- Overview: What's a Mix?
- Real-World Low-Level Technology Stack Test Input and Mixes
- Testing and Tuning for Daily System Loads
- Testing and Tuning for Business Peaks
- Identifying Key Transactions and Business Processes
- Real-World Access Method Limitations
- Best Practices for Assembling Test Packages
- SAP Component and Other Cross-Application Test Mix Challenges
- Tools and Approaches
9.3 Testing and Tuning for Daily System Loads
Load testing the average daily expected workload is perhaps the most fundamentally overlooked type of performance testing I'm aware of. The companies that embrace performance testing and tuning tend to focus instead on high-water peak stress testing or saturation-level smoke testing, or spend their budget dollars tweaking and tuning the disk subsystem. Certainly, these other areas are critical, but the first question that comes to my mind is "How often do you see the loads associated with seasonal peaks?" followed by "How truly important is it to know precisely at what transaction load your system breaks?" when it has never even been tuned for the mundane daily workload processed 99% of the time.
Tuning for your anticipated daily transaction load should represent the starting point for SAP application-layer stress testing, and used, as depicted in Figure 9-2, as a launch pad for incremental load, stress, and smoke testing. Specifically, you should have a series of TUs or test packages that, when combined, can emulate the typical online and batch workload seen Monday through Friday, 9 a.m. through 5 p.m. In this way, subtle changes to your workload or configuration alike can be quickly simulated, providing the kind of rapid feedback necessary for supporting sound change control processes. And the tuning made possible will benefit you 99% of the time, huge by any measure, because your system is optimized for a relatively steady workload. Finally, understanding and capturing your daily system load pays big dividends when it comes time to perform a major upgrade, add or remove a significant component of the workload (acquisitions and divestitures), or simply build on the load in support of testing and tuning for various business peaks, covered next.
Figure 9-2 Use single-unit load testing as a springboard for daily load testing, peak stress testing, or high-water smoke testing.