ERE - Event Recording and Editing

Enhanced Definition

ERE (Event Recording and Editing) is a core component of CICS (Customer Information Control System) responsible for capturing and recording significant events that occur within a CICS region. It provides facilities to store these event records and utilities to edit, format, and report on the collected data, primarily for performance analysis, problem determination, and capacity planning. ERE (Event Recording and Editing) is an IBM z/OS utility program primarily used to process System Management Facilities (SMF) records. Its main purpose is to extract, filter, format, and report on system event data, providing crucial insights for performance analysis, problem determination, and capacity planning.

Key Characteristics

- CICS-Specific: ERE is an integral part of CICS, designed to monitor and record events generated by CICS transactions, programs, and the CICS system itself.
- Event Capture: It records various types of events, including transaction starts/ends, program executions, file I/O operations, terminal interactions, and system errors.
- Data Collection: Event data is typically written to SMF (System Management Facilities) records or dedicated CICS trace datasets, providing a historical log of system activity.
- Editing and Reporting: Provides utility programs (e.g., DFHERER) to process raw event data, format it into human-readable reports, and filter specific events for detailed analysis.
- Configurable Overhead: CICS administrators can configure the level of detail and types of events to be recorded, balancing the granularity of data with the performance overhead on the CICS region.
- Diagnostic and Performance Focus: The primary purpose of the collected data is to assist in diagnosing transaction abends, identifying performance bottlenecks, and understanding resource utilization trends.

Use Cases

- Performance Tuning: Analyzing transaction response times, CPU usage, and I/O activity to identify inefficient application code or resource contention within CICS.
- Problem Determination: Diagnosing CICS transaction abends, deadlocks, or system hangs by examining the sequence of events leading up to the failure.
- Capacity Planning: Gathering historical data on transaction volumes, peak loads, and resource consumption to forecast future hardware and software requirements for CICS environments.
- Application Development and Testing: Monitoring the behavior of new or modified CICS applications in test environments to validate performance and identify potential issues before production deployment.
- Auditing and Compliance: Tracking specific transaction activities or resource access for security audits or regulatory compliance purposes, especially when detailed event logs are required.

Related Concepts

ERE is tightly integrated with CICS, as it directly monitors and records events originating from CICS applications and the CICS system. The data collected by ERE is often stored within SMF (System Management Facilities) records, making it a crucial source of information for broader z/OS performance monitoring and reporting tools. It complements real-time monitoring solutions like OMEGAMON for CICS by providing historical data for in-depth, post-mortem analysis, offering a comprehensive view of CICS system behavior over time.

Best Practices:

Selective Recording: Configure ERE to record only the necessary events and at an appropriate level of detail to minimize the performance overhead on the CICS region. Avoid excessive tracing in production unless actively diagnosing a problem.
Regular Analysis: Periodically review ERE reports (or SMF data derived from ERE) to proactively identify performance trends, potential bottlenecks, or recurring issues before they impact users.
SMF Integration: Ensure CICS SMF recording is properly configured to capture ERE data, allowing for centralized storage, management, and analysis alongside other z/OS system metrics.
Automated Reporting: Utilize automation scripts or specialized performance management tools to generate and distribute ERE reports, especially for routine performance reviews and capacity planning.
Data Retention Policy: Establish a clear data retention policy for ERE data (or the SMF records containing it) to support historical analysis, auditing requirements, and long-term problem resolution.