Sending a SIGHUP signal

The probe can send a SIGHUP signal to the syslog daemon on startup. This forces the daemon to reread its configuration file.

To send a SIGHUP signal, the probe must be run as root. Use the following steps to ensure that the probe can be run safely without abusing root privileges:

  1. As root, change the owner of the probe binary using chown root nco_p_syslog.
  2. As root, enable the probe binary to run as setuid root, using chmod +s nco_p_syslog.
  3. Run the probe as a normal user.

This enables the probe to run as a normal user until it needs to perform the SIGHUP, at which point it becomes root, sends the signal to the daemon, and then relinquishes root privileges.

Note:

As running a probe as suid root causes environment variables to be ignored, this procedure only works if the IBM Tivoli Netcool/OMNIbus installation is on a local file system and installed in the default location.

There are potential problems when using the probe with suid root on AIX. Problems regarding library paths and events not being read properly by the probe have been noted on this platform. The workaround for this issue is to run the probe as a normal user and SIGHUP the syslog daemon by hand if a reread of the syslog configuration file is required.