pidproxy - Supervisor pidproxy Documentation

       This man page was created by Orestis Ioannou <orestis@oioannou.com> using the official documentation.

       2004-2015, Agendaless Consulting and Contributors

3.2.0                                           December 10, 2015                                    PIDPROXY(1)

daemontools
              A processcontrolsystembyD.J.Bernstein.

       runit  A processcontrolsystem.

       pidproxy - Supervisor pidproxy Documentation

       Supervisor  is  a client/server system that allows its users to monitor and control a number of processes
       on UNIX-like operating systems.

       It shares some of the same goals of programs like launchd, daemontools, and runit. Unlike some  of  these
       programs, it is not meant to be run as a substitute for init as "process id 1". Instead it is meant to be
       used  to  control  processes  related  to  a  project or a customer, and is meant to start like any other
       program at boot time.

pidproxyProgram
       Some processes (like mysqld) ignore signals sent to the actual process which is spawned  by  supervisord.
       Instead,  a  "special"  thread/process  is  created  by  these kinds of programs which is responsible for
       handling signals.  This is problematic because supervisord can only  kill  a  process  which  it  creates
       itself.   If  a  process  created by supervisord creates its own child processes, supervisord cannot kill
       them.

       Fortunately, these types of programs typically write a "pidfile" which contains  the  "special"  process'
       PID,  and  is  meant  to be read and used in order to kill the process.  As a workaround for this case, a
       special pidproxy program can handle startup of these kinds of processes.  The pidproxy program is a small
       shim that starts a process, and upon the receipt of a signal, sends the signal to the pid provided  in  a
       pidfile.  A sample configuration program entry for a pidproxy-enabled program is provided below.

          [program:mysql]
          command=/path/to/pidproxy /path/to/pidfile /path/to/mysqld_safe

       The  pidproxy  program  is  put  into  your configuration's $BINDIR when supervisor is installed (it is a
       "console script").