Hi Vish, I completely agree, add more tests first and do it gradually. As Michael said we'll probably start with the rackspace/openstack API that Todd was working on to make sure it looks solid and integrates well, and then from there we can start with the other services.
-Eric On Wed, Aug 04, 2010 at 09:45:22AM -0700, Vishvananda Ishaya wrote: > If we are going to go through a major rewrite, I would suggest that we > spend some serious time improving our test coverage, especially > integration/smoketests. We need to know when our changes are breaking > things. Any manpower that we can devote to this now will dramatically > decrease the pain of switching over components in the future. I think > switching one component at a time is probably the right way to go as well. > Vish > On Wed, Aug 4, 2010 at 9:03 AM, Michael Gundlach > <[email protected]> wrote: > > All, > I propose that we go ahead and decide to use Eventlet. We've all had a > chance to talk, the decision isn't going to make itself, and it seems > like we're coalescing around Eventlet: > * In a long discussion about how to keep our code loosely coupled and > easy to maintain (see Architecture For Shared Components on the > openstack list), we concluded that WSGI would be a great solution, > and eday has prototyped an Eventlet-powered WSGI app talking AMQP to > Rabbit. The Twisted WSGI approach apparently isn't stable or > standard, but WSGI works just as you'd expect in Eventlet. > * As hazmat points out in the "twisted v. eventlet" thread, you can't > use pdb with Twisted, while pdb works just as you'd hope in > Eventlet. > * hazmat's experience during his lightning talk (see the same thread) > is a good datapoint verifying that people unfamiliar with either > project will probably prefer to work with Eventlet over Twisted: > good for recruiting. > * It's a weaker argument, but it's really hard to find any comparisons > between Twisted and Eventlet on the web that say Twisted is > preferable (has anyone found any?) > And as always, there's the argument that Eventlet code is easier to read > and understand, and therefore to maintain. > I'm going to be working on adding the RS API to Nova, and I'm going to > proceed in Eventlet. If anyone feels strongly that we must use Twisted > instead, speak up; otherwise, shall we call this decision made? > trying-to-build-consensus-ly yrs, > Michael > On Tue, Aug 3, 2010 at 8:13 AM, Soren Hansen > <[email protected]> wrote: > > On Mon, Aug 02, 2010 at 05:21:23PM -0500, Eric Day wrote: > > I took a closer look at the inner workings of how Twisted is > currently > > being used, and I think there is still a good chunk of work to be > done > > to make things work properly. For example, both Redis and AMQP > modules > > are not using the Twisted I/O event loop. Both are still issuing > sync > > socket calls in their own libs which could block the entire > > application. > > Yup, this definitely needs fixing. > > These things are very doable in Twisted, it will just require using > > the txRedis and txAMQP modules. It will also introduce more > deferreds > > into the mix since we'll have non-blocking connections dependent on > > each other. From this perspective, Eventlet may be easier since we > > could still use the current libraries by patching > > (http://eventlet.net/doc/patching.html). > > Yes, both python-redis and python-amqplib use Python's standard socket > module, so they can be patched. > > Does anyone know how eventlet would deal with libvirt calls? > python-libvirt just calls into libvirt obviously doesn't use Python's > socket module. > -- > Soren Hansen > Systems Architect > The Rackspace Cloud > > _______________________________________________ > Mailing list: https://launchpad.net/~nova > Post to : [email protected] > Unsubscribe : https://launchpad.net/~nova > More help : https://help.launchpad.net/ListHelp > > Confidentiality Notice: This e-mail message (including any attached or > embedded documents) is intended for the exclusive and confidential use of the > individual or entity to which this message is addressed, and unless otherwise > expressly indicated, is confidential and privileged information of Rackspace. > Any dissemination, distribution or copying of the enclosed material is > prohibited. > If you receive this transmission in error, please notify us immediately by > e-mail > at [email protected], and delete the original message. > Your cooperation is appreciated. > > _______________________________________________ > Mailing list: https://launchpad.net/~nova > Post to : [email protected] > Unsubscribe : https://launchpad.net/~nova > More help : https://help.launchpad.net/ListHelp > _______________________________________________ > Mailing list: https://launchpad.net/~nova > Post to : [email protected] > Unsubscribe : https://launchpad.net/~nova > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~nova Post to : [email protected] Unsubscribe : https://launchpad.net/~nova More help : https://help.launchpad.net/ListHelp
