On Fri, Jul 31, 2015 at 01:47:22AM -0700, Mike Perez wrote: > On Mon, Jul 27, 2015 at 12:35 PM, Gorka Eguileor <gegui...@redhat.com> wrote: > > I know we've all been looking at the HA Active-Active problem in Cinder > > and trying our best to figure out possible solutions to the different > > issues, and since current plan is going to take a while (because it > > requires that we finish first fixing Cinder-Nova interactions), I've been > > looking at alternatives that allow Active-Active configurations without > > needing to wait for those changes to take effect. > > > > And I think I have found a possible solution, but since the HA A-A > > problem has a lot of moving parts I ended up upgrading my initial > > Etherpad notes to a post [1]. > > > > Even if we decide that this is not the way to go, which we'll probably > > do, I still think that the post brings a little clarity on all the > > moving parts of the problem, even some that are not reflected on our > > Etherpad [2], and it can help us not miss anything when deciding on a > > different solution. > > Based on IRC conversations in the Cinder room and hearing people's > opinions in the spec reviews, I'm not convinced the complexity that a > distributed lock manager adds to Cinder for both developers and the > operators who ultimately are going to have to learn to maintain things > like Zoo Keeper as a result is worth it. > > **Key point**: We're not scaling Cinder itself, it's about scaling to > avoid build up of operations from the storage backend solutions > themselves. > > Whatever people think ZooKeeper "scaling level" is going to accomplish > is not even a question. We don't need it, because Cinder isn't as > complex as people are making it. > > I'd like to think the Cinder team is a great in recognizing potential > cross project initiatives. Look at what Thang Pham has done with > Nova's version object solution. He made a generic solution into an > Oslo solution for all, and Cinder is using it. That was awesome, and > people really appreciated that there was a focus for other projects to > get better, not just Cinder. > > Have people consider Ironic's hash ring solution? The project Akanda > is now adopting it [1], and I think it might have potential. I'd > appreciate it if interested parties could have this evaluated before > the Cinder midcycle sprint next week, to be ready for discussion. > > [1] - https://review.openstack.org/#/c/195366/ > > -- Mike Perez
Hi all, Since my original proposal was more complex that it needed be I have a new proposal of a simpler solution, and I describe how we can do it with or without a DLM since we don't seem to reach an agreement on that. The solution description was more rushed than previous one so I may have missed some things. http://gorka.eguileor.com/simpler-road-to-cinder-active-active/ Cheers, Gorka. __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
