I have having this huge problem with OBIEE 11G clustering. I have managed to create a unclustered DSN but I get an error when I try to execute a agent. I have learnt that setting PartOfCluster in instanceconfig.xml will fix this problem. The issue is that the value of PartOfCluster tag is changed to the default value on every restart of BI services. I couldn't find a place in the FMW where I could change this.