JA - Job Accounting

Enhanced Definition

Job Accounting (JA) in z/OS refers to the systematic process of collecting and recording detailed information about the resources consumed by jobs, started tasks, and TSO users executing on the mainframe. Its primary purpose is to track system utilization for chargeback, performance analysis, capacity planning, and auditing.

Key Characteristics

- Comprehensive Data Collection: Gathers metrics on CPU time (TCB, SRB), I/O operations (EXCPs), memory usage, elapsed time, step execution time, and various other resource consumptions across the system.
- SMF Record Generation: All job accounting data is primarily recorded in System Management Facilities (SMF) records, specifically SMF Type 30 records for common resource usage, alongside other types for specific subsystems (e.g., DB2, CICS).
- Granularity: Data can be collected at the job, job step, or even individual program level, providing fine-grained insights into resource consumption patterns.
- Configurable: The types of resources tracked, the frequency of data collection, and the specific SMF record types generated can be configured via SMFPRMxx parmlib members and subsystem-specific parameters.
- Post-processing Required: Raw SMF data is stored in a proprietary binary format and requires specialized IBM utilities (like IFASMFDP) or third-party tools for extraction, formatting, and reporting.

Use Cases

- Chargeback and Billing: Enables organizations to accurately bill internal departments or external clients based on their actual consumption of mainframe resources, promoting cost awareness.
- Performance Analysis and Tuning: Provides critical data to identify resource-intensive jobs, bottlenecks, and areas for optimization within applications or system configurations.
- Capacity Planning: Historical accounting data helps predict future resource needs, informing decisions on hardware upgrades, software licensing, and system configuration changes to ensure adequate capacity.
- Auditing and Compliance: Offers a detailed audit trail of system activity, user actions, and resource usage, which is essential for security audits and regulatory compliance requirements.
- Problem Determination: Can help pinpoint which jobs or users were active and consuming significant resources during periods of degraded system performance or outages, aiding in root cause analysis.

Related Concepts

Job Accounting is intrinsically linked with System Management Facilities (SMF), which is the foundational component for collecting and storing this data. JES (Job Entry Subsystem) plays a crucial role as it manages job execution and interfaces with SMF to record job -related events and resource usage. The Workload Manager (WLM) often leverages accounting data to understand workload behavior and enforce service level objectives, while Resource Measurement Facility (RMF) provides real-time performance monitoring that complements SMF's historical accounting data. Jobs written in COBOL or controlled by JCL are the primary entities whose resource consumption is tracked by job accounting.

Best Practices:

Regular SMF Data Analysis: Implement a routine process for offloading, archiving, and analyzing SMF data to gain continuous insights into system usage, performance trends, and potential issues.
Optimize SMF Configuration: Carefully configure SMFPRMxx to collect the necessary data without incurring excessive overhead, balancing the level of detail with system performance impact.
Utilize Specialized Tools: Employ IBM utilities (e.g., IFASMFDP) or third-party SMF reporting and analysis tools to efficiently process, interpret, and visualize the complex accounting data.
Secure SMF Data: Ensure that SMF data sets and reports are properly secured using RACF or equivalent security managers to prevent unauthorized access, modification, or deletion, as they contain sensitive operational and billing information.
Align with Business Objectives: Tailor job accounting practices and reporting to align with organizational chargeback models, performance targets, and capacity planning strategies to maximize its business value.

The term "Jacket - Protective covering" is not a standard or recognized technical term within the IBM mainframe, z/OS, COBOL, JCL, CICS, DB2, or IMS ecosystem. It does not have a specific meaning or usage in this context.

Please provide a different term that is relevant to mainframe and z/OS technologies for which I can generate a glossary entry.