Do you use the default connection factories provided with the J2EE Engine?

We recommend that you use the default connection factories provided by the J2EE Engine, located in jmsfactory/default/TopicConnectionFactory or jmsfactory/default/QueueConnectionFactory.

Did you close the JMS connection correctly?

When you implement the onException() method, do not close the client connections that were used up to that moment. The JMS Provider takes care of that. The client has to get the objects he or she requires from the factory that was already obtained.

Are you using message delivery limitation on a point-to-point scenario?

When using message delivery attempts limitation, remember it is supported only for point-to-point scenarios.

Are you using more than one durable subscriber?

When using durable subscribers, remember that a durable subscription can have only one active subscriber at a time.

Are you applying security restrictions over the JMS connections?

No encryption is available on the JMS communication. Even though the binary format is hard to decode this may imply a security risk if messages contain sensitive information.