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Support for multisegment message processing programs in IMS Enterprise Suite SOAP Gateway single-service projects

This topic describes the ability of the Enterprise Service Tools perspective to enable IMS™ multi-segment Message Processing Programs (MPPs) as Web services in the bottom-up "Create New Service Interface" development scenario.

With certain restrictions, the language structure selection panels in the Web service wizard allow multiple language structures. As part of the page "IMS Message Layouts", two selection tabs are provided; the Request Message Layout tab and the Response Message Layout tab.

Use the "Request Language Structures" and "Response Language Structures" tabs on the "Language Structures" page to select the structures that describe the request and response interfaces to the IMS MPP. When language structures are selected on the language structure tabs, they are entered into corresponding tables on the "IMS Message Layouts" page.

After selecting the language structures, use the tabs on the "IMS Message Layouts" page to specify the layout of the request and response messages in detail. Indicate the order and count of each language structure in their respective messages by using the tables on the "Request Message Layout" and "Response Message Layout" tabs. The layouts specified in these tables indicate how the XML and binary messages are structured.

Limitations and Error Conditions

In general, multiple language structure selection and multi-segment support is supported only for IMS Enterprise Suite SOAP Gateway and IMS MPPs written in COBOL.

The following limitations apply when specifying the IMS message layouts:
  • While a language structure can occur more than once, the occurrences MUST be consecutive; they cannot be interleaved with occurrences of other language structures.
  • At most one language structure can occur a variable number of times (variable-count) and may only be followed by a language structure with a minimum and maximum count of one.
  • The total maximum size of the message layout, when represented in either XML or binary format cannot exceed 32MB when Enterprise COBOL V3R4 or later is used, or 16MB when Enterprise COBOL V3R3 or earlier is used.
The following limitations apply when selecting multiple language structures:
  1. Each language structure must begin with two 2-byte fields (LL and ZZ per IMS).
  2. Each language structure cannot exceed 32767 bytes (maximum size of an IMS message segment).
  3. At most 256 language structures can be selected for each of the request and response.
  4. Inter-language structure dependencies are not supported; for example, OCCURS DEPENDING ON (ODO) subjects in selected language structures cannot specify an ODO object declared outside of the structure.

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