Processing the outbound service request IBM-CICS

The figure shows the processing that occurs when a service requester running in a CICS TS V3.1 region sends a SOAP message to a service provider.

Outbound request processing

Outbound request processing

When the service requester issues the EXEC CICS INVOKE WEBSERVICE command, CICS uses the information found in the wsbind file that is associated with the specified WEBSERVICE definition to convert the language structure into an XML document. CICS then invokes the message handlers specified in the pipeline configuration file, and they convert the XML document into a SOAP message.

CICS sends the SOAP request message to the remote service provider via either HTTP or WebSphere MQ.

When the SOAP response message is received, CICS passes it back through the pipeline. The message handlers extract the SOAP body from the SOAP envelope, and the data mapping function converts the XML in the SOAP body into a language structure, which is passed to the application program in container DFHWS-DATA.

1. Local optimization

A special “local” optimization is possible when CICS is in the role of both service requester and service provider. In this case, CICS avoids the overhead of converting a language structure into an XML document by simply converting the EXEC CICS INVOKE WEBSERVICE command into an EXEC CICS LINK command.

When an EXEC CICS INVOKE WEBSERVICE command is used to invoke a CICS service provider application, the provider application name in the Web service binding file associated with the WEBSERVICE resource is used to enable the local optimization of the Web service request. If you use this optimization, the request is optimized to an EXEC CICS LINK command as in Figure.

Invoking a CICS Web service using local optimization

Invoking a CICS Web service using local optimization

The CICS service requester and service provider applications can be installed in the same CICS region or different regions. If they are in different regions, then an MRO or ISC connection must exist, which enables the LINK request to be shipped to the remote CICS region hosting the service provider application.

Note that this optimization has an effect on the behavior of the EXEC CICS INVOKE WEBSERVICE command when the Web service is not expected to send a response:

  • When the optimization is not in effect, control returns from the EXEC CICS INVOKE WEBSERVICE command as soon as the request message is sent.
  • When the optimization is in effect, control returns from the EXEC CICS INVOKE WEBSERVICE command only when the target program terminates.

When the Web service is expected to send a response, control returns from the command when the response is available.

Important: Invoking a CICS Web service using local optimization results in a significant performance benefit.


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