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Smarter Application Access to IMS Resources

IMS provides an improved runtime environment for online transaction processing

The IBM mainframe has celebrated 45 years of providing an upward- and downward-compatible runtime environment for customer applications. This fundamental principal was incorporated into the IMS architecture more than 40 years ago. IMS includes a transaction manager and a database manager that provide a runtime environment for online transaction processing.

The IMS Transaction Manager (TM) supports both an interactive terminal SNA-based network and a TCP/IP-based network. To provide network transparency and message integrity for the customer applications, IMS TM includes a queue manager. IMS customer application programs can use IMS Message Format Services (MFS) to build the I/O screen for the interactive terminal client. MFS parses the data to manage the I/O data streams for the application program. This provides device-independent application programming. Figure 1 is an example of an IMS MFS-managed interactive terminal screen.

Enhancing Web Enablement

Using device-independent programming enables the introduction of new client types that customers can leverage without requiring a modification to their IMS application investment. HTTP over the TCP/IP network established the foundation for the World Wide Web and the use of a Web browser to access IMS applications. The IMS MFS Web-Enablement solution supports the reuse of existing MFS-based IMS application business logic by Web browser clients without modifying the applications. Figure 2 shows how the MFS interactive terminal screen can be enhanced for Web enablement.

The World Wide Web leveraged the Internet to enable the development of application systems and to open the window of the desktop user to new opportunities. However, this Web 1.0 world didn’t have a complete set of standards, and standards became the next step of the Web’s evolution.

SOAP—which prior to version 1.2 stood for Simple Object Access Protocol—provides an XML-based network application protocol to establish a standard for exchanging structured information using HTTP. Web Services Description Language (WSDL) describes networked XML-based Web service interfaces and their associated interface methods. These two standards provided the framework that was used to build Web service applications that can interoperate using the intranet or Internet.

The IMS SOAP Gateway supports the SOAP and WSDL standards that enable IMS applications to perform as a Web service provider and consumer. The IMS SOAP Gateway server performs the conversion of SOAP messages, and the IMS Connect runtime supports the XML transformation to provide IMS application programs device independence. Figure 3 is an example of the WSDL generated by Rational Application Developer for System z to represent the IMS application program as a Web service provider.

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