Diverting message flows to another destination

We can redefine the destination of certain messages using queue manager aliases and transmission queues.

Figure 1 illustrates how we can redefine the destination of certain messages. Incoming messages to QMA are destined for 'QB at QMC'. They normally arrive at QMA and be placed on a transmission queue called QMC which has 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 we 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

We must provide:

• Channel_back definition
• Queue manager alias object definition QMC with QB at QMD through 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

We can use aliases within a clustering environment. For information, see Queue manager aliases and clusters.

Parent topic: IBM MQ distributed queuing techniques