This Part provides the foundation to integrate our CICS application with another product, in this case, IBM’s message queueing product called MQSeries. The reason for doing this is to provide the head office of the KanDoIT company with a way of viewing the customer accounts from a workstation.

Important features of a message queuing product are:

The IBM MQSeries range of products provides application programming services that enable application programs to communicate with each other using messages and queues. This form of communication is referred to as commercial messaging. It provides assured, once-only message delivery. Using MQSeries means that you can separate application programs, so that the program sending a message can continue processing without having to wait for a reply from the receiving programs. If the receiver, or the communication channel to it, is temporarily unavailable, the message can be forwarded at a later time. MQSeries also provides mechanisms for the acknowledgment of messages received and processed.

One of the difficult areas of developing good commercial applications is to ensure that the interfaces between the products are as seamless as possible. To overcome this problem there are two bridge interfaces—MQSeries-CICS bridge and MQSeries-IMS bridge. Obviously we are only concerned with the MQSeries-CICS bridge in this part. There are two ways to use this bridge, the first, that we will be using, is the DPL function that accesses a user’s application directly while the other uses a user exit to emulate a 3270 terminal. This part contains the following chapters:

In addition to the usual software, we have used the following in this part: