Open Stack

All due respect to Zane who created the scheduler. We simply could not
do what we do without it (and I think one of the first things I asked
for was parallel create ;).

IMO it is the single most confusing thing in Heat whenever one has to
deal with it. If we could stick to a threading model instead, I would
much prefer that.

Excerpts from Joshua Harlow's message of 2014-02-06 10:22:24 -0800:
> Has there been any investigation into heat.
> 
> Heat has already used parts of the coroutine approach (for better or
> worse).
> 
> An example: 
> https://github.com/openstack/heat/blob/master/heat/engine/scheduler.py#L230
> 
> """
>     Decorator for a task that needs to drive a subtask.
> 
>     This is essentially a replacement for the Python 3-only "yield from"
>     keyword (PEP 380), using the "yield" keyword that is supported in
>     Python 2. For example::
> """....
> 
> 
> I bet trollius would somewhat easily replace a big piece of that code.
> 
> -Josh
> 
> -----Original Message-----
> From: victor stinner <victor.stinner at enovance.com>
> Reply-To: "OpenStack Development Mailing List (not for usage questions)"
> <openstack-dev at lists.openstack.org>
> Date: Thursday, February 6, 2014 at 1:55 AM
> To: "OpenStack Development Mailing List (not for usage questions)"
> <openstack-dev at lists.openstack.org>
> Subject: Re: [openstack-dev] Asynchrounous programming: replace eventlet
> with asyncio
> 
> >Sean Dague wrote:
> >> First, very cool!
> >
> >Thanks.
> >
> >> This is very promising work. It might be really interesting to figure
> >> out if there was a smaller project inside of OpenStack that could be
> >> test ported over to this (even as a stackforge project), and something
> >> we could run in the gate.
> >
> >Oslo Messaging is a small project, but it's more a library. For a full
> >daemon, my colleague Mehdi Abaakouk has a proof-on-concept for Ceilometer
> >replacing eventlet with asyncio. Mehdi told me that he doesn't like to
> >debug eventlet race conditions :-)
> >
> >> Our experience is the OpenStack CI system catches bugs in libraries and
> >> underlying components that no one else catches, and definitely getting
> >> something running workloads hard on this might be helpful in maturing
> >> Trollius. Basically coevolve it with a piece of OpenStack to know that
> >> it can actually work on OpenStack and be a viable path forward.
> >
> >Replacing eventlet with asyncio is a huge change. I don't want to force
> >users to use it right now, nor to do the change in one huge commit. The
> >change will be done step by step, and when possible, optional. For
> >example, in Olso Messaging, you can choose the executor: eventlet or
> >blocking (and I want to add asyncio).
> >
> >Victor
> >
> >_______________________________________________
> >OpenStack-dev mailing list
> >OpenStack-dev at lists.openstack.org
> >http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> 
> 
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