I've had this issue with php-fpm from Macports which would fill up my log files rapidly and cause other mischief. The error message in question is:
ERROR: An another FPM instance seems to already listen on /opt/local/var/run/php56/php56-fpm.sock
I finally managed to fix it by simply forcing php-fpm to not run as a daemon by adding the
--nodaemonize switch to
Most likely this means that
daemondo keeps on spawning php-fpm instances although one already exists for some reason.
I think the default behavior for php-fpm is to listen on a TCP socket which might explain the issue, as I have changed it to listen on a Unix-socket instead.