When working at a client site we decided to enable Hibernate
statistics, so we can access all this information about cache
hits/misses, transactions, entities,… and all kind of cool stuff
through a JMX interface at runtime, allowing runtime configuration
changes and monitoring.

But seems that not many people is using this feature, because we
got the frustrating NullPointerException. After debugging a bit through
the Hibernate sources (if you have ever tried you know that it’s a PITA) I found the errors, same exception in two places,
and told JBoss support (the client was paying for it). Anyway I fixed them
locally while they fixed them in CVS, see the cvs diff or the JIRA issue. This bugs are present in hibernate 3.0.5 when using TreeCache.

Now we can get a lot of useful information at runtime, through a JMX console, I really like jManage,
mostly due to it’s cluster support, but you’ll need some tricks to make
it run with JBoss 4, that I’ll post in a separate entry.