To demonstrate how nagios-herald can format alerts to be more legible and useful, see below for some example alerts without context (before nagios-herald) and with context (after nagios-herald).
This is a basic CPU alert informing the operator that something is wrong with a server's overall processor utilization.
The CPU check has been updated to inform the operator of which threshold has been exceeded and lists the top 5 processes by processor utilization and nagios-herald formatted the content to make it more legible.
Among most operators, disk space alerts probably garner the most disdain for their lack of utility and frequency of delivery.
It's easy to understand why disk space alerts are perceived to be useless given the following example.
Now, imagine how much more useful it would be if the check output the results of df and nagios-herald could use that information to provide context. In the example below, nagios-herald was used to add a stack bar to indicate which volume exceeded the threshold, add a Ganglia graph of disk utilization for the past 24 hours, highlight the relevant volume in the df output, and even inform the operator of the number of times in the last week that the alert fired.
Memory alerts that simply inform the operator that some threshold have been exceeded aren't very helpful.
The first thing most operators do is run top to understand what processes are running, sorted by memory usage. In the example below, the check was updated to output the top 5 processes by memory utilization and nagios-herald formatted the output for legibility.
