See http://blog.pburkholder.com/2010/10/24/graphing-access-log-status-with-pnp4nagios/ http://blog.pburkholder.com/2010/12/03/graphing-access-log-status-with-pnp4nagios-part-two/ http://blog.pburkholder.com/2011/01/03/graphing-access-log-status-with-pnp4nagios-part-three/