RE: [hibernate-dev] Connection release modes

I don't understand the statement about "auto-commit mode connection release". The idea with the implied auto-commit connection release mode is that in the case of auto-commit transaction control, there is really no need to have the same connection for each operation as long as we are not batching and not generally holding open JDBC resources. What makes you say it appears to happen for just a few operations? "With a Java transaction manager we have to give back the connection after every SQL statement" => That's not completely true. The reason we introduced this behavior was to circumvent "resource containment checks" in environments which do such things (JBoss, WebLogic and WebSphere app servers for example). "resource containment who-whats"? ;) Well there is a usage pattern which used to cause Hibernate users problems in such environments. Consider the case of an EJB application using Hibernate where the EJBs call one another; something like: SessionBeanA { public void doSomething() { Session s = ...; SessionBeanB b = ...; b.doSomethingElse(); } } SessionBeanB { public void doSomethingElse() { Session s = ...; s.load( MyEntity.class, "myKey" ); // do some more work and return } } Pretty innocuous, right? The problem lies in the fact that the Session did not actually obtain a JDBC connection until the execution of SessionBeanB.doSomethingElse() since it delays getting a connection until needed. The problem, from the perspective of environments which do perform resource containment checks, is that we just leaked a resource... the connection! The connection was retrieved from the DS during the execution of SessionBeanB.doSomethingElse(), but is not released by the time SessionBeanB.doSomethingElse() completes execution. And just to round out the discussion, I do not know how this works in the .Net corollaries, but after_transaction should not be used in the case of some form of managed transaction and transacted datasources. Doing so would cause Hibernate to try and release its connection handle during the Synchronization.afterCompletion callback, which is disallowed. -----Original Message----- From: hibernate-dev-bounces(a)lists.jboss.org [mailto:hibernate-dev-bounces@lists.jboss.org] On Behalf Of Christian Bauer Sent: Wednesday, December 13, 2006 5:56 AM To: the NHibernate development list; hibernate Subject: [hibernate-dev] Connection release modes Bringing the two lists together for this thread. On Dec 13, 2006, at 12:01 PM, Sergey Koshcheyev wrote: _______________________________________________ hibernate-dev mailing list hibernate-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev