Switch from Openshift-SDN to OVN-kubernetes as networking plugin

[praveenkumar]

This doc contains support metrics for both the plugins for 4.13 and we also got some user who are interested to use ovn-kubernetes over openshift-sdn. This issue is just to check the user interest to switch it to ovn-kubernetes (upvote it if you want to see this default) .

In the past, we tried it and need to revert because of resource usage crc-org/snc#560 , we need to check if it is still the same or we need to increase default mem for openshift preset.

[cfergeau]

This doc contains support metrics for both the plugins for 4.13 and we also got some user who are interested to use ovn-kubernetes over openshift-sdn. This issue is just to check the user interest to switch it to ovn-kubernetes (upvote it if you want to see this default) .

In the past, we tried it and need to revert because of resource usage crc-org/snc#560 , we need to check if it is still the same or we need to increase default mem for openshift preset.

https://issues.redhat.com/browse/OCPBUGS-5945 was filed at the time, which concludes with:

If you have specific concerns about memory usage with OVNK ping me on slack. We have more lightweight modes for things like SNO and microshift to reduce memory footprint. I can also point you to SDN Perf/Scale engineers who can give you a better sense of the memory/cpu usage in relationship to cluster scale.

[gbraad]

We have more lightweight modes for things like SNO and microshift to reduce memory footprint.

How to activate those?

[praveenkumar]

How to activate those?

It should be automatic, I will check with OVN-K team to get more info if something else required around it.

[gbraad]

Something triggers this decision. I do not think our current setup does this, as so far we are seen as an 'OpenShift cluster', and not an SNO or MicroShift. Hope to learn more, ... perhaps Rom Feinmann can also help here.