Considerations for porting existing batch applications
By porting your existing batch applications,
more of your workloads can be managed by CICS®, reducing your dependence on the batch
window.
Before you begin
To port your existing batch application to the Batch programming
model, you will need to understand the way your existing batch application
works. For example:
- What resources does the application use? Typically this may include VSAM files, DB2 tables, or accessing CICS programs.
- What is the actual business logic of the program? A simple backup or does it update records? How complex are the updates?
- In what order are the files opened and closed and what keys are being used? This is especially important when you decide when the writes need to occur.
- How many records should be processed before taking a checkpoint? In traditional batch processing, the batch application can run alone, but with Modern Batch, you must consider contention for resources.
- Is each iteration of the loop functionally complete as if it were a transaction? For example, is the close inside the loop? How will this affect other transactions?
- Is the disposition of the data set compatible with access by multiple transactions? Look out for any job step with a disposition of KEEP.
About this task
Procedure
- Apply the business logic to The Batch programming model.
- Develop the new batch application. You can use the Sample applications as a guide or study the example applications provided in Developing the sample application with CICS Explorer SDK.
- Create the xJCL to create your Checkpoint algorithms and Results algorithm.
- Deploy the application to your system.
- Define and install CICS resources to access the data sources. For example the FILE resource enables access to a VSAM file.
- Submit the xJCL to the job scheduler.