Example: planning a message channel on z/OS

The example illustrates the preparations needed to allow an application using queue manager QM1 to put messages on a queue at queue manager QM2. An application running on QM2 can retrieve these messages, and send responses to a reply queue on QM1.

The example illustrates the use of both TCP/IP and LU 6.2 connections. The example assumes that channels are to be triggered to start when the first message arrives on the transmission queue they are servicing.

Note: A message channel that uses TCP/IP can be pointed at an IBM® Aspera® faspio Gateway, which provides a fast TCP/IP tunnel that can significantly increase network throughput. See Defining an Aspera gateway connection on Linux® or Windows.

The payroll query messages are sent from QM1 to QM2 on a sender-receiver channel called QM1.TO.QM2, and the reply messages are sent back from QM2 to QM1 on another sender-receiver channel called QM2.TO.QM1. Both of these channels are triggered to start as soon as they have a message to send to the other queue manager.

The payroll query application puts a query message to the remote queue PAYROLL.QUERY defined on QM1. This remote queue definition resolves to the local queue PAYROLL on QM2. In addition, the payroll query application specifies that the reply to the query is sent to the local queue PAYROLL.REPLY on QM1. The payroll processing application gets messages from the local queue PAYROLL on QM2, and sends the replies to wherever they are required; in this case, local queue PAYROLL.REPLY on QM1.

Both queue managers are assumed to be running on z/OS. In the example definitions for TCP/IP, QM1 has a host address of 192.0.2.0 and is listening on port 1411, and QM2 has a host address of 192.0.2.1 and is listening on port 1412. In the definitions for LU 6.2, QM1 is listening on a symbolic luname called LUNAME1 and QM2 is listening on a symbolic luname called LUNAME2. The example assumes that these lunames are already defined on your z/OS system and available for use. To define them, see Example: setting up IBM MQ cross-platform communication on z/OS.

The example assumes that all the SYSTEM.COMMAND.* and SYSTEM.CHANNEL.* queues required to run DQM have been defined as shown in the supplied sample definitions, CSQ4INSG and CSQ4INSX.

The connection details are supplied in the CONNAME attribute of the sender channel definitions.

You can see a diagram of the arrangement in Figure 1.