Wrong version of an entity bean object being updated

Question

We are having a problem with an entity bean that uses bean managed persistence. The "order" entity bean has
been used as part of our Order Routing System for the last 2 years with no problems. The entity bean is
accessed via calls from a "Order Manager" session bean. No change has been done to the entity bean but the
frequency of calls from the session bean to update the entity bean have increased significantly.
The "order" entity bean wraps an Order object that contains order properties (i.e. id, quantity, price,
version, etc). The entity bean has a "void setOrder(Order param)" function that writes the Order to a database
and a "Order getOrder()" function that clones and returns the internal Order object. The "ejbLoad()" function
reads the Order object from the database and the "ejbStore()" function is not implemented.
The "OrderEntityPK ejbFindByPrimaryKey()" function checks if the order entity primary key (an "int") exists
on the database.
We are using the SilverStream 3.5 application server as our EJB container. According to the SilverStream manual
it does not maintain a pool of idle/unused entity beans, instead it instantiates beans as requested.
Our problem is:
1) The wrong version of the entity object is sometimes being updated (i.e. an old instance of the order entity is being
picked up and updated on the database).
2) We sometimes get a TransactionRequired exception thrown when we have concurrent updates to two different
objects of the entity bean.
Any idea as to what our problem could be?
Thanks in advance for your help,
The following are the main code snippets:
Original Code
Session Bean A
Method 1 --- gets entity Bean B and calls a method on a different object passing this entity bean
          in as a parameter to enable a method on this bean to be called.
EntityBean lOrderEntity = findOrderEntity(callerUnixLogin, currOrderId);
               currOrder = lOrderEntity.getOrder();
               //Logic to update the currOrder object via a method call.
               persistManager.persistOrder(lOrderEntity, callerUnixLogin, currOrder, psTransactionType);
     persistManager.persistOrder Method:
               lOrderEntity.setOrder(callerUnixLogin, order);
     findOrderEntity method:
OrderEntity lOrderEntity = null;
          OrderEntityBeanPK orderPK = new OrderEntityBeanPK(orderId);
          try
               if (orderEntityHome == null)
                    connectToOrderEntityBean(callerUnixLogin);
               lOrderEntity = orderEntityHome.findByPrimaryKey(orderPK);
          ... etc
Current Code
Session Bean C
Method 2 ---- calls method 1 in Session Bean A
Calls to method 2 above happens in quick succession.
OrderEntityBean class
... important methods ...
     private Order order = null;
     public OrderEntityBeanPK ejbFindByPrimaryKey(OrderEntityBeanPK primaryKey)
          throws FinderException, RemoteException, DBOException
          try
               orderObjectManager.orderIdExists(primaryKey.orderId);
          catch (OMOrderValidationException exc)
               throw new FinderException(exc.getMessage());
          return primaryKey;
     public void setOrder(String userUnixLogin, Order newOrder)
          throws EJBException, RemoteException, DBOException, OMFormattingException, OMOrderValidationException
          callerUnixLogin = userUnixLogin;
          int version = newOrder.getOrderVersion().intValue();
          if (order.getOrderVersion().intValue() == version)
               order = null;
               order = newOrder;
               Integer newVersion = new Integer(version + 1);
               order.setOrderVersion(newVersion);
               newVersion = null;
               order.setSysUser(callerUnixLogin);
               orderObjectManager.updateOrder(callerUnixLogin, order);
          else
               Debug.Print(userUnixLogin, "OrderEntityBean.setOrder: wrong version number for order " + newOrder.getOrdId() +
                    ": expected " + order.getOrderVersion() + " and got " + newOrder.getOrderVersion(), 0);
               throw new OMOrderValidationException("wrongVersion", order, order.getOrdId(), IName.Order.VERSION, newOrder.getOrderVersion());
     public Order getOrder()
          throws EJBException, RemoteException
return ((Order)order.clone());
The following transactions exists for the entity bean ...
Required:
     create and setOrder methods
Not Supported
     findByPrimary and getOrder methods

Answer 1

"The entity bean has a "void setOrder(Order param)" function that writes the Order to a database"
This functionality should be performed in the ejbStore method().
"a "Order getOrder()" function that clones and returns the internal Order object."
Sounds reasonable, except for the cloning part.
"The "ejbLoad()" function reads the Order object from the database"
Cool.
""ejbStore()" function is not implemented."
Whoops. Looks like your setOrder method is doing too much. It should do the inverse of getOrder (namely, setting the interal Order object), nothing more. Defer the persistence code to the ejbStore method.
"According to the SilverStream manual it does not maintain a pool of idle/unused entity beans, instead it instantiates beans as requested."
Manual? What's that? Assuming that is correct, better hope you don't ever get a high load. You might wanna look into JBoss.
"2) We sometimes get a TransactionRequired exception thrown when we have concurrent updates to two different objects of the entity bean."
How can you have concurrent access to two different objects?? Concurrency is inherently applicable to only one object.
In summary:
Write your beans properly, ejbLoad populates the bean with data, ejbStore persists the bean's data.
Get a better (and possibly free) appserver.