Network Deployment (Distributed operating systems), v8.0 > Tune performance > Obtaining advice from the advisors > Why to use the performance advisors > Performance advisor types and purposes
Performance and Diagnostic Advisor
Use this topic to understand the functions of the Performance and Diagnostic Advisor.
The Performance and Diagnostic Advisor provides advice to help tune systems for optimal performance and is configured using the console or wsadmin.sh. Running in the JVM of the application server, the Performance and Diagnostic Advisor periodically checks for inefficient settings and issues recommendations as standard product warning messages. These recommendations are displayed both as warnings in the administrative console under Runtime Messages in the WAS Status panel and as text in the application server SystemOut.log file. Enabling the Performance and Diagnostic Advisor has minimal system performance impact.
With WAS v8 you can configure the server to use the HPEL log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files or native z/OS logging facilities. If you are using HPEL, you can access all of your log and trace information using $PROFILE/bin/LogViewer.sh.
The Performance and Diagnostic Advisor provides performance advice and diagnostic advice to help tune systems for optimal performance, and also to help understand the health of the system. It is configured using the console or wsadmin.sh. Running in the JVM of the application server, the Performance and Diagnostic Advisor periodically checks for inefficient settings and issues recommendations as standard product warning messages. These recommendations are displayed as warnings in the administrative console under Runtime Messages in the WAS Status panel, as text in the application server SystemOut.log file, and as Java Management Extensions (JMX) notifications. Enabling the Performance and Diagnostic Advisor has minimal system performance impact.
From WAS Version 6.02, you can use the Performance and Diagnostic Advisor to enable the lightweight memory leak detection, which is designed to provide early detection of memory problems in test and production environments.
The advice that the Performance and Diagnostic Advisor gives is all on the server level. The only difference when running in a WAS ND environment is that you might receive contradictory advice on resources that are declared at the node or cell level and used at the server level.
For example, two sets of advice are given if a data source is declared at the node level to have a connection pool size of {10,50} and is used by two servers (server1 and server2). If server1 uses only two connections and server2 uses all fifty connections during peak load, the optimal connection pool size is different for the two servers. Therefore, the Performance and Diagnostic Advisor gives two sets of advice (one for server1 and another for server2). The data source is declared at the node level and make your decisions appropriately by setting one size that works for both, or by declaring two different data sources for each server with the appropriate level.
Read the using the performance and diagnostic advisor information for startup and configuration steps.
Related
Diagnostic alerts
Performance advisor types and purposes
Lightweight memory leak detection
Use HPEL to troubleshoot applications
Use the Performance and Diagnostic Advisor
Enable the Runtime Performance Advisor tool using scripting