Added README and a flowchart

README.md

@@ -0,0 +1,40 @@
+# Nagios Failover #
+PHP script to help setting up Nagios with failover hosts. The whole idea of this
+script is to run in a cronjob on the failover host. When the remote, default,
+Nagios host goes down, the script will stop touching a "check file" to update 
+it's timestamp. If the remote Nagios is down for more than the predefined number 
+of seconds, the script activates the local Nagios notification. See the flow
+chart in this directory for more information on how the scripts works.
+
+## Usage ##
+Change the variables at the top of the script to suit your environment. Then
+place the script in a crontab (root for example, or someone with Nagios
+permissions) and let it run for example every fourth minute. If the $maxAge in
+the script is 1200 seconds (20 minutes) and the script is being run every fourth
+minute, then the check can fail 5 times (5x4=20) before activating the local
+Nagios notifications.
+
+## Misc thoughts ##
+Nowadays I only disable notifications on the failover hosts. I used to disable
+both host checks, service checks and notifications. Over the years this has
+turned out to generate a lot of false alarms. The false alarms are generate when
+the failover host for example disables it's checks after being active when a
+hosts being monitored where experiencing problems. The checks might than have
+stopped in a soft state with lets say 3/4. When the failover host is then once
+again activating it's checks, it's starts from this state (3/4) and if something
+then, for example, a flaky internet connection makes it fail one more time it
+has reached a hard state and an alarm is being sent.
+Another problem might be if a host or service was flapping the last time the
+failover Nagios was active and then had it's host and service checks disabled.
+The next time the failover Nagios is activated, the host/service which was
+flapping, is now still considered being in a flapping state, even tough this
+might have been two years ago, and thus preventing any alarms until the flapping 
+state goes away.
+For these reasons I now let the failover host run both host and service checks
+even when no failover is necessary.
+When the main Nagios then goes down, the failover Nagios has an up-to-date
+accurate state of all the hosts and services being monitored. 
+
+## Copyright ##
+This was script was written by Jack-Benny Persson and is released under GNU GPL
+version 2.

failover.php

@@ -22,7 +22,7 @@
     Simple script to turn on/off Nagios notification/checks etc for use with
     Nagios failover hosts.
     Default is to turn on/off notifications.
-    Version 0.2
+    Version 0.3
 */
 
 // Variables to set for your environment