| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2017-09-27 | |||
| 13:33:58 | bauzas | we shouldn't really create a way where people would directly call their VMs if they wish, because that would mean we would silently say we support that | |
| 13:34:20 | efried | Cause the alternative is maintaining some kind of cache and trying to keep it up to date every time a VM gets spawned or deleted (I can get notifications for the OOB ones, and update the in-band ones from spawn/destroy). | |
| 13:34:38 | bhagyashris | johnthetubaguy: Actually I have not respond yet, but Andrey Volkov is given -1 and he suggested that we can fix this issue at schema level (same thing I have proposed in the patch set 3) but after some discussion we decided to fix this in logic and at schema level. | |
| 13:34:44 | bauzas | if the operator doesn't know the dedicated amount their wanna reserve, then either they should disable some compute from the pool, or just set a high value | |
| 13:35:18 | johnthetubaguy | but isn't the easy case much easier here? deployer sets the reserved values, no period updates, worry about special cases later? | |
| 13:35:19 | bauzas | providing a way to dynamically adjust resources in Nova would just mean we create things to support | |
| 13:35:23 | cdent | johnthetubaguy, bauzas: perhaps sad, but true, there are in tree hypervisors where oob vms are fairly common. nova in itself may not need to support that, but the hypervisors will likely continue doing it | |
| 13:35:25 | bhagyashris | s/and at schema level/and not at schema level | |
| 13:35:50 | bauzas | johnthetubaguy: that's my point | |
| 13:36:08 | dansmith | mriedem: have you seen the stuff I added to the etherpad last night? | |
| 13:36:22 | bauzas | johnthetubaguy: if operators really want a space for out-of-band VMs, then they have the reserved bit they can set and try to modify when they feel necessary | |
| 13:36:43 | bhagyashris | johnthetubaguy: i will respond to that question. | |
| 13:36:54 | johnthetubaguy | cdent: but even those drivers, there are folks who run dedicated clusters just for OpenStack | |
| 13:36:54 | bauzas | but trying to provide some mechanism for having a dynamic reserved bit seems to me something we shouldn't do | |
| 13:37:41 | bauzas | and honestly, wouldn't it be better to just disable a host and play with it, if that's really needed ? | |
| 13:37:44 | cdent | johnthetubaguy: yes, totally | |
| 13:37:47 | johnthetubaguy | cdent: that was me arguing for making the sync optional, for when you know Nova owns the world | |
| 13:37:58 | rgerganov | johnthetubaguy, most users runs dedicated clusters but also used shared storage | |
| 13:38:07 | dansmith | johnthetubaguy: are you talking about the periodic that will try to delete unknown vms? | |
| 13:38:09 | mriedem | dansmith: sure did | |
| 13:38:14 | johnthetubaguy | bhagyashris: thanks, responding in the review will help wehn I get back to that | |
| 13:38:21 | mriedem | dansmith: nope, talking about update_available_resource | |
| 13:38:41 | mriedem | and using get_inventory to report reserved space for other things running on the hypervisor outside of nova's control | |
| 13:38:41 | johnthetubaguy | dansmith: well, I was thinking about that early, with all the logging by default, but there I was meaning the resource tracker updater | |
| 13:39:10 | dansmith | mriedem: eff that. there's a reserved count for that kind of stuff. | |
| 13:39:17 | bhagyashris | johnthetubaguy: Thank you :) | |
| 13:39:34 | mriedem | dansmith: meaning the config option? | |
| 13:39:48 | dansmith | meaning counting other things and subtracting it ourselves | |
| 13:40:02 | mriedem | i think the config option is what's used to report reserved inventory in the RT today | |
| 13:40:13 | dansmith | yes | |
| 13:40:33 | dansmith | well, actually, I dunno that it is today, but it should be, and that should be your outlet to carve out space | |
| 13:41:12 | dansmith | it is | |
| 13:41:17 | dansmith | https://github.com/openstack/nova/blob/master/nova/compute/resource_tracker.py#L102-L125 | |
| 13:41:39 | dansmith | make those hot-reloadable if you want, but that's the path, IMHO | |
| 13:42:58 | efried | dansmith That guy still gets run on a periodic basis, right? I.e. dynamic tweaking of reserved amounts is supported (at least by the driver - not asking if those conf opts are dynamic) | |
| 13:43:31 | johnthetubaguy | we should make SIG_HUP trigger a resource refresh? | |
| 13:43:46 | dansmith | johnthetubaguy: HUP already triggers a config re-read | |
| 13:43:54 | johnthetubaguy | I was meaning a resource tracker update | |
| 13:44:03 | dansmith | johnthetubaguy: so if they were reloadable you'd get a new value the next time inventory runs | |
| 13:44:07 | johnthetubaguy | so we don't have to keep the periodic thing, just do it on events | |
| 13:44:30 | dansmith | I'm not sure there's any reason not to do it perioically | |
| 13:44:53 | johnthetubaguy | system load, all that lists of instances, etc | |
| 13:45:28 | dansmith | it doesn't need to anymore | |
| 13:46:00 | dansmith | in pike, once there aren't any ocata computes around we're not doing healing for instances other than deleted ones | |
| 13:46:31 | johnthetubaguy | I guess I am confused | |
| 13:47:24 | johnthetubaguy | I thought we were left with no periodic updates in queens | |
| 13:47:31 | johnthetubaguy | to inventory, etc | |
| 13:47:44 | johnthetubaguy | although... ironic needs those | |
| 13:47:52 | johnthetubaguy | dang it | |
| 13:48:19 | dansmith | I'm saying, we can remove a bunch of the RT stuff for healing instances now I think, | |
| 13:48:34 | johnthetubaguy | ah, OK, so maybe I am agreeing with you | |
| 13:48:35 | dansmith | which will make the periodic mostly an inventory mechanism, which doesn't need to be listing instances and such | |
| 13:49:32 | efried | The periodic will use driver.get_inventory() to update inventories? | |
| 13:49:57 | efried | (still) | |
| 13:50:04 | dansmith | or get_available_resource() if it doesn't have that | |
| 13:50:09 | efried | Cool. | |
| 13:50:10 | dansmith | or whatever that method is called | |
| 13:50:49 | efried | So I think the point is that, in order to do dynamic adjustment of 'reserved' amounts properly, get_inventory itself may need to be listing instances and such. | |
| 13:50:59 | dansmith | no | |
| 13:51:07 | dansmith | inventory has nothing to do with instances | |
| 13:51:42 | rgerganov | dansmith, there could be no way to calculate reserve without listing instances | |
| 13:52:06 | dansmith | reserved is a conf value | |
| 13:52:44 | bauzas | that's my whole point | |
| 13:52:46 | dansmith | you all were talking about other vms not owned by nova on a hypervisor right? and something external adding that value to reserved so nova doesn't try to use it, right? | |
| 13:52:53 | bauzas | reserved is set by the operator | |
| 13:53:08 | bauzas | so, if the operator wants to raise that value, fair enough | |
| 13:53:18 | dansmith | in that case, some other thing could be updating CONF.reserved_whatever and HUPing nova so that the next time the periodic runs, it just stabs the new scalar value into inventory.. no counting required. | |
| 13:53:19 | bauzas | but I don't see why Nova should care of thaty | |
| 13:53:24 | dansmith | bauzas: most definitely | |
| 13:53:26 | bauzas | dansmith: +1 | |
| 13:55:10 | mriedem | bauzas: in case you didn't see this https://bugs.launchpad.net/nova/+bug/1719730 | |
| 13:55:12 | openstack | Launchpad bug 1719730 in OpenStack Compute (nova) pike "Reschedule after the late affinity check fails with "'NoneType' object is not iterable"" [High,Confirmed] | |
| 13:55:19 | efried | As user experiences go, "Extend SAN disk, edit conf file, HUP n-cpu" ain't as friendly as "Extend SAN disk". | |
| 13:55:19 | mriedem | bauzas: melwitt might be working on a fix, i'm not sure | |
| 13:55:24 | mriedem | bauzas: but it's a regression in pike | |
| 13:55:32 | bauzas | mriedem: yup, I just provided my thoughts litterally 5 mins ago :p | |
| 13:55:53 | bauzas | mriedem: tl;dr I don't understand how we can get a ReqSpec group info that isn't accurate | |
| 13:55:54 | rgerganov | efried +1 | |
| 13:56:12 | dansmith | efried: nova wouldn't be reporting the inventory for a SAN disk, so no problem there :) | |
| 13:56:30 | dansmith | efried: and anything that an agent is surveying would be updated automatically | |
| 13:56:52 | dansmith | efried: if you hotplug some memory into your compute node, then nova-compute would automatically report that on the next periodic | |
| 13:57:19 | dansmith | efried: what you are talking about is updating the reserved value, which is static, operator-configured or operator-scripted | |
| 13:57:36 | mriedem | bauzas: provided your thoughts where? don't see anything in the bug or the linked pike change | |
| 13:57:39 | dansmith | efried: the HUP is so we notice the change to the config file.. certainly you don't want us to be live reloading the config file whenever we feel like it | |
| 13:57:54 | bauzas | mriedem: oh snap, duplicate bug | |
| 13:58:05 | bauzas | mriedem: https://bugs.launchpad.net/nova/+bug/1719859 | |
| 13:58:06 | openstack | Launchpad bug 1719859 in OpenStack Compute (nova) "Resize failure due to instance group being None in request spec" [Undecided,New] | |
| 13:58:30 | efried | dansmith Right, extending SAN was a bad example. | |
| 13:58:44 | bauzas | mriedem: mmm, nevermind, different issue, it seems | |
| 13:59:34 | efried | Not being super well-versed on how OVS comes into play for libvirt, can we apply the same principle to networking resources? | |
| 13:59:42 | mriedem | bauzas: ok, mel's is pretty straight forward | |
| 13:59:49 | mriedem | we used to set group_members in the filter_properties, | |
| 13:59:56 | mriedem | your change in pike stopped using filter_properties, | |
| 13:59:58 | efried | I.e. similar UX statement: "Do OVS thingy, edit conf file, HUP n-cpu" not as friendly as "Do OVS thingy" | |
| 14:00:02 | mriedem | but forgot to include the group_members stuff | |
| 14:00:12 | mriedem | she already said that the 1 line change fixes the issue | |
| 14:00:20 | mriedem | i just asked that a functional regression test get created | |
| 14:00:24 | bauzas | mriedem: okay, I'll wait for melwitt's patch | |
| 14:00:29 | dansmith | efried: no, nova-compute isn't reporting any network resources | |
| 14:00:53 | bauzas | mriedem: thanks for the catch | |