Remote Queue Resolution

Remote queue resolution involves connection definitions and network resolution. We require a setup where there are two queue managers, one of which is the local queue manager that we use to put the message, and the other is the queue manager to which we want the message to go. Furthermore, we require that the remote queue manager has a listener, and that the local queue manager has a connection definition describing the listener, see Figure 58.

Figure 58. Local and remote queue managers with a definition and listener pair.


The connection definition/listener pair allows WebSphere MQ Everyplace to establish the network communications necessary to flow the message. The connection definition contains information about communicating with a single queue manager. The connection definition is named for the queue manager to which it defines a route. So in this example the connection definition is called TargetQM, and contains the information necessary to establish connection with (QueueManager)TargetQM. This information includes the address of the machine upon which the queue manager resides (remote host in this example), the port upon which the queue manager is listening (8081 in this example), and the protocol to use when conversing with the queue manager (FastNetwork in this example).

We need a remote queue reference on LocalQM representing the destination queue TargetQueue which resides on TargetQM. There are therefore two entities called TargetQueue@TargetQM. One is the 'real' queue, that is a local queue, and one is a reference to the real queue, a remote queue reference. Refer to Figure 59.

Figure 59. A remote queue reference.


The message resolution for a put on LocalQM to TargetQueue@TargetQM works as follows, see Figure 60.

Figure 60. Message resolution for a put.


The message route is as follows:

Although the connection definition and listener are vital to the message resolution they do not affect the routing in this example, and so we can omit them for the sake of clarity. See Figure 61.

Figure 61. Message resolution for a put


In later examples the connection definitions play a more important role and we will need to show them explicitly. For now we will assume the presence of the logical link formed by the listener and not show them in the diagrams. It is often much more convenient to use a simplified view of the message route. We can do this by thinking of the four elements that contribute to this message resolution as a single, composite, entity. This entity is a Message Route, see Figure 62.

Figure 62. A message route entity.


Here we see the message route that indicates that all messages put to LocalQM and addressed to TargetQueue@TargetQM will be moved directly to the destination. A Message Route is valid only if all the necessary components (Connection Definition, Listener, Remote Queue Definition, and destination queue) are present and correctly configured.

The Message Route is defined as a Push Message Route because messages are pushed from the source queue to the destination queue, by LocalQM.



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