Hi Friends

I have some serious issues with hibernate, specially concurrent operations, coming nearly at same time

when two transactions come at same time, sometimes one of them throws an exception indicating that the session is closed. And sometimes both sessions are closed

why when i'm using concurrent requests one or both sessions are closed?

i hope you can help me

Hibernate version:

3.1.3

Hbernate configuration:

<session-factory >

<!-- DESARROLLO -->
<property name="hibernate.default_schema">SQMPP</property>
<property name="hibernate.dialect">org.hibernate.dialect.DB2Dialect</property>
<property name="hibernate.connection.datasource">jdbc/DBVPOS</property>
<property name="hibernate.show_sql">false</property>
<property name="hibernate.transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</property>

<property name="jta.UserTransaction">java:comp/UserTransaction</property>

<property name="hibernate.session_factory_name">HibernateSessionFactory</property>

<property name="hibernate.transaction.manager_lookup_class">org.hibernate.transaction.WebSphereTransactionManagerLookup</property>
<property name="hibernate.cglib.use_reflection_optimizer">true</property>
<property name="hibernate.connection.release_mode">after_statement</property>
<property name="hibernate.connection.autocommit">false</property>
<property name="hibernate.cache.use_query_cache">true</property>
<property name="hibernate.cache.provider_class">net.sf.ehcache.hibernate.EhCacheProvider</property>



<property name="hibernate.connection.isolation">1</property>

...

</session-factory>


Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:
2006-08-03 12:13:10,368 - ACQ: 3 COM: 1259 ORD: 1154625178990 - ERROR - INIT - Error general
org.hibernate.SessionException: Session is closed
at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:126)
at org.hibernate.transaction.JDBCTransaction.rollbackAndResetAutoCommit(JDBCTransaction.java:183)
at org.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:162)
at com.alignet.vpos.multimarca.action.TransactionStartAction.saveReservedData(TransactionStartAction.java:949)
at com.alignet.vpos.multimarca.action.TransactionStartAction.execute(TransactionStartAction.java:529)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.ibm.ws.webcontainer.servlet.StrictServletInstance.doService(StrictServletInstance.java:110)
at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet._service(StrictLifecycleServlet.java:174)
at com.ibm.ws.webcontainer.servlet.IdleServletState.service(StrictLifecycleServlet.java:313)
at com.ibm.ws.webcontainer.servlet.StrictLifecycleServlet.service(StrictLifecycleServlet.java:116)
at com.ibm.ws.webcontainer.servlet.ServletInstance.service(ServletInstance.java:283)
at com.ibm.ws.webcontainer.servlet.ValidServletReferenceState.dispatch(ValidServletReferenceState.java:42)
at com.ibm.ws.webcontainer.servlet.ServletInstanceReference.dispatch(ServletInstanceReference.java:40)
at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.handleWebAppDispatch(WebAppRequestDispatcher.java:1171)
at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:676)
at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:203)
at com.ibm.ws.webcontainer.srt.WebAppInvoker.doForward(WebAppInvoker.java:125)
at com.ibm.ws.webcontainer.srt.WebAppInvoker.handleInvocationHook(WebAppInvoker.java:300)
at com.ibm.ws.webcontainer.cache.invocation.CachedInvocation.handleInvocation(CachedInvocation.java:71)
at com.ibm.ws.webcontainer.srp.ServletRequestProcessor.dispatchByURI(ServletRequestProcessor.java:246)
at com.ibm.ws.webcontainer.oselistener.OSEListenerDispatcher.service(OSEListener.java:334)
at com.ibm.ws.webcontainer.http.HttpConnection.handleRequest(HttpConnection.java:56)
at com.ibm.ws.http.HttpConnection.readAndHandleRequest(HttpConnection.java:652)
at com.ibm.ws.http.HttpConnection.run(HttpConnection.java:448)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:936)

Name and version of the database you are using:
DB2 8.2.5

The generated SQL (show_sql=true):

Debug level Hibernate log excerpt: