The way I'm setting this is the following:
I'm creating two JBAS configs on my clustered test target:
joss-jbmcluster1 and jboss-jbmcluster2
jbm-cluster1 will have a HSQLDB set, and jbm-cluster2 is connecting to jbm-cluster1 through regular IP.
I have tried to use what Brian had in place for Clustered tests, but I prefered this way, as it will be easier to migrate these tests into jboss-4.2.