Plan for performance

Setting performance objectives for your iSeries™ server will allow you to have measurable performance benchmarks to compare your performance data. This topic will explain how to set those benchmarks and how to use them later.

Planning your system's performance requires you to set performance objectives, create benchmarks based on those objectives, and plan for your system's growth. This section guides you through the necessary steps in planning your system's performance.

When planning your system's performance, you will need to fully understand the business requirements your system is addressing and be able to translate those business needs into performance objectives. Keep in mind that as the business needs evolve, the performance objectives must also evolve.

Perhaps the best way to start is to estimate the maximum hourly and daily interactive transaction throughput required of your computer system during your peak business periods. After that, you can decide what average response time is acceptable to your local and remote workstations. You should think about how long your regular batch processes take, and how to schedule them so that they complete in time to achieve your business requirements.

You can then establish a base set of statistics, which should then be documented in a performance objective plan containing:

• The peak transactions per hour
• The peak transactions per day
• Acceptable average response time for local workstations
• Peak interactive transactions
• A list of the major scheduled batch jobs with times when they will be run and their expected duration
• A list of other unscheduled batch jobs that may be required

To plan for performance, complete the following tasks:

• Set system benchmarks
  Setting good system benchmarks will give you performance data for a properly tuned system. These performance benchmarks from both before and after system changes provide important information for both troubleshooting and planning.
• Determine when and how to expand your system
  As your business needs change, your system must also change. To prepare for any changes, you will want to model the current system and then see what would happen if the system, the configuration, or the workload were changed.
• Select a performance management strategy
  Different business needs require different performance management strategies. Here are three basic business models and their suggested performance management strategies.