The service requester

Stabilized feature: Service Flow Runtime and Service Flow Modeler capability in IBM Developer for z/OS 14.2.3 are stabilized. Consider exposing and orchestrating applications as API services by using z/OS Connect Enterprise Edition or CICS® web services, or by writing web applications in Java or Node.js. See also Stabilization notices and discontinued functions.

A service requester is the application that looks for and invokes or initiates an interaction with a service.

A browser driven by a person or a program without a user interface, for example a Web service, can play the role of a service requester. A service requester issues one or more queries to locate a service and to determine how to communicate with that service.

At run time, a service requester looks for and invokes an interaction with the service flow that has been deployed to the CICS Service Flow Runtime. The following table lists the supported interfaces that a service requester can use to pass in the message header and application data.

Service requester type Interface used
IBM® MQ-enabled application CICS-MQ bridge.

This interface serves as the interface between an IBM MQ-enabled service requester and CICS. The request message is passed in an IBM MQ message to an IBM MQ message queue.
Other applications

A CICS-supplied interface, such as EXEC CICS LINK, EXCI or ECI.

The IBM CICS Transaction Gateway (CTG) product.

The following applications are examples of service requester:
  • IBM MQ Integrator
  • IBM MQ Workflow
  • Web service
  • Any local or remote application that can initiate a CICS program

What the service requester is responsible for

The service requester is responsible for the following aspects of business transaction processing at run time:

  • Managing the overall business flow and compensation.
  • Managing business context, complex state, multiple requests and replies, and asynchronous request processing.
  • Overseeing the continuation of one logical request through multiple requests, if required.
  • Adhering to a published XML message format when creating valid XML request messages.
  • Performing data conversion if required. See Data conversion for information on how to perform data conversion.