Galaxy Communicator Tutorial:

How to Use the Process Monitor

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The process monitor is a tool which allows the user to control and monitor system processes in a variety of configurations. This tools is used extensively in the tutorial and in the examples in the Galaxy Communicator distribution. In this lesson, we learn about the various parts of the process monitor and how to use them.

Once you feel comfortable with the process monitor, if you want to know more, you can consult the process monitor reference.

Starting the process monitor

There are a couple different ways to start the process monitor, but we'll be starting it with a file which describes the configuration of processes that it will run. The process monitor executable can be found at $GC_HOME/contrib/MITRE/tools/bin/process_monitor. Let's start it up to run a couple of simple Unix applications.
[Process monitor exercise 1]


% process_monitor $GC_HOME/tutorial/process_monitor/dir.config 1 &


C:\> python %PM_DIR%\ %GC_HOME%\tutorial\process_monitor\dir.config 3

(If the shell can't find the process monitor application, make sure you've configured your environment correctly.) You'll get a window which looks like this (on Unix; it will look a little different on Windows)::

The menu bar

The process monitor contains a menu bar, which controls the overall configuration of the process monitor and the collection of processes.

The File menu

The File menu contains the Quit command, which shuts down all the processes and exits the process monitor.

The Process Control menu

The Process Control menu contains three commands:

The Configuration menu

The Configuration menu allows you to choose between two different configurations:

The Process Set menu

If the configuration file you're using has more than one set of processes it can run, the Process Set menu will switch between different sets of processes. When you switch between process sets, the current process set (if there is one) will be shut down.

The process panes

The process monitor presents each process as four panes: Whether or not all these panes are visible depends on the Hide/Show button. In the example here, there are two processes, one which has all four panes visible, and one which has only the command bar.


Press the button marked "Hide" on the command bar titled "Current directory". See how the lower three panes for the process vanish. Like the command bar titled "Directory contents", the run status now appears on the command bar on the far right, and this button now reads "Show". Press it again to restore the configuration.


Press the button marked "Start". The process monitor will now run a command which prints the current working directory, and you'll see something like the following output in the scrollable output history:
[Scrollable output pane]


[exec pwd 2>&1]


[cmd.exe /c chdir]

Note the row of equals signs ("="). This indicates that the process has halted. You may also have noticed that for the instant the process is running, this button reads "Stop". While the button reads "Stop", you can press it to stop the process.

Keep alive/Let die

Press the button marked "Keep alive". The process will now be automatically restarted if it dies of its own accord. The button now reads "Let die". Press "Start" and notice how the command is called over and over. Press "Stop" to halt this sequence, and "Let die" to disable automatic restart.


Press the button marked "Clear". The scrollable output history is cleared and the command to be executed is rewritten to the output pane.

Pause output/Resume output

This final toggle button pauses and resumes the output. Press "Keep alive" again, and then "Start". As the process is running over and over, press "Pause output", and note that nothing is now being added to the scrollable output pane. The button now reads "Resume output". Press "Resume output", then "Stop", then "Let die".

Using the menu bar

Press "Show" on the command bar titled "Directory contents". Select "Process Control -> Restart all". Both processes run and terminate. Select "Process Control -> Clear all" to clear all the scrollable output panes.

Next, we'll switch configurations. Select "Configuration -> Compressed configuration -> One button row". Now the process monitor displays a single output history, command line and control bar, with a row of buttons directly below the menu bar to select the displayed process. Try switching between the two processes, and start, stop and clear the processes to convince yourself that the process displayed in the pane corresponds to the selected process in the button row.

The "Detach this pane" button at the bottom allows you to view a given process in its own window with its own set of panes. Press this button. The button corresponding to the current process disappears from the button row, and the new window which appears has a no menu bar and a button at the bottom which says "Reattach this pane". When the separate window is reattached, the corresponding button is re-added to the button row on the main window.

Finally, let's switch process sets. Select "Process Set -> Environment settings". Now the process monitor displays a single process, different from the others. Start this process. Now use the "Process Set" menu to switch between the two process sets. Notice that each process set is in the state you left it in.

Once you're done exploring the process monitor, select "File -> Quit" to exit.

Next: A sample end-to-end system: MITRE's toy travel demo

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Last updated August 6, 2002