Restrictions and Optimizations

This section discusses restrictions on developing session beans and provides some optimization guidelines:

• Optimizing Session Bean Performance

• Restricting Transactions

Optimizing Session Bean Performance

For stateful session beans, colocating the stateful beans with their clients so that the client and bean are executing in the same process address space improves performance.

Restricting Transactions

The following restrictions on transactions are enforced by the container and must be observed as session beans are developed:

• A session bean can participate in, at most, a single transaction at a time.

• If a session bean is participating in a transaction, a client cannot invoke a method on the bean such that the trans-attribute element in the ejb-jar.xml file would cause the container to execute the method in a different or unspecified transaction context or an exception is thrown.

• If a session bean instance is participating in a transaction, a client cannot invoke the remove method on the session object’s home or component interface object or an exception is thrown.