+2 … Synchronous calls out to a separate service (glance-api) which then makes a synchronous call to a different service (glance-registry) all within a service serving a synchronous call (nova-api) makes the world slow.
On Jun 7, 2012, at 10:00 PM, Gabe Westmaas wrote: > Hey all, > > I was looking through some of the api calls, in particular creating a > server on the openstack api. I'm not too excited by how long it takes, > and was wondering what people think about making it more asynchronous. > Basically, wondering if making it so that the POST to the nova API doesn't > actually check to make sure we have a valid image, but instead just assume > the user knew what they were doing and pass the image down is something > that people buy. If the image is invalid (doesn't exist, no permission to > use that image, flavor size doesn't match the minimum requirements of the > image) then we would set the server to error and be done. > > There is an obvious drawback: losing the ability to fail fast. I think we > need to look at embracing the overall asynchronous nature of the API as > much as possible, and rely on client side tools to do upfront validation > where appropriate - nova client would already prevent this from happening > on a nonexistent image, for example. > > The API spec doesn't specify anything one way or the other about this - so > another route is to make this a configuration option. > > By the way, I don't want this to be construed in any way, shape or form as > me not wanting to improve the performance of glance. Of course we want > that, but we also know that any additional latency hurts performance. > > Thoughts? Are the benefits of fail fast out-weighing our performance > needs? > > > Gabe > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
