> If we end up using a DLM then we have to detect when the connection to > the DLM is lost on a node and stop all ongoing operations to prevent > data corruption. > > It may not be trivial to do, but we will have to do it in any solution > we use, even on my last proposal that only uses the DB in Volume Manager > we would still need to stop all operations if we lose connection to the > DB.
Well, is it already decided that Pacemaker would be chosen to provide HA in Openstack? There's been a talk "Pacemaker: the PID 1 of Openstack" IIRC. I know that Pacemaker's been pushed aside in an earlier ML post, but IMO there's already *so much* been done for HA in Pacemaker that Openstack should just use it. All HA nodes needs to participate in a Pacemaker cluster - and if one node looses connection, all services will get stopped automatically (by Pacemaker) - or the node gets fenced. No need to invent some sloppy scripts to do exactly the tasks (badly!) that the Linux HA Stack has been providing for quite a few years. Yes, Pacemaker needs learning - but not more than any other involved project, and there are already quite a few here, which have to be known to any operator or developer already. (BTW, LINBIT sells training for the Linux HA Cluster Stack - and yes, I work for them ;) __________________________________________________________________________ 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