Nagios Support Forum

Team,

I have a requirement where I need to monitor services running on two machines which act as master & slave.
Meaning, at a given point of time, both the servers (Master & Slave) are UP but services would be running on any one of these machines.
How can I define Nagios host and service definition for this kind off architecture?

Check out the check_cluster plugin.

There's also BPI which can be used to group services. You would set up both master and slave checks and group them into a BPI group. From there you can check the health of the group using check_bpi.php and send notifications based on the health.