Linux Interview Questions: - Which daemon is responsible for tracking events on Linux system?
syslogd is responsible for tracking system information and save it to the desired log files. It provides two system utilities which provide system logging and kernel message trapping.
Internet and UNIX domain sockets support enable this utility package to support both local and remote logging.
Every logged message contains at least a time and a hostname field, normally a program name field, too. So to track these information this daemon is used. syslogd mainly reacts to the set of signals given by the user. These are the signals given to syslogd:
- SIGHUP: This lets syslogd perform a re-initialization. All open files are closed, the configuration file (default is /etc/syslog.conf) will be reread and the syslog facility is started again.
- SIGTERM: The syslogd will die.
- SIGINT, SIGQUIT: If debugging is enabled these are ignored, otherwise syslogd will die.
- SIGUSR1: Switch debugging on/off. This option can only be used if syslogd is started with the - d debug option.
- SIGCHLD: Wait for Childs if some were born, because of waiting messages.