1 Introduction to Java Mission Control

1.1 Java Mission Control Client and Plug-Ins

The Java Mission Control Client is the application from which you connect to a JVM and start the tools that are included in JMC. On startup, the client shows the JVM Browser where you can choose a running JVM that you wish to monitor using one of the following methods:

• Connect a Management Console to the running JVM. Using the Management Console you can monitor the JVM and Java application while they are running. You can even change some of the JVM properties in run time through Managed Beans (MBeans).

• Create a recording of all behavior during application runtime.

The JMC tools communicate with the JVM using a JMX agent.

The plug-ins for Java Mission Control are:

• Management Console, for run-time monitoring and management of your JVM and Java application

• Java Flight Recorder, for always-available real time and historic performance monitoring and profiling.

1.2 Starting Java Mission Control Client

The JMC client executable file is located in the bin directory of the Java Development Kit (JDK) installation path (JAVA_HOME). If the JAVA_HOME/bin directory is in the PATH environment variable, you can start the JMC client by entering jmc at the coomand line prompt (shell). Otherwise, you have to specify the full path to the JMC executable:

• JAVA_HOME\bin\jmc.exe (Windows)

• JAVA_HOME/bin/jmc (Solaris, Linux, OS X)

Passing JVM Options To the JMC Launcher

JMC is a Java application, and the JMC client executable is a launcher for this application. JMC startup is controlled by options specified in the jmc.ini file, which is located in the JAVA_HOME/bin directory. Arguments to the -vmargs option in the jmc.ini file are options that are passed to the JVM running the JMC application. You can specify these options to control the way this JVM runs. If you do not want to modify the jmc.ini file, you can specify JVM options on the command line as arguments to the -vmargs option of the jmc command.

To start the JMC client with your own set of JVM options, overriding those specified in the jmc.ini file, run the following command (separate multiple arguments with spaces):

jmc -vmarg arguments

To start the JMC client with additional JVM options, appending them to those specified in the jmc.ini file, run the following command (separate multiple arguments with spaces):

jmc --launcher.appendVmargs -vmarg arguments

Using a Workspace Directory

If you want to copy your settings for the JMC client to another computer or another user, or use different predefined settings for different applications, add the -data command-line option and define a workspace directory when you start the JMC client:

jmc -data workspace-directory

Running JMC on OS X

On OS X, when you launch the JMC executable, the Terminal window opens. When you close the JMC client, the Terminal is left behind with the text [Process completed]. To avoid this, open the Terminal Preferences, then open the Settings tab, select the scheme you use, then select the Shell tab, and change the When the shell exits option to Close if the shell exited cleanly.

1.5 Giving Feedback to the Java Mission Control Development Team

If you have any suggestions about how to improve the Java Mission Control plug-ins or information on how it is most commonly used in your development environments, post a comment on the Java Mission Control forum. This information would contribute to our understanding on how to best further improve these tools in the future.

1.6 Abbreviations