Mac OS X Server: Processes

A process is a name for any running program that has its own memory space. Processes in Mac OS 8 include system software, application programs and background applications (such as FBC Indexing Scheduler, Control Strip, and Application Switcher). A background server process in Mac OS X Server is called a "daemon."
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In Mac OS X Server, several processes may be required to provide any given service. Starting an application also starts any other processes the application may need. If you know which processes are required for a certain service, you can check to make sure that they are running. A process that starts--or "spawns"--another process is called the parent process. A process that is started by a parent is called a "child" process. When a process is terminated intentionally, that is called "killing" the process. When a process stops working, it has "died." One step in troubleshooting a Mac OS X Server application is to determine if all its required processes are running. If a process is running but not responding, you may need to kill it.

Every process has a process identification number (PID) that is assigned according to order it was run. The first process that runs has a PID of 1. The second has a PID of 2 and so on. If a process dies or is killed, that PID is not reused. If the computer is restarted, the process count begins at 1 again.

You can use the ProcessViewer application to view and kill processes. This is similar to "force-quitting" an application in Mac OS 8. To do this, highlight a process in the process listing and choose "Quit Process" from the Process menu. If clicking the "Quit" button doesn't work, try the "Force Quit" button.

You open the ProcessViewer by choosing "Show All Processes" from the applications menu. It shows you the following information about each process:
  • Name - The name of the process (not the full path)
  • User - The name of the user that launched the process. System processes may show "root', "daemon", "www" or any user on your system.
  • Status - Can be running, stopped, waiting
  • % CPU - Shows what share of processor time a process is using. This is useful for performance analysis.
  • % Memory - Shows what share of RAM a process is taking. This is useful for monitoring RAM consumption.

More Info
  • Process ID- Shows the process ID, parent process ID, process group ID, Saved User ID and which terminal window the process was launched from (if applicable).
  • Statistics - Shows total CPU time, virtual memory size and resident memory size.
  • Path & Arguments - Shows which copy of a program was launched and the options (arguments) with which it was started.
Published Date: Feb 18, 2012