Common delay reasons beyond WLM’s scope of control include:
- Improperly tuned subsystems or workloads
- Improperly tuned Sysplex facilities such as coupling facility, structures, Cross System Coupling Facility (XCF), etc.
- Poorly tuned databases, applications, or database calls
- Poorly tuned z/OS systems or improper system setup
- Insufficient hardware capacity or poor I/O configuration.
The lesson here is to make sure that your systems and Sysplexes are tuned, and that your WLM controls take into account the time the workloads spend in states that are beyond WLM’s control and management. WLM goals and controls should always reflect the reality of the system, and it is still up to you to provide the workloads the best reality possible.
SCENARIO 6: BUSINESS PRIORITIES AND OBJECTIVES ARE CHANGING
In this scenario, all is running great in goal mode, but you’ve found out the business priorities and objectives are going to change. Perhaps workloads that used to be very important will no longer be as important. Maybe you want the work to achieve a different objective. Maybe an entirely brand-new key workload is being introduced.
When the business priorities change, do the WLM Service Definition and assigned goals need to be considered? The answer is yes. WLM goals and importance levels play a key role in the way WLM is going to manage the system resources and workloads. It is important for you and WLM to prioritize workloads relative to each other. WLM attempts to meet higher importance goals before trying to meet lower importance goals. Naturally, if the business priorities of the workload change, then importance levels and goals need to be revisited.
The most common examples I see for this scenario include:
- The business objectives change
- Merging of two companies/data centers
- Data center consolidation
- Consolidating workloads from multiple images to few images
- Introduction of new workload
- Server consolidation.
If your installation is planning any of these changes, then you need to consider revisiting and re-evaluating your WLM Service Definition, goals, and importance levels.
I recommend that you maintain an easily viewable version of your WLM Service Definition. In fact, you may want to convert your WLM Service Definition to HTML format and post this HTML page to some department Website so everyone on the performance team is familiar with the service definition.
If you want a simple way to convert your WLM Service Definition to HTML, feel free to visit my Website at www.epstrategies.com, select the button titled “WLM to HTML,” and you will be instructed on how to do this conversion. It is simple, easy, and the result will be very useful. If nothing else, you will see it is a much easier way of reading your WLM Service Definition than maneuvering through the WLM ISPF panels.
SCENARIO 7: INACCURACY OF REPORTED MEASUREMENTS