Batch Processing

Enhanced Definition

The execution of programs without manual intervention, typically scheduled to run during off-peak hours to process large volumes of data. Batch jobs are defined using JCL and managed by the Job Entry Subsystem (JES). Batch processing on z/OS refers to the execution of a series of programs or jobs without manual intervention, typically scheduled to run at specific times or triggered by events. It involves the sequential processing of large volumes of data, often for tasks that do not require immediate user interaction. This method is fundamental to the operation of many core business functions on the mainframe.

Key Characteristics

- Non-interactive execution of predefined jobs
- Scheduled or event-triggered initiation
- High-volume data processing capability
- Resource-intensive operations during low-activity periods
- Automatic error handling and restart capabilities
Batch Job Components:
- Job: Complete unit of work with one or more steps
- Job Step: Individual program execution within a job
- JCL: Defines resources, programs, and data requirements
- Input/Output: Datasets and files processed by the job
- Condition Codes: Return codes indicating success or failure
Batch Processing Workflow:
1. Job Submission: Submit JCL to JES input queue 2. Job Scheduling: JES selects jobs based on class and priority 3. Resource Allocation: System allocates datasets and devices 4. Execution: Programs run sequentially through job steps 5. Output Management: Results written to SYSOUT or datasets 6. Job Completion: Cleanup and resource deallocation
- Payroll processing and financial calculations
- Report generation and distribution
- Data extract, transform, and load (ETL)
- Database backup and reorganization
- Data validation and cleansing
- File sorting and merging

Use Cases

- End-of-day transaction processing
- Monthly financial close procedures
- Nightly data warehouse updates
- Report generation for management
- Automated backup and maintenance tasks