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#openstack-nova - 2019-02-15
15:05:49 mriedem "Custom resource classes and standard resource classes to override"
15:05:56 mriedem yeah
15:05:57 mriedem resources:CUSTOM_BAREMETAL_SMALL=1 resources:VCPU=0
15:06:03 edleafe That was how it was supposed to be done. Keep the values in the flavor, and zero out in extra_specs
15:06:40 mriedem ok i don't know why that standard resource class 0 override wasn't done at the same time as the embedded instance.flavor migration once the node was reporting a custom resource class
15:07:16 mriedem plus that's what the ironic docs tell operators to do https://docs.openstack.org/ironic/latest/install/configure-nova-flavors
15:07:41 edleafe mriedem: https://docs.openstack.org/ironic/latest/install/configure-nova-flavors describes it pretty well
15:07:55 edleafe jinx
15:08:45 dansmith mriedem: yeah, for display and to avoid triggering any of our other magic behaviors with a value is zero, like root size
15:09:21 mriedem sure but we can override via the extra spec
15:09:24 mriedem that seems to be the missing piece
15:09:43 mriedem now whether or not the code that's reporting allocations actually looks at that override...
15:09:50 dansmith right, the point being.. leave the real values for display, override what we actually ask for in the resource overrides
15:11:23 mriedem ok i think this is where the override happens https://github.com/openstack/nova/blob/stable/rocky/nova/scheduler/utils.py#L366
15:22:06 mriedem belmoreira: ok i'm working on a patch which you can take a look at - knowing this isn't all totally fubar will require a functional test though given how tightly coupled all of this is between the virt driver, resource tracker and scheduler
15:37:07 belmoreira mriedem: thanks
15:38:03 mriedem the commit message on this is going to be fun
15:38:37 mriedem "first belmiro lost a finger here, and then he blew off a toe here"
15:39:52 belmoreira as you may noticed I upgraded nova-compute for ironic only today :) as been an interesting day
15:40:50 belmoreira the next issue is: https://bugs.launchpad.net/nova/+bug/1816086
15:40:51 openstack Launchpad bug 1816086 in OpenStack Compute (nova) "Resource Tracker performance with Ironic driver" [Undecided,New]
15:41:01 fried_rice uh oh
15:41:50 fried_rice I thought I fixed that. belmoreira are you using latest master?
15:42:09 mriedem he's upgrading ironic queens to rocky i assume
15:42:11 mriedem for compute services
15:42:22 mriedem so they would have had to backport your patches
15:42:22 fried_rice oh, that'd do it
15:42:25 fried_rice yeah
15:42:55 belmoreira I'm using rocky (back ported the patches that we discussed in the past)
15:43:23 melwitt
15:45:13 belmoreira fried_rice: so what I'm saying in the bug doesn't make sense anymore?
15:45:32 fried_rice belmoreira: Backported which patches, though?
15:45:51 belmoreira we couldn't cherrypick the patches in a clean way, we may have missed something
15:45:53 fried_rice belmoreira: Latest master has changes that made sure to only update the ironic node being touched.
15:46:05 fried_rice let me find the patch that did that...
15:47:20 fried_rice belmoreira: https://review.openstack.org/#/c/615677/
15:49:01 fried_rice belmoreira: I think if you picked that up prior to about PS17, you would have the ironic explosion behavior you're seeing. But after that it *should* be fixed.
15:49:06 jaypipes gibi: hmm, couldn't my algorithm work if we just sorted the request groups in descending order of amount of resources being requested in the group?
15:49:24 jaypipes gibi: then the "greedy" approach would work fine, no?
15:49:40 fried_rice belmoreira: and I know you guys were picking up that series at various points along the way
15:49:44 gibi jaypipes: if only one resource class would be used then yes, but if you have two resource classes requested then which one would sorted first?
15:50:23 fried_rice jaypipes: I didn't feel strongly enough to say so in the review, but fwiw I liked gibi's algorithm as is.
15:50:24 jaypipes gibi: do we have tests that show the behaviour or your algorithm is correct for such situations?
15:50:24 belmoreira fried_rice: thanks, I'm checking
15:50:35 tssurya fried_rice: porting was done after that patch got merged
15:50:41 jaypipes fried_rice: it's difficult to read and understand, IMHO.
15:50:44 fried_rice tssurya: roger that, thanks.
15:51:03 fried_rice jaypipes: I don't disagree, but I'm not sure yours is more readable/understandable. (It is to you because you formulated it.)
15:51:15 jaypipes fried_rice: as is most things around multiple use_single_provider request groups, FWIW
15:51:22 gibi jaypipes: it worth to step through https://review.openstack.org/#/c/616239/26/nova/tests/unit/objects/test_request_spec.py@1305
15:52:05 fried_rice tssurya: How far up the series did you port?
15:52:41 gibi jaypipes: there group1 could be fit first to 3 RPs but finally only the RP #3 leads to solution
15:54:18 jaypipes fried_rice, gibi: this all just leaves an odd taste in my mouth.
15:54:44 jaypipes fried_rice, gibi: a taste that says "oh, we're totally leaking the placement selection details out of the placement API"
15:54:51 gibi jaypipes: totally agree
15:54:53 jaypipes and yes, I understand this is a workaround
15:54:57 fried_rice jaypipes: Yeah, it sucks, but is hopefully temporary, to be whacked when placement lets ... just so
15:55:20 jaypipes until such point that the result of allocation_candidates contains an indicator of which request group "belongs" to which allocation provider
15:55:34 gibi jaypipes: yes
15:55:36 fried_rice So let's get that spec pushed through so we can implement it early in Train and get rid of this spaghetti.
15:55:44 jaypipes ack, ok
15:56:06 gibi fried_rice: unfortunately I cannot focus both on that spec and the bandwidth series at the same time (I'm limited)
15:56:14 gibi fried_rice: but after feature freeze I can update the spec
15:56:15 fried_rice gibi: Would you like me to take over that spec?
15:56:34 jaypipes gibi, fried_rice: question for you... are different request groups containing same resource class requests guaranteed to land on different resource providers?
15:56:40 gibi fried_rice: if it is OK to push it after the feature freeze then I'd like to keep the spec
15:56:46 jaypipes (I can never remember...)
15:56:49 fried_rice jaypipes: if group_policy=none, no
15:57:02 jaypipes ah, yes, group_policy=isolate..
15:57:28 jaypipes gibi, fried_rice: is group_policy=isolate taken account of in this mapping patch?
15:57:29 fried_rice gibi: okay. Yes, that should be fine. Just lmk if you want help (other than review)
15:57:40 fried_rice jaypipes: oo, good question.
15:57:44 jaypipes or does it even need to be? /shurg
15:57:46 gibi fried_rice: thanks, I will need you review! :)
15:58:06 fried_rice jaypipes: I think it might need to be, yes.
15:58:07 gibi jaypipes, fried_rice: bahh, good question
15:58:13 belmoreira fried_rice: what is taking time is the last for in the update_from_provider_tree
15:58:47 fried_rice as is, gibi's algorithm takes the first of many possible matchups; but it assumes group_policy=none
15:58:58 jaypipes yeah
15:59:01 belmoreira https://github.com/openstack/nova/blob/d231a420d0d4865bb19da513af416cb8bc89010f/nova/scheduler/client/report.py#L1439
15:59:03 gibi fried_rice, jaypipes: if the request was made with isolate but the algo founds an overlapping solution then we are screwed
15:59:17 gibi fried_rice: correct
15:59:28 gibi fried_rice: so I have to enhance this algo
15:59:32 gibi fried_rice: to handle isolate
15:59:48 gibi fried_rice: and in that case throw away overlapping solutions
16:00:04 fried_rice gibi: correct
16:00:08 jaypipes gibi, fried_rice: well, maybe... maybe not. :) after all, we *KNOW* that the returned allocations properly meet the group_policy=isolate constraint because the placement service is shown to be correct in that.
16:00:58 fried_rice mm, nooo, I still think there's a hole
16:01:05 jaypipes so we can assume that the provider that is assigned a particular amount of allocated resources does not have any "doubled up" allocations from multiple request groups, right?
16:01:47 gibi in case of isolate, yes
16:01:50 fried_rice belmoreira: noted
16:01:56 jaypipes this is what's "eww" about this... :) it's essentially needing to re-implement the entire request group selection algorithm that's in the placement service already. :)
16:02:06 fried_rice belmoreira: because new_uuids == {every ironic node}
16:02:12 fried_rice jaypipes: Exactly.
16:02:19 gibi jaypipes: you are totatlly right
16:02:21 belmoreira fried_rice: correct
16:02:23 fried_rice jaypipes: and we haven't even done forbidden traits and aggregates yet
16:02:40 gibi fried_rice: and I hope we never have to in this algo
16:03:19 fried_rice belmoreira: set_inventory_for_provider et al should be shorting out, not talking to the placement API, for any but the changed node. Are you seeing those hit placement?
16:03:55 gibi so I need to found an example where there is two possible valid mapping one with overlap between groups and one without. If I can make such an example then I need to change the algo

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