Enabling an IMS callout application as a web service consumer

To enable an IMS application as a web service consumer, you must modify your IMS application to issue callout requests, decide on your data transformation process, define an OTMA destination descriptor, generate the web service artifacts, and create a connection bundle.

SOAP Gateway supports both synchronous and asynchronous callout messages from IMS applications to external web services. For a synchronous callout request, the IMS application must wait in the dependent region for a response from the web service. The time to wait for the response is specified in the IMS call or in the OTMA destination descriptor that describes the routing of the messages.

Rational® Developer for System z® provides support for generating the web service artifacts to enable the IMS callout function in two approaches.
  • The meet-in-middle approach generates the required converter driver and correlator file from the web service WSDL file and your IMS callout application by creating the message mapping files for both the input and the output messages. This approach can be used for both synchronous and asynchronous callout scenarios, and for COBOL and PL/I applications.
  • The top-down approach generates the required converter driver, correlator file, and the COBOL copybook that contains data structures derived from the input and output messages of operations in the WSDL file. This approach is for synchronous callout only.
Ensure that you review the following topics before you proceed:
Tip: Any callout-related configuration and deployment changes that you make with the SOAP Gateway management utility take effect immediately.