On Thu, May 21, 2009 at 5:04 PM, Joe Armstrong <jarmstr...@postpath.com> wrote: > Hi All, > > I am a little confused about globally-unique clones, since there can be no > instance attributes for a clone how do you tell each clone that it is unique ?
The globally-unique=true option. Then, inside your resource agent, you need to set up a mapping between the instance number and the per-instance data. > My use case is that we need to run N instances of a mail server, each mail > server is unique in that it serves a specific domain, two mail server can > never run on the same host. In order to provide HA we need to tell the mail > server instance what domain to serve (or what filesystem to mount in order to > get the right data/config). > > I was thinking that using globally-unique clones would be the way to manage > this (it makes the mutual exclusion rule easy: clone-node-max=1) but I don't > see how to make each instance unique. > > ... then again I could be mis-using the concept... Its a valid use-case. As someone said below, you could set name="mydata" value="node1:www.example.com node2:www.example2.com node3:www.example3.com" convert that into an array and use the clone number to index into the array. Or set: name=domain0 value=www.example0.com name=domain1 value=www.example1.com name=domainN value=www.exampleN.com and simply look up the value of domain$CRM_meta_clone in the environment Just make sure you include error checking so that the cluster doesn't blow up if clone-max > number of domains. _______________________________________________ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
