WAS Performance



Search Tips   |   Advanced Search



To identify application performance problems, WAS collects performance data and supplies interfaces that allow external applications to monitor the performance data. WAS also provides tools to display this data for analysis and suggests improvements.

IBM WAS collects data using PMI Request Metrics. by timing requests as they travel through WAS components such as Web Server, Web container, Enterprise bean container, and database. These data points are recorded in logs and can be written to Application Response Monitoring agents used by Tivoli or third party monitoring tools.


Performance Monitoring Infrastructure (PMI)

PMI uses a client-server architecture to collect performance data from WAS components.

The server collects PMI data consisting of counters such as servlet response time and data connection pool usage. The data points are then retrieved using a Web client, Java client or JMX client.

To display data, you can use the Tivoli Performance Viewer Java client.

To enable PMI Request Metrics, go to...

administrative console | Troubleshooting | PMI Request Metrics

...and set the following on the configuration tab...

Request Metrics Enable PMI Request Metrics.

ARM Generate Application Response Measurement data

Before enabling, install an appropriate ARM implementation on all WAS nodes.

Application Response Measurement (ARM) is an Open Group standard composed of a set of interfaces implemented by an agent that provides information on elapsed time for process hops.

WAS is not bundled with an ARM agent. Verify with your ARM agent provider that Request Metrics is supported by the ARM agent implementation. ARM support is dependent on Request Metrics support.

Trace Level Specifies how much trace data to accumulate for a given request.

Including one of the following:

NONE No trace;
HOPS Only accumulates on major process hops;
PERF_DEBUG Reserved for enabling additional information over hops, but is not as performance intensive as DEBUG;
DEBUG Reserved for full detailed trace. PERF_DEBUG and DEBUG provide the same level of performance tracing as the HOPS level.



Tuning involves adjusting application code, configurations, and system settings to improve performance.

To help administrators identify and maximize tuning opportunities, the product provides tools to suggest performance improvements.


Performance Advisors

IBM WAS includes two performance advisors to help tune systems for optimal performance. Both advisors use the PMI data to suggest configuration changes to ORB service thread pools, Web container thread pools, connection pool size, persisted session size and time, prepared statement cache size, and session cache size. The Runtime Performance Advisor runs in the appserver process, while the other advisor runs in the Tivoli Performance Viewer (TPV). The following summary chart outlines the difference between the two advisors. For more information, see the articles, Using the Runtime Performance Advisor and Using the Performance Advisor in Tivoli Performance Viewer.

  Runtime Performance Advisor Performance Advisor in Tivoli Performance Viewer (TPV)
Location of execution Application server TPV client
Location of tool Administrative console TPV
Output SystemOut.log file and WebSphere run-time messages in WebSphere status panel in the administrative console TPV graphical user interface (GUI)
Frequency of operation Every 10 seconds in background When you select refresh in TPV
Types of advice


See Also

PMI Request Metrics
PMIRM Filter collection
filterValues collection
PMI servlet
PMI client interface
PMI client package
PMI client with new data
Measuring data requests