On Thu, Aug 11, 2011 at 9:23 PM, pskrap <psk...@hotmail.com> wrote: > Andrew Beekhof <andrew@...> writes: > >> >> On Thu, Jul 21, 2011 at 4:13 PM, pskrap <pskrap@...> wrote: >> > Devin Reade <gdr@...> writes: >> > >> >> >> >> --On Wednesday, July 20, 2011 09:19:33 AM +0000 pskrap <pskrap@...> >> >> wrote: >> >> >> >> > I have a cluster where some of the resources cannot run on the same >> >> > node. >> >> > All resources must be running to provide a functioning service. This >> >> > means that a certain amount of nodes needs to be up before it makes >> >> > sense for the cluster to start any resources. >> >> >> >> Without knowing anything about your application, I would tend to question >> >> this statement. Is it true that you must not start *any* resources before >> >> you have enough nodes, or is sufficient to say that the application >> >> is not considered up until all resources are started? It may not >> >> make sense to run any, but does it do any harm? >> >> >> >> If you *can* start at least some resources before all nodes are available, >> >> then I would expect that you could get by with defining colocation >> >> constraints to ensure that some resources don't run on the same nodes, >> >> perhaps augmenting things with some order constraints if necessary. >> >> >> >> If your applications die or do other horrible stuff when only some subset >> >> are running then I'd have a talk with your application developers >> >> as it sounds like a larger robustness problem. >> >> >> >> Devin >> >> >> > >> > No, there are no crash issues etc when all resources are not running. The >> > application is just not usable until all resources are started. >> > >> > As for the harm, the resources which have constraints preventing them from >> > running will fail, >> >> Are you talking about constraints in the pacemaker config or some other kind? > > I was talking about pacemaker config constraints.
Doesn't sound very highly available though - if a failure in one node makes the cluster useless. > > I found that by manually updating the expected-quorum-votes property to the > number of nodes I want to install I can prevent pacemaker from reaching quorum > early. It does not seem to update this property until the number of nodes > reaches its number. Using this slight hack, pacemaker wont try to start > anything until I have installed enough nodes. > > Another solution which may be better is to just to simply set the property > stop- > all-resources=true until the last machine is installed and then set it to > false, causing everything to start. That sounds like a better match for what you're trying to achieve. > > > > > _______________________________________________ > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: > http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker > _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
