MQ can be integrated with Enterprise Server in three ways: LOCAL, REMOTE, and EMBEDDED. These modes are represented in the Admin Console by the Java Message Service Type attribute.
When the Type attribute is LOCAL (the default for cluster instances), the Enterprise Server will start and stop the MQ broker specified as the Default JMS host. The MQ process is started out-of-process, in a separate VM, from the appliciation server process. Enterprise Server supplies an additional port to the broker . This port will be used by the broker to start the RMI registry. This port number will be equal to the configured JMS port for that instance plus 100. For example, if the JMS port number is 37676, then this additional port number will be 37776.
To create a one-to-one relationship between Enterprise Server instances and Message Queue brokers, set the type to LOCAL and give each Enterprise Server instance a different default JMS host. You can do this regardless of whether clusters are defined in the Enterprise Server or MQ.
With LOCAL type, use the Start Arguments attribute to specify MQ broker startup parameters.
When the Type attribute is REMOTE, the MQ broker must be started separately. For information about starting the broker, see the Sun GlassFish Message Queue Administration Guide.
In this case, Enterprise Server will use an externally configured broker or broker cluster. Also, you must start and stop MQ brokers separately from Enterprise Server, and use MQ tools to configure and tune the broker or broker cluster. REMOTE type is most suitable for Enterprise Server clusters.
With REMOTE type, you must specify MQ broker startup parameters using MQ tools. The Start Arguments attribute is ignored.
When the JMS Type attribute is EMBEDDED, it means that the Enterprise Server and the JMS broker are co-located in the same VM and the JMS service is started in-process and managed by the Enterprise Server. In this mode, the JMS operations by pass the networking stack leading to performance optimization.