Defining WebSphere MQ objects

Use one of the WebSphere MQ command input methods to define WebSphere MQ objects. Refer to Chapter 23, Monitoring and controlling channels on z/OS for information about defining objects.

Transmission queues and triggering channels

Define the following:

• A local queue with the usage of XMITQ for each sending message channel.
• Remote queue definitions.

  A remote queue object has three distinct uses, depending upon the way the name and content are specified:

  • Remote queue definition
  • Queue manager alias definition
  • Reply-to queue alias definition

  This is shown in Table 2.

Use the TRIGDATA field on the transmission queue to trigger the specified channel. For example:

      DEFINE QLOCAL(MYXMITQ) USAGE(XMITQ) TRIGGER(YES) +
             INITQ(SYSTEM.CHANNEL.INITQ) TRIGDATA(MYCHANNEL)
      DEFINE CHL(MYCHANNEL) CHLTYPE(SDR) TRPTYPE(TCP) +
             XMITQ(MYXMITQ) CONNAME('9.20.9.30(1555)')

The supplied sample CSQ4INYD gives additional examples of the necessary definitions.

Synchronization queue

DQM requires a queue for use with sequence numbers and logical units of work identifiers (LUWID). You must ensure that a queue is available with the name SYSTEM.CHANNEL.SYNCQ (see WebSphere MQ for z/OS Concepts and Planning Guide). This queue must be available otherwise the channel initiator cannot start.

Make sure that you define this queue using INDXTYPE(MSGID). This will improve the speed at which they can be accessed.

Channel command queues

You need to ensure that a channel command queue exists for your system with the name SYSTEM.CHANNEL.INITQ.

If the channel initiator detects a problem with the SYSTEM.CHANNEL.INITQ, it will be unable to continue normally until the problem is corrected. The problem could be one of the following:

• The queue is full
• The queue is not enabled for put
• The page set that the queue is on is full
• The channel initiator does not have the correct security authorization to the queue

If the definition of the queue is changed to GET(DISABLED) while the channel initiator is running, it will not be able to get messages from the queue, and will terminate.

Starting the channel initiator

Triggering is implemented using the channel initiator. On WebSphere MQ for z/OS, this is strarted with the MQSC command START CHINIT PARM(xparm) where xparm is your channel initiator parameter module.

Stopping the channel initiator

The channel initiator is stopped automatically when you stop the queue manager. If you need to stop the channel initiator but not the queue manager, you can use the MQSC command STOP CHINIT.