This chapter was packed with concepts concerning reacting to events that happen in your monitored environment. We learned to describe conditions that should be reacted to as trigger expressions. Triggers themselves have useful functionality with dependencies, and we can make them depend on each other. We also explored several ways of reducing trigger flapping right in the trigger expression, including using functions such as min()
, max()
, and avg()
, as well as trigger hysteresis.
Among other trigger tricks, we looked at:
nodata()
function to detect missing datanodata()
function to make a trigger time outTrigger configuration has a lot of things that can both make life easier and introduce hard-to-spot problems. Hopefully, the coverage of the basics here will help you to leverage the former and avoid the latter.
With the trigger knowledge available to us, we will take the time in the next chapter to see where we can go after a trigger has fired. We will explore actions that will allow us to send emails or even run commands in response to a trigger firing.