# CICS Application-Initiated Request Reply

In the CICS application-initiated request reply scenario, a CICS application initiates an external request that expects a response by linking to a supplied CICS program that passes the COMAREA to Substation ES, and then waits for a response for a predefined time.

The following figure shows the CICS application-initiated request reply scenario:

Currently, this scenario causes an affinity between the initiating CICS application program and the Substation ES that handles the request.

Note: While this facility is a viable process for CICS Business programs to obtain data from a BusinessWorks progress, you must ensure that the BusinessWorks process delivers the response data in a timely manner 99.99% of the time. This is a synchronous process so the CICS transaction goes into a "wait" state until the response data is returned or a timeout. While in the "wait" state, all resources that the transaction acquired and/or locked remain in that state. Long response times from the BusinessWorks process can have major impact on your CICS environment.
Note: When setting up two or more Substation ES batch jobs to handle the CICS R/R request via SXCREQR or SXXREQR, you must do the following:

1. To each Trigger Definition that will handle the published message, the tibss-BES output property must be added.
2. To each message Consumer, you must copy the tibss-BES property from the input message to the response.
3. Each recipe that will handle the response message must have the tibss-BES property added as a required input property.
4. Each Substation ES must have an "intf-id" that matches the tibss-BES and points at the proper BES (CICS or IMS).

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