So you have a 24x7 app.  What happens when maintenance needs to be done (rebuilding indexes can take hours!)?

Has anybody implemented a dynamic failover solution in a Seam app?  So perhaps you catch a SQLException (or a timeout or equivalent?) and throw the Exception and the client retries the method call.  You add a param to the signature of the DAO method called 'mode' or similar which specifies which datasource to utilize?

I will need to do this using JDBC (stored procs).  But even a generalized approach would be appreciated.  thx.