"Supervising" syslog-ng in htop

Question

I was working at my server, when in htop I just noticed something unusual.

The syslog-ng process was listed as follows

supervising syslog-ng
    /sbin/syslog-ng

I don't know what it means. I tried to do man supervising but found nothing. supervising command doesn't exist too. Googling, I found a page about launchtool, but I can't find neither it or its man page in my system.

I'm curious

What does that executable/command/whatever do? Why today did I read that line in htop?

Thank you.

PS: I was unsure about posting this to SU or SF: even if it's a server-related question, it covers general Linux.

Answer 1

It's just a copy of syslog-ng that has changed its command-line arguments (argv[0]) to a more descriptive text.

The manual page of syslog-ng says:

OPTIONS

       [...]

       --process-mode 
           Sets how to run syslog-ng: in the foreground (mainly used for
           debugging), in the background as a daemon, or in safe-background
           mode. By default, syslog-ng runs in safe-background mode. This mode
           creates a supervisor process called supervising syslog-ng , that
           restarts syslog-ng if it crashes.

---

You can check with:

# pgrep -lf superv
1277 supervising syslog-ng
# readlink /proc/1277/exe
/usr/sbin/syslog-ng