If the service requester is WebSphere® MQ-enabled, you are required
to use the WebSphere MQ-CICS
Bridge to pass the request message to the DPL stub program DFHMADPL.
There are multiple ways to start the WebSphere MQ-CICS bridge. This section
explains how to start the CICS® bridge monitor program using WebSphere MQ
triggering.
To start the CICS bridge
monitor program using WebSphere MQ triggering, define the WebSphere MQ
request queue with TRIGGER, TRIGTYPE(FIRST) INITQ('initiation
queue') PROCESS('process') where:
- The initiation queue is the queue on which the CKTI
trigger monitor is listening.
- The PROCESS definition process must specify APPLTYPE(CICS)
APPLICID(CKBR). CKBR is the CICS bridge monitor transaction ID. The USERDATA parameter
in the PROCESS definition can specify AUTH and WAIT options
for the CICS bridge
monitor program.
The following steps describe how the runtime is invoked in asynchronous
mode. See
Figure 1 for an
illustration of this process.
- The service requester sends a request message to the request queue. This causes WebSphere MQ to send a trigger message to the specified
initiation queue.
- The WebSphere MQ
trigger monitor program starts the CICS bridge monitor task, that is part
of the WebSphere MQ-CICS
bridge.
- The CICS bridge
monitor browses the request queue. If a message has arrived,
the CICS bridge
monitor starts the CICS bridge link task, that is part of the WebSphere MQ-CICS
bridge.
- The CICS bridge
link task links to the DPL stub program, passing the request message in a
COMMAREA, and waits for control to be returned. The request message
that is passed to the stub program does not include the WebSphere MQ
header data. The DPL stub program defines and runs a BTS
process, passing the request message and waits for the adapter service processing
to complete.
- If a reply message is required, the DPL stub program passes it
to the CICS bridge
link task in the COMMAREA. The reply message contains the application
data and the message header.
- In synchronous processing, if the WebSphere MQ-CICS bridge header (MQCIH)
is not present in the request message, it will not appear in the reply message,
except in the case of an error.
- In asynchronous processing, the WebSphere MQ-CICS bridge header (MQCIH)
structure is always included in the reply message.
- The CICS bridge
link task responds to the service requester using an MQ PUT command
if the MQMD ReplyToQ and ReplyToQMgr are loaded.
Figure 1. Invoking the run time via WebSphere MQ-CICS
Bridge