Process supervision

Process supervision is a form of operating system service management in which some master process remains the parent of the service processes.

Benefits

Benefits^[1] compared to traditional process launchers and system boot mechanisms, like System V init, include:

• Ability to restart services which have failed
• The fact that it does not require the use of "pidfiles"
• Clean process state
• Reliable logging, because the master process can capture the stdout/stderr of the service process and route it to a log
• Faster (concurrent) and ability to start up and stop

Implementations

• daemontools
• runit
• Initng
• Monit
• Finit
• Supervisor: implementation in Python
• God: implementation in Ruby
• Eye: implementation in Ruby

References