Offline Profiling

   

  JProfiler's offline profiling capability allows you to run profiling sessions from the command line without the need for starting JProfiler's GUI front end. Offline profiling makes sense if you want to
  • perform profiling runs from a scripted environment (e.g. an ant build file)
  • save snapshots on a regular basis for QA work
  • profile server components on remote machines via slow network connections

Performing an offline profiling run for your application is analogous to remote profiling with special library parameters passed to the profiling agent VM parameter -Xrunjprofiler for Java <=1.4.2 (JVMPI) or -agentpath:[path to jprofilerti library] for Java >=1.5.0 (JVMTI):

  • offline switch
    Passing offline as a library parameter enables offline profiling. In this case, a connection with JProfiler's GUI is not possible.
  • session ID
    In order for JProfiler to set the correct profiling settings, a corresponding session has to be configured in JProfiler's GUI front end. The ID of that session has to passed as a library parameter: id=nnnn. Your settings in the profiling settings dialog are used for offline profiling. The session ID can be seen in the top right corner of the application settings dialog.
  • config file location (optional)
    The config file that is read for extracting the session with the specified ID has to be passed via config={path to config.xml}. The config file is located in the .jprofiler7 directory in your user home directory (on Windows, the user home directory is typically c:\Documents and Settings\$USER). If you leave out this parameter, JProfiler will try to detect the config file location automatically.

A summary of all library parameters is available in the remote session invocation table.

If you profile on a machine where JProfiler is not installed, you will need to transfer the contents of the bin/{your platform} directory as well as the JAR file bin/agent.jar and the config file {User home directory}/.jprofiler7/config.xml.

Example:

A typical invocation for offline profiling with Java >=1.5 (JVMTI) will look like this: 

        java "-agentpath:C:\Program Files\jprofiler7\bin\windows\jprofilerti.dll=offline,id=109,config=C:\Users\bob\.jprofiler7\config.xml"
        "-Xbootclasspath/a:C:\Program Files\jprofiler7\bin\agent.jar"
        -classpath myapp.jar com.mycorp.MyApp

Please study the remote session invocation table to generate the correct invocation for your JVM. Also, please don't forget that the platform-specific native library path has to be modified, just like for remote profiling.

  If the generated snapshots have heap dumps in them, you can use the jpanalyze executable to prepare the heap dump analysis in advance. Opening the snapshot in the JProfiler GUI will then be very fast. The executable is named jpanalyze.exe on Windows and jpanalyze on Unix-based operating systems and is located in the bin directory of a JProfiler installation. If you execute it with the -help option, you will get help on its usage: 
  Usage: jpanalyze [options] "snapshot file" ["snapshot file" ...]

  where "snapshot file" is a snapshot file with a .jps, .hprof, or .dat extension
        [options] is a list of options in the format -option=value

  Options:
      -format=dir|tar|tgz
          The format in which the analysis data should be stored. Defaults to
          dir.
      -removeUnreferenced=true|false
          If unreferenced or weakly referenced objects should be removed.
      -retained=true|false
          Calculate retained sizes (biggest objects). removeUnreferenced will be
          set to true.

The removeUnreferenced and the retained command line options correspond to the options in the heap walker options dialog.

  If you start your application from an ant build file, you can use the ant task to easily profile your application in offline mode.
  If you already have a launched "Application" session defined, you can generate a start script for offline profiling with the local to offline conversion wizard on the "Convert" tab of the start center or by selecting Session->Conversion wizards->Convert application session to offline from the main menu.
  To control CPU profiling, triggering of heap dumps and saving of snapshots during an offline profiling session, you can use the
  • Profiling API
    JProfiler's profiling API allows you to control the profiling agent from your own code. An example on how to use the offline profiling API is available in the $JPROFILER_HOME/api/samples/offline directory.
  • Triggers

    With triggers, you can define all profiling actions in the JProfiler GUI.

  • JProfiler MBean

    On Java 1.5+, the profiling agent registers an MBean that gives access to all profiling actions. MBeans are configurable in jconsole:

    Most methods of the com.jprofiler.api.agent.Controller are reflected in the MBean. For documentation of the MBean operations, please see the javadoc of com.jprofiler.api.agent.mbean.RemoteControllerMBean.

    The MBean may also be accessible via configuration facilities of an application server or other tools.

  • Command line controller

    With Java 1.5+, you can use the command line controller tool to interactively record profiling data and save snapshots in a convenient way without having to use a separate MBean viewer.

  If wish to analyze profiling information at run-time, you can use the profiling platform that is part of JProfiler. Please see the javadoc in $JPROFILER_HOME/api/javadoc and the sample in $JPROFILER_HOME/api/samples/platform for more information.