IPT - Installation Performance Tool

Enhanced Definition

IPT, or Installation Performance Tool, refers to the systematic process and associated tools used to measure, analyze, and validate the performance of an IBM z/OS system after a new installation, upgrade, or significant configuration change. Its primary purpose is to ensure that the modified system configuration meets performance objectives and to identify any potential bottlenecks or regressions before the system goes into full production.

Key Characteristics

- System-Wide Focus: Concentrates on overall system performance metrics (CPU utilization, I/O rates, memory usage, paging activity) rather than individual application performance.
- Data Source Reliance: Heavily utilizes data collected by standard z/OS performance monitors like SMF (System Management Facilities) and RMF (Resource Measurement Facility).
- Pre-Production Validation: Typically performed in a test or staging environment to validate performance characteristics before deploying changes to the production environment.
- Bottleneck Identification: Designed to pinpoint performance bottlenecks introduced or exacerbated by the installation or configuration changes.
- Reporting and Analysis: Generates detailed reports, often with graphical representations, to visualize performance trends, resource consumption, and workload behavior.

Use Cases

- New z/OS Installation: Benchmarking the performance of a newly installed z/OS operating system to ensure optimal configuration and resource allocation.
- Hardware Upgrades: Assessing the performance impact of new processors, increased memory, faster I/O subsystems, or new storage devices.
- Software Version Upgrades: Evaluating the resource consumption and performance characteristics after upgrading major subsystems like DB2, CICS, IMS, or WebSphere.
- Significant Configuration Changes: Analyzing the effects of changes to WLM policies, I/O configurations (e.g., channel paths, control units), or large-scale dataset reorganizations.
- Performance Baseline Establishment: Creating a performance baseline for future comparisons after a major system change to track long-term performance trends.

Related Concepts

IPT relies fundamentally on data provided by SMF and RMF, which are the core z/OS facilities for collecting system and workload performance data. The analysis often involves evaluating the effectiveness of WLM (Workload Manager) policies under the new configuration. It is a critical step in the overall Capacity Planning process, providing essential data for future resource forecasting, and is typically performed by System Programmers or Performance Analysts.

Best Practices:

Establish a Baseline: Always capture comprehensive performance metrics *before* implementing any changes to provide a comparative baseline.
Use Representative Workloads: Conduct performance tests with workloads that accurately simulate typical production activity to ensure realistic results.
Focus on Key Metrics: Prioritize monitoring and analysis of KPIs (Key Performance Indicators) most relevant to the specific changes being implemented.
Iterative Testing: Implement changes incrementally and re-evaluate performance at each step to isolate the impact of individual modifications.
Document Everything: Meticulously record all configuration changes, test procedures, performance observations, and analysis results for future reference and auditing.