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#openstack-nova - 2017-05-17
18:27:34 cdent or to put it another way: what is the reason for not having simply "more hosts" instead of the nested "alternatives"?
18:27:35 dansmith cdent: each host could satisfy the request.. meaning all the primaries and alternates
18:28:01 dansmith cdent: I had thought about it in terms of just a list of hosts, and not the hierarchy, however:
18:28:28 dansmith cdent: I think the point is that we will, for a single num_instances>1 request, not choose the same primary host for two instances, but the alternates can overlap
18:28:41 dansmith cdent: so the distinction is made such that we consume the primaries
18:29:00 mriedem gyee_: i'm still a bit confused about how this happens if that force flag isn't specified
18:29:12 cdent dansmith: is the additional code complexity worth the win?
18:30:16 dansmith cdent: well, if we don't, then we'll choose hostA, (hostB, C) for the first instance and hostB, (HostA, C) for the second, right? that's a bad decision if we fail on hostB and the first instance filled up hostA
18:30:34 dansmith cdent: also, I think we have to consume the hosts as primaries to keep the existing scheduler behavior, right?
18:31:01 dansmith the previous code did that such that num_instances>1 would not pack them all onto the same host, IIUC
18:31:49 dansmith I dunno, I guess I'd wait for either bauzas or johnthetubaguy to comment on that
18:32:24 cdent thanks dansmith, I'll have to read through it a bit more
18:32:31 cdent it feels like it could be simpler, but feelings may not matter
18:33:16 dansmith well, FWIW, when I first read that code I was kinda horrified with the nested dicting,
18:33:32 dansmith but I didn't complain because I think it probably makes the smallest behavioral change
18:33:52 dansmith it's more code, but I'm not sure it's _that_ much more complex
18:34:20 dansmith it's not an unreasonable opinion though, IMHO
18:34:44 dansmith recording it, even if it is shot down with technical reasons is probably a good idea
18:34:57 cdent roger that
18:35:04 gyee_ mriedem: maybe none != False?
18:35:06 EmilienM mriedem, cdent: super quick fyi: I tested again nova/wsgi and it works fine
18:35:21 cdent yay!
18:35:30 EmilienM this is our config: http://logs.openstack.org/81/462281/3/check/gate-puppet-openstack-integration-4-scenario001-tempest-centos-7/ce2e89d/logs/apache_config/10-nova_api_wsgi.conf.txt.gz
18:35:37 EmilienM if you have any suggestion, feel free to let me know
18:35:47 EmilienM the proof it works http://logs.openstack.org/81/462281/3/check/gate-puppet-openstack-integration-4-scenario001-tempest-centos-7/ce2e89d/logs/apache/nova_api_wsgi_access_ssl.txt.gz
18:36:56 EmilienM mwhahaha: ^ fyi also
18:37:04 mriedem gyee_: i think you might be right https://github.com/openstack/nova/blob/stable/newton/nova/api/openstack/compute/evacuate.py#L92
18:37:13 cdent EmilienM: is cgi-bin/nova/nova-api the new wsgi script that pbr creates?
18:37:26 EmilienM cdent: yes, nova-api-wsgi or something
18:37:35 mriedem gyee_: gah, yeah, that's it
18:37:39 edleafe cdent: my understanding is that if N instances are requested, we'd pick N hosts from the list of weighed hosts. Then for each, we'd get the cell uuid and from the remaining, find enough in the same cell to satisfy the number of alternates needed
18:37:39 EmilienM cdent: /usr/bin/nova-api-wsgi
18:37:49 gyee_ mriedem: two bugs then
18:37:50 mriedem so if you're using microversion<2.29 then force is None
18:37:52 mriedem yup
18:38:01 EmilienM cdent: I need to go now, but you can PM me if you have more comments, i'll catch up later
18:38:03 edleafe So I didn't envision overlap at all
18:38:26 edleafe but I suppose it wouldn't be terrible, since the claim would simply fail on a retry
18:40:09 melwitt dansmith, sdague: I created a WIP devstack patch to add the --tcp option to dstat and added Depends-On it for the caching db connections patch, and compared the output (using active tcp as a hint to db connections)
18:40:30 sdague melwitt: cool, honestly, just add that if you like
18:40:35 melwitt I put them in a spreadsheet here https://docs.google.com/spreadsheets/d/1DIfFfX3kaA_SRoCM-aO7BN4IBEShChXLztOBFeKryt4/edit?usp=sharing
18:40:52 sdague dstat is really there to cross check all these things for runs, so no reason to not report it all the time
18:42:31 melwitt cool. it makes the csv less human readable but I think it's probably worth it for us to be able to have a high level indicator of how many connections we're using http://logs.openstack.org/94/465194/1/check/gate-tempest-dsvm-neutron-full-ubuntu-xenial/7a6b700/logs/dstat-csv_log.txt.gz
18:43:14 dansmith melwitt: not sure I get it.. both tabs top out at ~40 right?
18:43:16 sdague yeh, the non csv version is still emitted as well
18:44:24 dansmith oh
18:44:33 melwitt dansmith: that's listening. I highlighted the "active/established" column, col AC. comparing a gate-tempest-dsvm-neutron-full-ubuntu-xenial in both cases, without caching active connections were 1495 at the end of the run, with caching it was 445
18:44:39 dansmith yeah
18:45:09 dansmith I hadn't scrolled over enough
18:45:28 dansmith well, I guess that's it
18:45:34 dansmith and needing of a backport
18:45:38 dansmith I just dunno why we're never gc'ing those
18:45:41 melwitt ah, I had hoped it would show the scrolling I did to ppl shared with
18:46:06 melwitt yeah, I don't get it either. I thought it should have worked fine the way it was
18:46:30 mriedem melwitt: for your todo in the wip you could use oslo.cache which i think has a default timer
18:46:55 mriedem and can be configured for memcache
18:47:01 dansmith mriedem: will that put it in memcache or dogpile?
18:47:03 dansmith because we probably don't want that
18:47:08 mriedem defaults to dogpile
18:47:09 mriedem in memory
18:47:16 mriedem well, i think
18:47:31 mriedem https://docs.openstack.org/developer/oslo.cache/opts.html
18:47:39 dansmith we just don't want those shared across machines in any way, and not serialized either
18:49:09 melwitt mriedem: I have looked at oslo.cache briefly before and wasn't sure about whether or not to use it. I don't think I found examples in nova
18:49:36 dansmith well, for the backport we can ignore the cache purge,
18:49:45 dansmith since the other lists aren't purged either
18:51:37 melwitt dansmith: I added a thing to clear it upon SIGHUP. as far as expiring based on a timer, the utility of it seems to be mostly around not keeping a connection open to a cell that's seldom used
18:52:23 dansmith right, I'm just saying we needn't worry about any of this for the first patch that we want to be simple for backporting
18:52:34 dansmith I wouldn't even hook up SIGHUP since the other lists are't either
18:53:17 melwitt okay
18:55:01 dansmith related tangent,
18:55:16 dansmith reporting the tcp connection count like this all the time seems like a good thing, and is another thing we could measure and report on independent of worker performance
18:55:29 dansmith i.e "ending tcp connections is >100% higher than expected"
18:55:46 dansmith re: the perf-monitoring forum session
18:55:58 melwitt yeah, I was thinking the same
18:56:30 dansmith I also wonder if we should open a bug against oslo-db for this
18:56:50 melwitt going to un-WIP the devstack patch. sdague, where is the non-csv dstat in the logs? I was wondering should we put --tcp in for both csv and non-csv? I did but I wasn't sure
18:58:26 melwitt dansmith: yeah, should at least ask zzzeek about it and open a bug if it's not an expected thing
19:00:16 sdague melwitt: it's in a screen
19:00:22 sdague well, it's in the journal :)
19:00:26 sdague but we dump it out to screen
19:00:31 sdague files
19:00:34 sdague for compat in gate runs
19:01:35 melwitt cool, thanks
19:06:17 openstackgerrit Artom Lifshitz proposed openstack/nova master: Plumbing for tagged nic attachment https://review.openstack.org/415622
19:06:19 openstackgerrit Artom Lifshitz proposed openstack/nova master: Delete nic metadata when detaching interface https://review.openstack.org/435387
19:06:21 openstackgerrit Artom Lifshitz proposed openstack/nova master: Libvirt support for tagged volume attachment https://review.openstack.org/418100
19:06:25 openstackgerrit Artom Lifshitz proposed openstack/nova master: Delete disk metadata when detaching volume https://review.openstack.org/435082
19:06:33 openstackgerrit Artom Lifshitz proposed openstack/nova master: Plumbing for tagged volume attachment https://review.openstack.org/391941
19:06:34 openstackgerrit Artom Lifshitz proposed openstack/nova master: API support for tagged device attachment https://review.openstack.org/376021
19:06:36 openstackgerrit Artom Lifshitz proposed openstack/nova master: Libvirt support for tagged nic attachment https://review.openstack.org/415520
19:10:56 openstackgerrit Steve Noyes proposed openstack/nova master: WIP: update live migration to use v3 cinder api https://review.openstack.org/463987
19:11:46 melwitt sdague: patch has been un-WIP https://review.openstack.org/#/c/465194
19:12:03 sdague melwitt: +2, thanks
19:12:33 melwitt thx
19:16:21 cdent dansmith, bauzas, edleafe I tried to leave some questions on https://review.openstack.org/#/c/465175/ to capture my concerns, but not sure if they are clear
19:17:56 openstackgerrit Matt Riedemann proposed openstack/nova master: Destroy the ReqSpec object when deleting the instance https://review.openstack.org/391060
19:40:09 openstackgerrit Matt Riedemann proposed openstack/nova master: Plumbing for tagged nic attachment https://review.openstack.org/415622
19:40:11 openstackgerrit Matt Riedemann proposed openstack/nova master: Delete nic metadata when detaching interface https://review.openstack.org/435387
19:40:13 openstackgerrit Matt Riedemann proposed openstack/nova master: Libvirt support for tagged volume attachment https://review.openstack.org/418100

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