Task initiator or trigger monitor (CKTI)

CKTI starts a CICS® transaction when an MQ trigger message is read; for example, when a message is put onto a specific queue.

When a message is put onto an application message queue, a trigger is generated if the trigger conditions are met. The queue manager then writes a message, containing user-defined data, known as a trigger message, to the initiation queue that has been specified for that message queue. In a CICS environment, you can set up an instance of CKTI to monitor an initiation queue and to retrieve the trigger messages from it as they arrive. CKTI starts another CICS transaction, specified using the DEFINE PROCESS command, which typically reads the message from the application message queue and then processes it. The process must be named on the application queue definition, not the initiation queue.

Each copy of CKTI services a single initiation queue. You can have more than one instance of CKTI monitoring an MQ initiation queue.

How to set up CKTI

An instance of CKTI can be set up in any of the following methods:

Using MQCONN and MQMONITOR resources

You can specify the name of the default initiation queue in the MQCONN resource definition for the CICS region. When you install the MQCONN resource definition, CICS dynamically creates and installs an MQMONITOR resource with the reserved name of DFHMQINI representing the default initiation queue. You can install more MQMONITOR resources to monitor other initiation queues.

An MQMONITOR resource allows the associated transaction that services an MQ queue to restart automatically when the connection to the MQ queue manager is established. You can use CEMT or CICS APIs to manually start or stop an MQMONITOR.

You can change the name of the default initiation queue by changing and reinstalling the MQCONN resource definition to create a new MQMONITOR resource definition. You can also name an alternative default initiation queue if you start the CICS-MQ connection manually.

Using a terminal from the CKQC transaction or a user-written program that links to DFHMQSSQ

The CKQC transaction gives you access to the control functions of the CICS-MQ adapter to initiate, manage, and view the connection between CICS and IBM® MQ. To start or stop an instance of CKTI, you can use the CKQC STARTCKTI or CKQC STOPCKTI command. You can start CKTI from a terminal from the CKQC transaction or from a CICS program that links to the adapter task initiation program, DFHMQSSQ.

To start or stop a copy of CKTI, you must supply the name of the queue that this CKTI is to serve or is now serving.

If you issue CKQC STARTCKTI or CKQC STOPCKTI commands without specifying an initiation queue, these commands are automatically interpreted as referring to the default initiation queue for the CICS region, which is specified in the INITQNAME attribute of the MQCONN resource, and the request will fail if the implicit MQMONITOR is already installed and started. When you install the MQCONN resource definition, CICS creates and installs an implicit MQMONITOR resource definition to represent the default initiation queue. You can change the name of the default initiation queue by changing and reinstalling the MQCONN resource definition to create a new implicit MQMONITOR resource definition. You can also name an alternative default initiation queue if you start the CICS-MQ connection manually.

CKQC does not control MQMONITOR resources.

CAUTION:

Using the CKQC transaction and MQMONITORs at the same time to manage instances of the CKTI transaction can lead to confusing statistics and STAT of an MQMONITOR because CKQC is not aware of MQMONITORs and because MQMONITORs are not aware of CKTI transactions managed by using CKQC.

Note: When CKQC STOPCKTI is issued, all transactions monitoring the initiation queue are stopped, including those associated with MQMONITORs.