Andrew Beekhof <beekhof@xxxxxxxxx> 2008-11-28 08:50: > On Thu, Nov 27, 2008 at 15:57, Brian Kroth <bpkroth@xxxxxxxxx> wrote: > > Hello all, > > > > I've been using Heartbeat in past to do resource failover with the > > following scheme: > > > > 1) Each node in the cluster runs a dummy monitoring resource agent as a > > clone. This resource agent monitors the health of a service on the node > > using whatever rules one wants to write into it. For instance, make > > sure the service is not in maintenance mode, mysql is running, queries > > return timely, and replication is up to date. If all the checks pass it > > uses attrd_updater to set an attribute for that service on the node to > > 1. Else, it is set to 0. Note that this resource agent in no way > > affects the service it is monitoring. > > > > 2) The cluster configuration uses the attributes for each of the > > monitored services to generate a score for the machine. The machine > > with the highest score gets to host the virtual ip for that service. > > > > This scheme allows one to, for instance, touch a file on a machine that > > will signify that it's in maintenance mode. The service ip would then > > be moved to another node, leaving one to test out the service on the > > machine's management ip without removing it from the cluster itself > > which would cause a lack of gfs access. It also provides for more > > granular monitoring of each service. > > > > I want to know how I would configure rgmanager with something similar to > > this - to have resource agents that continually monitor the status of a > > service on each node and then move service IPs accordingly. > > Just out of interest, where did the rgmanager requirement come from? > > <blatant-advertisement> > The Heartbeat resource manager also runs on OpenAIS now which, IIRC, > is what rgmanager uses... so, in theory, it can manage anything > rgmanager can. > </blatant-advertisement> I think that's still in development, but I may be wrong. If it's the case I'll look back into it. rgmanager is not a requirement. I'm just curious if I can get by running one cluster stack instead of two. It occurred to me last night that I might be able to cook something up that used ccs_tool to adjust the priorities of a node in a failover domain. I'll report back if this works out. I haven't done any further research yet. > > I see that one can write their own agents, but I don't see a scoring > > scheme anywhere. My concern is that if I simply write an agent to > > monitor a service and have an ip depend upon the return code of that > > monitoring agent the service would not ever be failed back to the > > original host. > > > > Does this make sense? > > > > Thanks, > > Brian > > > > -- > > Linux-cluster mailing list > > Linux-cluster@xxxxxxxxxx > > https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
