Passing messages through your system

You can pass messages through your system in three ways - using the location name, using an alias for the queue manager, or selecting a transmission queue.

Figure 1. Three methods of passing messages through your system
Three methods of passing messages through your system. Refer to the text following the diagram for details of the configuration shown.

The technique shown in Figure 1 in Receiving messages, showed how an alias flow is captured. Figure 1 illustrates the ways networks are built up by bringing together the techniques previously described.

The configuration shows a channel delivering three messages with different destinations:
  1. QB at QMC
  2. QB at QMD_norm
  3. QB at QMD_PRIORITY

You must pass the first message flow through your system unchanged. You must pass the second message flow through a different transmission queue and channel. For the second message flow you must also resolve messages for the alias queue manager name QMD_norm to the queue manager QMD. The third message flow chooses a different transmission queue without any other change.

In a clustering environment, messages are passed through a cluster transmission queue. Normally a single transmission queue, SYSTEM.CLUSTER.TRANSMIT.QUEUE, transfers all messages to all queue managers in all clusters that the queue manager is a member of; see A cluster of queue managers. You can define separate transmission queues for all or some of the queue managers in the clusters that the queue manager is a member of.

The following methods describe techniques applicable to a distributed-queuing environment.

Use these methods

For these configurations, you must prepare the:
  • Input channel definitions
  • Output channel definitions
  • Transmission queues:
    • QMC
    • TX1
    • QMD_fast
  • Queue manager alias definitions:
    • QMD_norm with QMD_norm to QMD through TX1
    • QMD_PRIORITY with QMD_PRIORITY to QMD_PRIORITY through QMD_fast
Note: None of the message flows shown in the example changes the destination queue. The queue manager name aliases provide separation of message flows.

Method 1: Use the incoming location name

You are going to receive messages with a transmission header containing another location name, such as QMC. The simplest configuration is to create a transmission queue with that name, QMC. The channel that services the transmission queue delivers the message unchanged to the next destination.

Method 2: Use an alias for the queue manager

The second method is to use the queue manager alias object definition, but specify a new location name, QMD, and a particular transmission queue, TX1. This action:
  • Terminates the alias message flow setup by the queue manager name alias QMD_norm, that is, the named class of service QMD_norm.
  • Changes the transmission headers on these messages from QMD_norm to QMD.

Method 3: Select a transmission queue

The third method is to have a queue manager alias object defined with the same name as the destination location, QMD_PRIORITY. Use the queue manager alias definition to select a particular transmission queue, QMD_fast, and therefore another channel. The transmission headers on these messages remain unchanged.