Profiling Tools

You can use a profiler to perform remote profiling on the Enterprise Server to discover bottlenecks in server-side performance. This section describes how to configure these profilers for use with the Enterprise Server:

• The NetBeans Profiler

• The HPROF Profiler

• The JProbe Profiler

Information about comprehensive monitoring and management support in the Java 2 Platform, Standard Edition (J2SE platform) is available at http://java.sun.com/javase/6/docs/technotes/guides/management/index.html.

The NetBeans Profiler

For information on how to use the NetBeans profiler, see http://www.netbeans.org and http://blogs.sun.com/roller/page/bhavani?entry=analyzing_the_performance_of_java.

The HPROF Profiler

The Heap and CPU Profiling Agent (HPROF) is a simple profiler agent shipped with the Java 2 SDK. It is a dynamically linked library that interacts with the Java Virtual Machine Profiler Interface (JVMPI) and writes out profiling information either to a file or to a socket in ASCII or binary format.

HPROF can monitor CPU usage, heap allocation statistics, and contention profiles. In addition, it can also report complete heap dumps and states of all the monitors and threads in the Java virtual machine. For more details on the HPROF profiler, see the technical article at http://java.sun.com/developer/technicalArticles/Programming/HPROF.html.

After HPROF is enabled using the following instructions, its libraries are loaded into the server process.

To Use HPROF Profiling on UNIX

1. Use the Administration Console. Select the Enterprise Server component and the JVM Settings tab. Then select the Profiler tab.

2. Edit the following fields:

   • Profiler Name – hprof

   • Profiler Enabled – true

   • Classpath – (leave blank)

   • Native Library Path – (leave blank)

   • JVM Option – Select Add, type the HPROF JVM option in the Value field, then check its box. The syntax of the HPROF JVM option is as follows:

     -Xrunhprof[:help]|[:param=value,param2=value2, ...]

     Here is an example of params you can use:

     -Xrunhprof:file=log.txt,thread=y,depth=3

     The file parameter determines where the stack dump is written.

     Using help lists parameters that can be passed to HPROF. The output is as follows:

     Hprof usage: -Xrunhprof[:help]|[:<option>=<value>, ...]
     
     Option Name and Value   Description             Default
     ---------------------   -----------             -------
     heap=dump|sites|all     heap profiling          all
     cpu=samples|old         CPU usage               off
     format=a|b              ascii or binary output  a
     file=<file>             write data to file      java.hprof
                                    (.txt for ascii)
     net=<host>:<port>       send data over a socket write to file
     depth=<size>            stack trace depth       4
     cutoff=<value>          output cutoff point     0.0001
     lineno=y|n              line number in traces?  y
     thread=y|n              thread in traces?       n
     doe=y|n                 dump on exit?           y

     ---

     Note - Do not use help in the JVM Option field. This parameter prints text to the standard output and then exits.

     The help output refers to the parameters as options, but they are not the same thing as JVM options.

     ---

3. Restart the Enterprise Server.

   This writes an HPROF stack dump to the file you specified using the file HPROF parameter.

The JProbe Profiler

Information about JProbe from Sitraka is available at http://www.quest.com/jprobe/.

After JProbe is installed using the following instructions, its libraries are loaded into the server process.

To Enable Remote Profiling With JProbe

1. Install JProbe 3.0.1.1.

   For details, see the JProbe documentation.

2. Configure Enterprise Server using the Administration Console:

   1. Select the Enterprise Server component and the JVM Settings tab. Then select the Profiler tab.

   2. Edit the following fields before selecting Save and restarting the server:

      • Profiler Name – jprobe

      • Profiler Enabled – true

      • Classpath – (leave blank)

      • Native Library Path – JProbe-dir/profiler

      • JVM Option – For each of these options, select Add, type the option in the Value field, then check its box

        -Xbootclasspath/p:JProbe-dir/profiler/jpagent.jar

        -Xrunjprobeagent

        -Xnoclassgc

      ---

      Note - If any of the configuration options are missing or incorrect, the profiler might experience problems that affect the performance of the Enterprise Server.

      ---

      When the server starts up with this configuration, you can attach the profiler.

3. Set the following environment variable:

   JPROBE_ARGS_0=-jp_input=JPL-file-path

   See Step 6 for instructions on how to create the JPL file.

4. Start the server.

5. Launch the jpprofiler and attach to Remote Session. The default port is 4444.

6. Create the JPL file using the JProbe Launch Pad. Here are the required settings:

   1. Select Server Side for the type of application.

   2. On the Program tab, provide the following details:

      • Target Server – other-server

      • Server home Directory – as-install

      • Server class File – com.sun.enterprise.server.J2EERunner

      • Working Directory – as-install

      • Classpath – as-install/lib/appserv-rt.jar

      • Source File Path – source-code-dir (in case you want to get the line level details)

      • Server class arguments – (optional)

      • Main Package – com.sun.enterprise.server

      You must also set VM, Attach, and Coverage tabs appropriately. For further details, see the JProbe documentation. After you have created the JPL file, use this an input to JPROBE_ARGS_0.