I have configured supervisord to track my unicorn server process. When I send USR2 process, this performs a rolling restart. After this operation the old unicorn master have restarted and then changed PID. This caused supervisor to lose track of the unicorn process considering it as EXITED. How can I have supervisord to follow the new unicorn process after this operation ? Unicorn has a PID file available, but I have not found an option in supervisord configuration for this. An other option would be to have supervisord to send itself the USR2 signal, but I don't know how to perform this and whether it will prevent my problem from occurring.