Task initiator

CKTI is a WebSphere MQ-supplied CICS transaction that starts a CICS transaction when a WebSphere 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, we 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. To start or stop a copy of CKTI, supply the name of the queue that this CKTI is to serve, or is serving. We cannot start more than one instance of CKTI against the same initiation queue from a single CICS subsystem.

At CICS system initialization or at connect time, we can define a default initiation queue. If you issue a STARTCKTI or a STOPCKTI command without specifying an initiation queue, these commands are automatically interpreted as referring to the default initiation queue.

Notes:

  1. If you are using version 4.1 of CICS, any transaction entries processed by CKTI, for example EXEC CICS START, are locked by the CKTI task until it terminates. Any attempt to CEDA INSTALL such entries after altering them will fail: CEDA rejects the install request because the transaction entry is being used by another task.

    In this situation, stop the CKTI task using the CICS adapter, and restart it after the CEDA install.

  2. This restriction also applies to intersystem connection (ISC) and multi-region operation (MRO) links. For example, if CKTI has started a remote transaction, a connection cannot be reinstalled until CKTI has been stopped.