This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
The message you are getting is not actually an "error" message. It is an informational message...the server is giving you an "oh, just so you know..." It doesn't necessarily denote any problem. Do you need clustering support? If you do I would refer you here.
subject: Domain does not support application server clusters and other standalone instances