TP Environment and Design Considerations

Your choice of APPC/MVS callable services to use in a transaction program depends on the purpose of the application and design considerations such as portability, use of MVS-specific services, and transaction scheduling. Those factors and their implications are discussed in the following sections.

As you think about the design of cooperative applications that use APPC/MVS, consider the following questions:

Which part or parts of the application should run under MVS?
For the MVS part of the application, do you want the code to be portable to other systems? Do you want to include services that are unique to MVS?
When inbound requests for the program arrive, will the APPC/MVS transaction scheduler or another transaction scheduler initiate the program?
Assuming you use the APPC/MVS transaction scheduler, what schedule type (standard or multi-trans) should you design for? Considerations include:
- How often the program will be requested
- How long it will take the program to run
- How much resource allocation the program will require
- Whether you can provide security for multiple partners.
You will need to decide whether it would be more efficient for the transaction program to be initialized and ended for each conversation (standard scheduling), or to remain active between conversations and serve different partners in sequence (multi-trans scheduling).
Should the application use basic or mapped conversations? In other words, should it create logical records in a special format for transmitting data, or let APPC do the formatting?

The answers to these questions are fundamental to the design of an APPC/MVS TP. The following sections will help you find the answers.