Bug 2120410

Summary:	[17.0 ga tech preview] Scheduler support for routed networks
Product:	Red Hat OpenStack	Reporter:	Artom Lifshitz <alifshit>
Component:	openstack-nova	Assignee:	OSP DFG:Compute <osp-dfg-compute>
Status:	CLOSED CURRENTRELEASE	QA Contact:	OSP DFG:Compute <osp-dfg-compute>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	17.0 (Wallaby)	CC:	dasmith, eglynn, igallagh, jhakimra, kchamart, sbauza, sgordon, smooney, vromanso
Target Milestone:	ga	Keywords:	TechPreview, Triaged
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Technology Preview
Doc Text:	In Red Hat OpenStack Platform 17.0, a technology preview is available for Compute service scheduling based on routed networks. Network segments are reported to the Placement service as host aggregates. The Compute service includes the network segment information in the Placement service query to ensure that the selected host is connected to the correct network segment. This feature enables more accurate scheduling through better tracking of IP availability and locality, and more accurate instance migration, resizing, or unshelving through awareness of the routed network IP subnets.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-09-12 15:20:11 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Artom Lifshitz 2022-08-22 20:26:21 UTC

This bug was initially created as a copy of Bug #1761903

I am copying this bug because:

As we haven't had capacity to QE this, need a release note for tech preview in 17.0 ga.

Description of problem:

Routed network support was originally added upstream in newton (osp 10)

https://specs.openstack.org/openstack/nova-specs/specs/newton/implemented/neutron-routed-networks.html

customer have requestied that this feature be supproted in OSP and work is underway to enable it

https://bugzilla.redhat.com/show_bug.cgi?id=1671811
https://bugzilla.redhat.com/show_bug.cgi?id=1721113

the current implemeantion of routed network relys on the use of ip_allocation=defer which requried the ip to be assigned only after
a host is selected because the nova schduler and placment is not aware
of the subnet affinity between netwrok segment and compute host.

work is underway to report netwrok segments to palcement as aggregtes
but to complete the integration work is need in nova to be able to
include segment infomraiton in the placmenet query such that we can guarentee
that the the select host will be conented to the correct neutron segment.

this will allow better tacking of ip aviablity and ip locality enabling
more accurate scheduling and will enable nova and placmenet to be aware
of ip subnet restriction wehn migrating, resizing or unshelveing instances.

To achive this nova need to be enhanced to schdule based on routed networks.

This is an important usecase for edge deployments.

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Comment 1 Artom Lifshitz 2022-09-12 15:20:11 UTC

The release notes automation will pick up BZs with the right flags even if they're closed. With the doc text done and requires_doc_text set to +, we can close this.