14:11:16 <PaulMurray> #startmeeting Nova Live Migration
14:11:17 <openstack> Meeting started Tue Apr  5 14:11:16 2016 UTC and is due to finish in 60 minutes.  The chair is PaulMurray. Information about MeetBot at http://wiki.debian.org/MeetBot.
14:11:18 <openstack> Useful Commands: #action #agreed #help #info #idea #link #topic #startvote.
14:11:21 <openstack> The meeting name has been set to 'nova_live_migration'
14:11:28 <PaulMurray> is anyone still here ?
14:11:40 <jlanoux> o/
14:11:50 <davidgiluk> o/
14:11:58 <luis5tb> o/
14:12:34 <PaulMurray> Sorry I was late starting the meeting
14:12:49 <PaulMurray> First time - remarkably
14:12:54 <PaulMurray> agenda here: https://wiki.openstack.org/wiki/Meetings/NovaLiveMigration
14:13:05 <PaulMurray> #topic Bugs
14:13:30 <PaulMurray> nothing in the agenda for bugs, anyone got one to bring up?
14:14:04 <PaulMurray> #topic Specs
14:14:22 <PaulMurray> There is a subteam section
14:14:33 <PaulMurray> in the review pad
14:14:34 <PaulMurray> https://etherpad.openstack.org/p/newton-nova-priorities-tracking
14:14:36 * bauzas lurks at the door
14:15:08 <PaulMurray> We have a request to discuss one today
14:15:11 <PaulMurray> #link Adds post-copy live migration support to Nova: https://review.openstack.org/#/c/301509
14:15:19 <PaulMurray> luis5tb, yours I think
14:15:26 <luis5tb> yep
14:15:42 <luis5tb> I submitted the bp and the spec early today
14:16:43 <PaulMurray> Good, I don't know if anyone has had a chance to look yet ?
14:16:54 <PaulMurray> are there any questions you want to bring up ?
14:17:17 <luis5tb> yep, I would like to know your opinion in a couple of items
14:17:50 <luis5tb> based on the reply I got, seems that it is preferred to make nova automatically choose pre- or post copy as well as the switch between them
14:18:16 <luis5tb> when it is best for the migrations, i.e, when the transfer rate is lower than the amount of memory being dirtied
14:18:59 <davidgiluk> but the challenge is that you can't always use postcopy
14:19:04 <PaulMurray> luis5tb, I think there are two options
14:19:11 <luis5tb> as I'm a new in this, I just wanted to define first the basis, i.e, a way of telling nova to start the migration in post-copy ready mode
14:19:18 <luis5tb> and then when to switch
14:19:20 <PaulMurray> luis5tb, in the last cycle we introduced "force-complete"
14:19:37 <PaulMurray> luis5tb, and it was implemented using pause
14:19:56 <PaulMurray> we expected that other ways to do the completion would come along
14:20:05 <luis5tb> was that triggered by the admin?
14:20:07 <PaulMurray> so this can be an alternative to pause
14:20:19 <PaulMurray> luis5tb, yes
14:20:33 <PaulMurray> luis5tb, the second option would be automatic
14:21:01 <luis5tb> I agree on having a "switch" option similar to force-complete and the automatic one
14:21:04 <PaulMurray> that would be an option for the provider to configure in their config
14:21:11 <luis5tb> just wanted to set first the basis and then go for more advance features
14:21:35 <PaulMurray> I would guess the force-complete would be the place to start
14:21:52 <PaulMurray> and you can come up with ideas on how to decide automatically
14:21:59 <PaulMurray> does that make sense ?
14:22:16 <luis5tb> I agree, to me it seems fairly similar (and I took a look at force-complete specs to write mine)
14:22:56 <luis5tb> that is focusing on the second API (the switch), any input about the first one? extending the nova live-migration command with a post-copy flag?
14:23:59 <luis5tb> In my opinion this should be something to be dynamically chosen by the admin, as you don't want to have all the migrations ready for being switched to post-copy due the the overhead it may suppose
14:24:49 <luis5tb> or do we? in that case, (as D. Berrange suggested) we can avoid any new APIs for post-copy live migration
14:25:21 <PaulMurray> ...just looking at comments
14:26:00 <PaulMurray> I can see dan's point
14:26:15 <PaulMurray> we do avoid anything that is this specific
14:26:39 <PaulMurray> maybe it should just be automatic and an option the provider can configure
14:26:56 <PaulMurray> the admin can always use force-complete to make it happen on demand
14:27:02 <luis5tb> for the switch? or for both APIs?
14:27:29 <PaulMurray> I was thinking that it should be possible as an option on force-complete
14:27:50 <PaulMurray> might need a little discussion on it with people like dan
14:27:51 <luis5tb> yep, maybe we can extend force-complete
14:28:05 <luis5tb> and depend on some configuration, you either do pause or switch
14:28:10 <davidgiluk> PaulMurray: Except it's something that needs enabling at the start of migration (the ability to later switch) and it's only available on some tranports and there are other restrictions; so have to be a little careful
14:28:13 <PaulMurray> force-complete has the same problem that we don't want to be specific about the way its doen
14:28:46 <PaulMurray> davidgiluk, right
14:29:02 <PaulMurray> I the only real issue is how to expose it in the API
14:29:11 <luis5tb> yep, and for the post-copy enable, we need to start the migration with that flag already, as davidgiluk pointed out
14:29:54 <PaulMurray> it has certain properties as a mechanism
14:30:04 <PaulMurray> it can have some overhead on the vm
14:30:10 <PaulMurray> and it is a little more volitile
14:30:21 <PaulMurray> (i.e. a failure after switch is a problem)
14:30:36 <PaulMurray> but its guaranteed to finish
14:31:01 <PaulMurray> so something that uses that as a category rather than saying "post-copy"
14:32:41 <PaulMurray> luis5tb, you could try getting input on ML as not all people with an opinion are in this meeting
14:33:06 <luis5tb> ML?
14:33:13 <PaulMurray> mail list
14:33:17 <PaulMurray> openstack-dev
14:33:59 <luis5tb> ok
14:34:08 <PaulMurray> luis5tb, are you on the mail list ?
14:34:16 <luis5tb> yep, I am
14:34:56 <PaulMurray> We can review you spec and look out for the ML post to get some discussion going
14:35:01 <luis5tb> (that is how I discovered this meetings about live migrations)
14:35:29 <PaulMurray> I dont' think there is much contention except these details
14:35:41 <luis5tb> So, should I write an email with the two side of the coin and see what people think?
14:36:03 <PaulMurray> yes, and give a link to the spec review
14:36:37 <PaulMurray> we can try to settle is quite quickly
14:37:16 <PaulMurray> Anyone one else have a spec to bring up ?
14:38:15 <PaulMurray> #topic Summit sessions
14:38:35 <PaulMurray> regular ref to newton summit ideas: https://etherpad.openstack.org/p/newton-nova-summit-ideas
14:39:09 <PaulMurray> #topic Open Discussion
14:39:14 <PaulMurray> we have something here
14:39:41 <PaulMurray> Use target VIF information on Migration (scheuran)
14:39:49 <PaulMurray> but I don't see scheuran
14:40:44 <PaulMurray> #link Use target VIF information on live migration https://review.openstack.org/#/c/301090/
14:40:50 <PaulMurray> anyone know anything about this ?
14:41:57 <PaulMurray> Something to look at then....
14:42:07 <PaulMurray> Anyone want to bring anything else up ?
14:42:42 <jlanoux> I don't have time to look at it now but it seems there was no progress on CI
14:43:31 <PaulMurray> tdurakov, is there anything planned ?
14:44:00 <tdurakov> hey, sorry missed meeting
14:44:09 <tdurakov> no update for ci now
14:45:07 <PaulMurray> tdurakov, would be good to get a plan together for coming months
14:45:17 <PaulMurray> tdurakov, are you continuing with it ?
14:45:21 <tdurakov> sure
14:45:25 <PaulMurray> tdurakov, do you need help
14:45:39 <tdurakov> nope, will get back for ci next week
14:45:52 <PaulMurray> tdurakov, I'll put it on the agenda :)
14:45:58 <tdurakov> ok
14:46:23 <PaulMurray> I think we are done ?
14:46:57 <PaulMurray> I am very sorry for being late... thanks jlanoux for reminding me
14:47:08 <PaulMurray> thanks for coming
14:47:12 <PaulMurray> #endmeeting