Maximum Performance with WebSphere Application Server V5.1 on iSeries

Chapter 4. Tools for determining performance problems 99

 Job report

 Pool report

 Resource report

If you collect the trace data, you may also produce more detailed reports:

 Transaction report

 Lock report

 Batch job trace report

Advisor

Advisor is a semi-automatic tuner that provides an easy-to-use way to improve many of the

performance characteristics of your system. It can help you to define specific tuning values

and other parts of a processing environment to provide better performance for specific

processing conditions on your system.

Advisor analyzes performance data and then produces recommendations and conclusions to

help improve performance. It may recommend changes to basic system tuning values and list

conclusions about conditions that can cause performance problems.

You can choose to have the advisor change system tuning values as it recommends, or you

can decide to make only the changes you select. You can use Advisor’s conclusions to:

 Make changes to your system

 Guide further performance data collection

 Help you request performance reports that contain more information and explanations

Advisor may help you to improve system performance, but it does not identify or correct all

performance problems for you. Performance information analyzed by Advisor includes:

 Storage pool sizes

 Activity levels

 Disk and CPU utilization

 Communications utilizations and error rates

 I/O processor (IOP) utilization

 Unusual job activities: Exceptions or excessive use of system resources

 Interactive trace data (when available)

Advisor does not:

 Make any recommendations for changing specific application programs to improve their

performance

 Analyze non-interactive trace data

4.3.4 Using the system performance tools

If you suspect your system requires tuning changes, you need to investigate the items

outlined in this section.

CPU utilization

Java and WebSphere Application Server applications are typically CPU-intensive. Therefore,

you must first check CPU utilization. Use the following commands to determine if there are

too many jobs on the system or if some jobs are using a large percentage of processor time:

 WRKACTJOB (See the examples in 4.2.3, “WRKACTJOB command” on page 31.)

 WRKSYSACT