org/458635
21:48:45 openstackgerrit Dan Smith proposed openstack/nova master: DNM: Canary test against multi-cell devstack https://review.openstack.org/458537
22:09:11 efried mordred Still around?
23:05:39 mordred efried: hey! not really - EODing - catch you in the morning?
#openstack-nova - 2017-04-27
00:39:48 mriedem dansmith: i just got thinking that maybe we shouldn't have removed the online data migration hook in https://review.openstack.org/#/c/448579/ but then again that was added in mitaka, and the blocker migration was added in newton. the thing that makes me 2nd guess it is people skipping releases for upgrades.
00:39:54 mriedem which we don't support, but people do it
00:40:02 mriedem skipping from newton to pike though, would be nuts
00:41:14 mriedem the online flavor migration was added in newton, the blocker migration was added in ocata, so theoretically we could remove all of that in pike, but if people skip ocata, and we removed the online data migration CLI for flavors, they'd be screwed
00:47:13 mordred mriedem: skip-upgrades seem like a completely crazy thing if they're not actually supported and planned for
00:48:57 efried mordred Yes, mañana. Want to make sure I'm on the right track with https://review.openstack.org/#/c/460337/ and ask some questions about same.
00:49:39 mordred cool- looking forward to it
00:51:02 mordred efried: oh great - I missed that you'd pushed that up - I'll read it first thing
00:58:11 mriedem mordred: yeah, except ops are always talking about doing it
00:58:18 mriedem because we don't have LTS or whatever
01:16:55 mriedem dansmith: oh fun, uncovered a bug removing all of this flavor object compat code for the main cell db,
01:17:13 mriedem when sending a flavor delete notification, we lazy-load the projects which results in a FlavorNotFound b/c we just deleted that flavor
01:23:42 mriedem looks like that's due to https://review.openstack.org/#/c/445697/
02:53:33 openstackgerrit Matt Riedemann proposed openstack/nova master: WIP: Remove compatibility code for flavors https://review.openstack.org/460377
02:55:46 morgan huh I saw my name here
02:55:51 morgan what did I miss?
02:56:00 morgan can't find it in the backlog ATM.
03:48:31 RiteshPaiboina who jaypipes
04:18:02 openstackgerrit falseuser proposed openstack/nova master: [BugFix] Check the instance task status to release the memory quota for vram https://review.openstack.org/456050
04:18:03 openstackgerrit falseuser proposed openstack/nova master: [BugFix]Include the video ram when comparing the difference of two flavors https://review.openstack.org/460388
05:15:37 openstackgerrit Kiseok Kim proposed openstack/nova master: Fixed a broken link in API Plugins document https://review.openstack.org/460398

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