Multiple Drupal virtual hosts with their own syslog files
We have a shared hosting server that handles many Drupal sites within their own Apache virtual hosts. We had a need to track all available log messages for long periods of time, which the core watchdog module wouldn't allow us to do. So, we enabled the syslog module to write the messages to log files on the server.
To get all of the sites into their own log files we had to add the following code to /etc/rsyslog.d/drupal.conf