Hi,
Wiadomość napisana przez David G. Bingham <dbingham@godaddy.com> w dniu 01.02.2019, o godz. 19:16:
Neutron land,
Problem: Neutron currently only allows a single network segment per host. This becomes a problem when networking teams want to limit the number of IPs it supports on a segment. This means that at times the number of IPs available to the host is the limiting factor for the number of instances we can deploy on a host. Ref: https://bugs.launchpad.net/neutron/+bug/1764738
Ongoing Work: We are excited in our work add "multi-segment support for routed networks". We currently have a proof of concept here https://review.openstack.org/#/c/623115 that for routed networks effectively: * Removes validation preventing multiple segments. * Injects segment_id into fixed IP records. * Uses the segment_id when creating a bridge (rather than network_id). In effect, it gives each segment its own bridge.
It works pretty well for new networks and deployments. For existing routed networks, however, it breaks networking. Please use *caution* if you decide to try it.
TODOs: Things TODO before this before it is fully baked: * Need to add code to handle ensuring bridges are also updated/deleted using the segment_id (rather than network_id). * Need to add something (a feature flag?) that prevents this from breaking routed networks when a cloud admin updates to master and is configured for routed networks. * Need to create checker and upgrade migration code that will convert existing bridges from network_id based to segment_id based (ideally live or with little network traffic downtime). Once converted, the feature flag could enable the feature and start using the new code.
Need: 1. How does one go about adding a migration tool? Maybe some examples?
I’m not sure if this can be similar but I know that networking-ovn project has some migration tool to migrate from ml2/ovs to ml2/ovn solution. Maybe this can be somehow helpful for You.
2. Will nova need to be notified/upgraded to have bridge related files updated?
Probably someone from Nova team should answer to that. Maybe Sean Mooney would be good person to ask?
3. Is there a way to migrate without (or minimal) downtime? 4. How to repeatably test this migration code? Grenade?
Again, check how networking-ovn did it, maybe You will be able to do something similar :)
Looking for any ideas that can keep this moving :)
Thanks a ton,
David Bingham (wwriverrat on irc) Kris Lindgren (klindgren on irc) Cloud Engineers at GoDaddy
— Slawek Kaplonski Senior software engineer Red Hat