Suggested Services for a Single Address Space Transaction Manager

A single address space subsystem work manager performs functions similar to those shown in Figure 1. It goes through address space initialization and start-up routines. It receives a work request, processes the work request, receives another work request, and so on. At some point, it processes some address space clean-up and termination routines.

Figure 1. Sequence of functions in a single address space transaction manager.

If you have a single address space transaction manager, consider using the services shown in Figure 2 for the following functions in workload management:

• Associate work coming into the subsystem with a service class
• Have MVS™ match resources to the work to meet the service class goal
• Provide goal vs. actual information for reporting
• Provide response time information for work requests

The services shown in Figure 2 show when a single address space manager could invoke the appropriate workload management services. They are the minimum set of services a work manager can use to achieve the objectives listed above.

Figure 2. Work manager services for a single address space transaction manager.

You issue the IWM4CON service at address space initialization time. This connect service returns a token required by the IWM4CLSY and IWM4RPT services. When the address space receives a work request, it should issue the classify (IWM4CLSY) macro to associate arriving work with a service class. The subsystem work manager can issue IWM4CLSY in either problem state or supervisor state, in any PSW key. The PSW key, however, must be compatible with the key specified when IWM4CON was issued.

IWM4CLSY passed WLM information identifying the work request. This information includes the following:

• Subsystem environment and name (used on IWM4CON)
• Transaction/job name
• Transaction/job class
• User ID
• Accounting information
• LU name
• Network id

These are called work qualifiers. IWM4CLSY also supports a product-specific parameter, called the subsystem parameter. If none of the qualifier types listed above define your subsystem work manager's work requests, you can use the subsystem parameter.

The transaction manager should document which work qualifiers they use on the IWM4CLSY service, so that a customer knows how to define the classification rules defined in the workload management ISPF application. Also, because your transaction manager may not support all of the qualifier types, you should recommend that your customers customize the list of qualifiers for your subsystem type in the WLM ISPF application.

After receiving the work request and classifying it, the transaction manager then processes the work request. When it completes the request, it should issue IWM4RPT. The report service provides the arrival time and, optionally, completion information about the work request. Only normal completions are included in the response time information, so the information is not skewed by abnormal completions. The transaction manager should issue IWM4RPT only once per work request.

Then, at address space clean up and termination time, the transaction manager should issue a IWM4DIS, to disconnect from workload management services.