Diverting message flows to another destination

Figure 25. Diverting message streams to another destination

Figure 25 illustrates how you can redefine the destination of certain messages. Incoming messages to QMA are destined for 'QB at QMC'. They would normally arrive at QMA and be placed on a transmission queue called QMC which would have been part of a channel to QMC. QMA must divert the messages to QMD, but is able to reach QMD only over QMB. This method is useful when you need to move a service from one location to another, and allow subscribers to continue to send messages on a temporary basis until they have adjusted to the new address.

The method of rerouting incoming messages destined for a certain queue manager to a different queue manager uses:

• A queue manager alias to change the destination queue manager to another queue manager, and to select a transmission queue to the adjacent system
• A transmission queue to serve the adjacent queue manager
• A transmission queue at the adjacent queue manager for onward routing to the destination queue manager

You must provide:

• Channel_back definition
• Queue manager alias object definition QMC with QB at QMD via QMB
• Channel_out definition
• The associated transmission queue QMB

The complementary administrator who is configuring QMB must provide:

• The corresponding channel_back definition
• The transmission queue, QMD
• The associated channel definition to QMD

You can use aliases within a clustering environment. For information about this, see the WebSphere MQ Queue Manager Clusters book.