I get the following message several times a week:

2006-04-12 12:16:34,964 WARN [org.hibernate.util.JDBCExceptionReporter] SQL Error: -708, SQLState: 08000
2006-04-12 12:16:34,965 ERROR [org.hibernate.util.JDBCExceptionReporter] [-708] Data receive failed.
2006-04-12 12:16:34,987 ERROR [org.hibernate.transaction.JDBCTransaction] JDBC commit failed
com.sap.dbtech.jdbc.exceptions.ConnectionException: [-708] Could not send data.
at com.sap.dbtech.jdbc.ConnectionSapDB.execute(ConnectionSapDB.java:554)
at com.sap.dbtech.jdbc.ConnectionSapDB.execute(ConnectionSapDB.java:434)
at com.sap.dbtech.jdbc.ConnectionSapDB.executeSQLString(ConnectionSapDB.java:589)
at com.sap.dbtech.jdbc.ConnectionSapDB.commit(ConnectionSapDB.java:216)
at org.jboss.resource.adapter.jdbc.BaseWrapperManagedConnection.jdbcCommit(BaseWrapperManagedConnection.java:436)
at org.jboss.resource.adapter.jdbc.WrappedConnection.commit(WrappedConnection.java:331)
at org.hibernate.transaction.JDBCTransaction.commitAndResetAutoCommit(JDBCTransaction.java:139)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:115)
at gribupload.web.webwork.action.GribuploadAction.doExecute(Unknown Source)
...

At the same time the logmessages from our Databaseserver show:
...
2006-04-12 12:15:14 24 WNG 11824 COMMUNIC Releasing T227 command timeout
2006-04-12 12:15:14 24 12929 TASKING Task T227 started
2006-04-12 12:15:14 24 11007 COMMUNIC wait for connection T227
...

After this hibernate cannot receive/write to the database any more until I flush the ManagedConnectionPool using JBoss web-console.
The available connections count shown in the JBoss web-console show only a few connections in use and many possible connections left for use.

I cannot reproduce this starting several parallel connections to stress the Applicationserver.

How can I find out what is going wrong. I am using JBoss 4.0.3SP1 and MaxDB 7.6.0 .

Thanks
Werner Frerichs