/**
  * PUBLIC: Disconnect from all databases.
  *
  * @exception EclipseLinkException if a transaction is active, you must rollback any active
  *     transaction before logout.
  * @exception DatabaseException the database will also raise an error if their is an active
  *     transaction, or a general error occurs.
  */
 public void logout() throws DatabaseException {
   for (Iterator sessionEnum = getSessionsByName().values().iterator(); sessionEnum.hasNext(); ) {
     DatabaseSessionImpl session = (DatabaseSessionImpl) sessionEnum.next();
     session.logout();
   }
   if (!isClientSessionBroker()) {
     if (hasExternalTransactionController()) {
       getExternalTransactionController().clearSequencingListeners();
     }
   }
   sequencing = null;
   isLoggedIn = false;
 }