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#openstack-nova - 2017-08-09
17:44:42 mnaser i dont even see it in the siblings there, i wonder if it is in the process of the transformation to the DB object
17:47:15 cfriesen mriedem: what do you think of this wording? http://paste.openstack.org/show/617966/
17:48:40 mriedem "If you have ``scheduler_driver`` set to ``caching_scheduler``, you should probably add these entries back in along with CoreFilter."
17:48:51 mriedem issue the first: scheduler_driver is the old option name
17:48:57 mriedem it's now [scheduler]/driver
17:49:14 cfriesen whoops, was looking at wrong window. :)
17:49:42 mriedem issue the 2nd: let's not tell them what to do if they're not using the filter scheduler, but just point out that non-FilterScheduler drivers, like the CachingScheduler, may want to have these filters enabled
17:49:49 cfriesen okay
17:50:09 mriedem if they already have that option defined in their nova.conf, then they don't have to 'add' anything back in, as it's already there, and we're just changing the defaults
17:50:26 cfriesen mriedem: the issue I'm worried about is if they were relying on the defaults
17:50:48 mriedem sure, and that's why you point out that non-FilterScheduler drivers, like the CachingScheduler, may want to have these enabled
17:50:58 cfriesen fair enough
17:52:16 mriedem isn't there also a case that you don't want the DiskFilter enabled - if you're using shared storage?
17:52:29 mriedem looks like we never documented that in the description for the DiskFilter
17:53:07 mriedem i'm not saying you need to for this change, but just thinking of the operator that then starts looking at if they need to enable these or not - will they have enough information to make that decision
17:53:49 cdent thanks mriedem, by being assigned the fix for that bug, I should receive a gloriously huge bug bounty from … someone
17:54:02 mriedem tjones
17:54:11 mriedem has the bug bounty kitty
17:54:27 openstackgerrit Dan Smith proposed openstack/nova master: Mark Chance and Caching schedulers as deprecated https://review.openstack.org/492210
17:54:31 dansmith mriedem: ^
17:57:07 openstackgerrit Chris Friesen proposed openstack/nova master: Remove ram/disk sched filters from default list https://review.openstack.org/491854
17:57:28 mriedem dansmith: lgtm
17:57:48 mnaser cfriesen my apologies, looks like wrong config.. but i think i've narrowed it down to this: AVAILABLE_SIBLINGS: [CoercedSet([8, 24]), CoercedSet([2, 18]), CoercedSet([10, 26]), CoercedSet([28, 12]), CoercedSet([22, 6]), CoercedSet([30, 14]), CoercedSet([20, 4])] .. technically there should be more set in there with CoercedSet([16]) -- because the 0 is reserved
17:58:01 mnaser it's removed the entire set rather than the single one
17:58:09 cfriesen dansmith: is the performance of FilterScheduler with Placement comparable to CachingScheduler?
17:58:12 mnaser (this might be obvious to you but i'm just figuring it out, heh)
17:58:58 dansmith cfriesen: it should end up being much better
17:59:24 cfriesen mnaser: if you've got 0/1 reserved then I think arguably there should be a set with just 16 and another set with just 17
18:00:03 cfriesen it should be noted though that the performance of 16/17 is going to be variable, depending on what load is on 0/1
18:00:40 cfriesen dansmith: better? isn't CachingScheduler in memory for the most part?
18:00:42 mnaser of course, that's a given
18:01:38 dansmith cfriesen: we've been discussing this in this channel for like I year, so I hope I don't have to summarize all of it, but if you count the ability to multi-thread the scheduler with placement, and zero reschedules, yes, it should be much better
18:01:54 dansmith s/I/a
18:02:02 mriedem roman numeral I
18:02:05 mriedem you meant
18:02:11 sdague dansmith: I did not push the deprecation of the other schedulers
18:02:11 dansmith heh, yeah
18:02:17 sdague dansmith: if that's a patch that is needed, I could do it this afternoon
18:02:18 dansmith sdague: I just did
18:02:23 mriedem https://review.openstack.org/#/c/492210/1
18:02:25 sdague dansmith: ok, coolio
18:02:35 cfriesen dansmith: ah, you mean overall scheduler load. got it. (I was thinking time to perform a single schedule operation.)
18:02:42 mnaser https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L5632-L5633 -- bingo.. now to see why the decision of filtering out singles is there
18:02:51 mriedem cfriesen: it's also that
18:03:00 mriedem time to schedule should be faster when you don't have reschedules
18:03:02 mriedem b/c of bad decisions
18:03:41 mriedem cfriesen: your team seems to do some performance testing, it would be cool if your guy(s) could benchmark and compare the two now in pike
18:04:00 dansmith if you really care about the milliseconds requried to place something, you should be able to do better with a bunch of filterschedulers than one in-memory caching scheduler I would think
18:04:00 mriedem like single caching scheduler vs multiple filter schedulers
18:04:08 cdent cfriesen: it may be the case, but I’m not sure that anyone has proven it yet, that single schedule operations will speed up because placement will help limit the initial set of available candidates
18:04:51 dansmith cdent: cachingscheduler only refreshes the list when it runs out of spots I think, so it varies, but it also is using very outdated information which means fast but poor decisions
18:05:09 cfriesen I'd expect the FilterScheduler to speed up due to Placement. Wasn't sure that it'd be faster than CachingScheduler. Anyways, we've been using FilterScheduler since we care about accurate resource tracking.
18:05:16 mriedem caching scheduler is also on a periodic
18:05:45 cfriesen (We modified stuff like resize and migration to update the resource tracking immediately rather than wait for the resource audit.)
18:05:49 dansmith caching scheduler is filter scheduler, with cached host list data
18:06:18 mriedem dansmith: so this resize/rt series has a pep8 failure in the bottom change,
18:06:31 mriedem dansmith: but i guess hold off on fixing that so i can go through them now
18:06:33 mriedem the last 2 i mean
18:06:41 dansmith okay
18:06:46 mriedem dansmith: it's T-~3 hours to 0 dan time yeah?
18:06:53 dansmith check queue is 7h long
18:07:26 dansmith mriedem: I think you mean T-3 hours until free-of-dan time
18:07:27 dansmith but yeah
18:07:55 dansmith I assume everyone brought liquor and cake to work today for the post-2pm PDT party
18:08:14 mriedem brought? i think it's just generally available
18:08:47 dansmith I was trying to act like it was the 90s
18:13:40 mnaser cfriesen thanks for all your feedback, i think the best solution for now is going to be use 0,16 to have predictable performance for the host and assign hugepages with a slight bias towards node1 because it has 2 more cores so things can get properly packed
18:23:37 sdague dansmith: yeh, we're down to 800 nodes in ci
18:23:54 sdague which is unfortunately not sufficient
18:24:16 dansmith well, it was fun while it lasted
18:25:50 sdague if anyone wants to do doc reviews to hopefully complete the import - https://review.openstack.org/#/q/status:open+project:openstack/nova+branch:master+topic:bp/doc-migration
18:30:06 cfriesen mnaser: sorry you hit a bug. :) we should be able to get it sorted out once sfinucan comes back from holidays
18:31:07 cfriesen mnaser: ping me with the bug number once you file it please
18:41:12 mriedem dansmith: jaypipes: cdent: edleafe: problems https://review.openstack.org/#/c/488510/
18:42:23 dansmith mriedem: I +2d before we had jenkins runs of the latest version
18:42:27 dansmith and it was passing (tempest) before
18:42:35 mriedem it's not that it's not passing tempest
18:42:41 mriedem it's just spewing ERRORs
18:42:46 jaypipes hey guys, just got back.
18:43:33 jaypipes hmm, yes, the dreaded ./nova/compute/resource_tracker.py:1112:17: N352 LOG.warn is deprecated, please use LOG.warning!
18:44:12 mriedem heh i even pointed that out
18:44:17 mriedem it's in the bottom change btw
18:44:23 mriedem so the entire series needs to be rebaesd
18:44:24 mriedem *rebased
18:44:32 mriedem but i have issues with the 2nd change in the series
18:45:02 jaypipes yeah, I see that
18:45:14 dansmith mriedem: we have the placement upgrade before nova thing required in the prelude of the renos
18:45:21 dansmith which should be enough to merge this, IMHO
18:45:44 jaypipes "prelude of the renos" sounds like some classical music composition.
18:46:25 mriedem dansmith: where?
18:46:26 dansmith I probably shouldn't be reviewing this anyway since I was elbow deep in it myself
18:46:28 mriedem i know it's in the release notes
18:46:35 mriedem but it's not in the prelude
18:46:53 mriedem https://docs.openstack.org/releasenotes/nova/unreleased.html#id1
18:46:58 mriedem A new 1.10 API microversion is added to the Placement REST API. This microversion adds support for the GET /allocation_candidates resource endpoint. This endpoint returns information about possible allocation requests that callers can make which meet a set of resource constraints supplied as query string parameters. Also returned is some inventory and capacity information for the resource providers involved in the allocation
18:46:58 mriedem idates.
18:47:19 mriedem wrong one
18:47:19 mriedem https://docs.openstack.org/releasenotes/nova/unreleased.html#upgrade-notes
18:47:25 mriedem The scheduler now requests allocation candidates from the Placement service during scheduling. The allocation candidates information was introduced in the Placement API 1.10 microversion, so you should upgrade the placement service before the Nova scheduler service so that the scheduler can take advantage of the allocation candidate information.
18:47:42 mriedem the code totally falls back though if 1.10 isn't available

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