NonStop Server for Java 7.0 Programmer's Reference

7 Application tuning and profiling
This chapter provides information about application tuning and profiling, and it includes the
following topics:
• “Profiling application performance” (page 86)
• “Tuning application performance” (page 89)
Profiling application performance
Application profiling and monitoring are supported through HPjmeter tool, which works in
combination with NSJ options, —Xeprof and —agentlib:hprof.
HPjmeter tool contains support for both 32–bit and 64–bit NSJ7.
The HPjmeter console is a GUI tool that runs on Java platforms that support GUI, such as HP-UX,
Linux, and Windows. It is used to perform the following profiling activities:
• “Monitoring live Java applications” (page 86).
• Analyzing garbage collection data.
• Analyzing profiling data.
Monitoring live Java applications
HPjmeter contains two components namely nodeagent and jvmagent. These components
obtain the data from Java and GC processes and consolidate them as a single process entity for
HPjmeter client. Only a 32–bit version of nodeagent is available.
Starting with HPjmeter 4.3, three versions of jvmagent are available. The following list describes
the available jvmagent versions. /usr/tandem/hpjmeter refers to the installation location of
HPjmeter:
• 32–bit jvmagent to be used with 32–bit NSJ7 applications. This is available at
$JMETER_HOME/lib/oss32.
• 64–bit jvmagent to be used with 64–bit NSJ7 applications. This is available at
$JMETER_HOME/lib/oss64.
• 32–bit jvmagent to be used with pre-NSJ7 applications. This is available at
$JMETER_HOME/lib/oss.
NOTE:
1. When distributed GC is enabled, HPjmeter interacts only with the Java processes and not GC
processes. The Java process provides all the necessary data that HPjmeter requires.
2. When HPjmeter is used to monitor Java process in real time, it only lists the Java process and
does not list the corresponding GC processes.
3. The threads in the GC process are not part of the thread count as shown by Threads Histogram
tab.
The Java application must be prepared for live mode of profiling by running HPjmeter agents.
The following procedure provides the set up for monitoring a live Java application:
1. Install the T0866H31 PAX file in the default installation directory: /usr/tandem/hpjmeter
2. Run the node agent:
a. export JMETER_HOME=/usr/tandem/hpjmeter/
b. $ JMETER_HOME/bin/nodeagent –port port_number
3. Launch the Java application using the HPjmeter JVM agent:
a. export _RLD_LIB_PATH=
86 Application tuning and profiling