I'm wondering when the session actually obtains the connection from the connection pool, b/c i'm seeing some situations when i "clean up" meaning flush(), commit() and close() the session, i'm getting an error on weblogic 8.1sp2 saying that the connection is no longer available.

the connections are pooled internally to weblogic using jndi set up in the context.xml file and this situation doesn't occur all the time, but say 1-in-10 times. The pool size i have set up is 25, which should be plenty. i've got the sessions bound to the thread-local on the httprequest, and the transactions aren't long running, so i don't believe that's the trouble, especially since more intense transactions don't always get this issue, but it can happen to even the most simple database insert

it's as if hibernate goes to use the connection that it assumes it already has, and weblogic seems to have reclaimed it so hibernate is blindsided by the fact that the connection is no longer there.

i'm just wondering if hibernate delays obtaining the connection until the very end (i.e., when it's ready to flush(), and write to the db) or if when the session is created, it retrieves the connection from the pool

thanks

Are you supplying your own connections to the Session? I guess so if you are using WebLogics connection pool. Maybe this might help you debug the problem... inside your getSession method where you return the thread-local call session.reconnect(), it is deprecated but it might give insight into what is going on. You could also add some debug code by using session.isConnected().

Not a solution, but hope it helps.

no, i'm not explicitly supplying my own connection. i'm simply getting the JNDI from weblogic, and then using spring's bean factory to inject it all together. thanks for the suggestion, however.

i'm just wondering when the session obtains the connection? initially when the session is created? or does the session delay obtaining the connection until it's absolutely necessary?

On looking up the source, it looks like the connection is obtained when the statement is prepared, which is at the very end. This is the case *unless* the user supplies a connection in which case it is obtained during Session Creation.
This makes sense as Hibernate doesnt have to lock connections unless its absolutely necessary to use them.