openstack team mailing list archive

[Vishvananda Ishaya <vishvananda@xxxxxxxxx>]

On Mar 2, 2012, at 2:11 PM, Duncan McGreggor wrote:

> On Fri, Mar 2, 2012 at 4:10 PM, Monsyne Dragon <mdragon@xxxxxxxxxxxxx> wrote:
>> 
>> 
>> Has anyone thought about switching to gevent?   It's similar enough to eventlet that the port shouldn't be too bad, and because it's event loop is in C, (libevent), there are C mysql drivers (ultramysql) that will work with it without blocking.
> 
> We've been exploring this possibility at DreamHost, and chatted with
> some other stackers about it at various meat-space venues. Fwiw, it's
> something we'd be very interested in supporting (starting with as much
> test coverage as possible of eventlet's current use in OpenStack, to
> ensure as pain-free a transition as possible).
> 
> d

I would be for an experimental try at this.  Based on the experience of starting with twisted and moving to eventlet, I can almost guarantee that we will run into a new set of issues.  Concurrency is difficult no matter which method/library you use and each change brings a new set of challenges.

That said, gevent is similar enough to eventlet that I think we will at least be dealing with the same class of problems, so it might be less painful than moving to something totally different like threads, multiprocessing, or (back to) twisted. If there were significant performance benefits to switching, it would be worth exploring.

I wouldn't want to devote a huge amount of time to this unless we see a significant reason to switch, so hopefully Jay gets around to testing it out.

Vish