One of our customers asked me exactly this question. They have an Oracle ESB and it seemed that it could not handle all incoming requests. With the queues being a decoupling point between the incoming requests and the related transactions to the back office systems, its size can be an indication of just how busy the system is.
As I couldn’t find the answer using the Oracle Enterprise Manager Oracle Enterprise Manager and its MBeans, I started to look on the web for a tool. The tool I found and started to use was HermesJMS. This helps you interact with JMS providers making it easy to browse or search queues and topics, copy messages around and delete them.
The HermesJMS requires Java 1.6. It has a clear installation guide installation guide and it is tested for multiple JMS providers. Besides the guide we needed for the Oracle AS there is also another blog describing the install and use of HermesJMS.
Using HermesJMS we were able to answer this customers question.