I'm using the version of hibernate that comes bundled with JBoss 4.2.1. I've deployed my application to multiple JBoss 4.2.1 servers. All of the servers are configured to use the same database. I can connect to one JBoss server, run some hibernate code and everything works fine. But when I connect to another JBoss server and run some hibernate code, I get 'Could not synchronize database state with session' errors.

17-10-2007 11:49:55 WARN SQL Error: 1062, SQLState: 23000
17-10-2007 11:49:55 ERROR Duplicate entry '109365' for key 1
17-10-2007 11:49:55 ERROR Could not synchronize database state with session

I assume that this is some sort of caching issue. Is it possible to point multiple JBoss instances at a single database? If so, what are the configuration steps?

I found the answer to my question.... use a replicated cache (i.e. JBoss Cache).

Information about this can be found on page 189 in "Hibernate in Action" and on the JBoss wiki: http://www.jboss.com/wiki/Wiki.jsp?page=JBossCache