Open Stack

> This seemed like a good time to finally revisit
> https://review.opendev.org/c/openstack/devstack/+/676016 (the OSC as a 
> service patch). Turns out it wasn't as much work to reimplement as I
> had expected, but hopefully this version addresses the concerns with
> the old one.
>
> In my local env it takes about 3:45 off my devstack run. Not a huge
> amount by itself, but multiplied by thousands of jobs it could be 
> significant.

I messed with doing this myself, I wish I had seen yours first. I never
really got it to be stable enough to consider it usable because of how
many places in devstack we use the return code of an osc command. I
could get it to trivially work, but re-stacks and other behaviors
weren't quite right. Looks like maybe your version does that properly?

Anyway, I moved on to a full parallelization of devstack, which largely
lets me run all the non-dependent osc commands in parallel, in addition
to all kinds of other stuff (like db syncs and various project
setup). So far, that effort is giving me about a 60% performance
improvement over baseline, and I can do a minimal stack on my local
machine in about five minutes:

https://review.opendev.org/c/openstack/devstack/+/771505/

I think we've largely got agreement to get that merged at this point,
which as you say, will definitely make some significant improvements
purely because of how many times we do that in a day. If your OaaS can
support parallel requests, I'd definitely be interested in pursuing that
on top, although I think I've largely squeezed out the startup delay we
see when we run like eight osc instances in parallel during keystone
setup :)

--Dan