Java Troubleshooting Guide for HP-UX Systems

Figure 1-14 HPjmeter — Thread Histogram Screen
1.8 HPjtune
NOTE: The HPjtune product has reached end of life. HP has integrated HPjtune functionality
into HPjmeter 3.1 and recommends migrating to HPjmeter for the latest in bug fixes,
enhancements, and support.
1.9 hat
NOTE: Beginning with JDK 6.0, hat is replaced with jhat. For information on jhat, refer to
the jhat section in this document.
The hat tool is a third-party tool that can be used for heap analysis. It starts a Web server on a
binary-format heap dump file produced by one of the heap dump options such as
-XX:+HeapDumpOnCtrlBreak or -Xrunhprof:heap=dump,format=b.
The following example shows how to use hat. The first command generates a binary heap dump
file. The second command executes hat on the binary heap profile.
$ java -Xrunhprof:heap=dump,format=b MyApp
$ hat -port=7002 java.hprof
The hat tool sets up an http server on the specified port. It can then be accessed by bringing up
the default page in a Web browser, for example, http://<hostname.domain>:7002. If you
run hat on the same system as the browser, the server can be accessed by navigating to the URL
http://<hostname.domain>:7002.
For more information on hat, refer to the following website:
https://hat.dev.java.net
For invocation details, refer to:
36 Diagnostic and Monitoring Tools and Options