Using internal metrics to debug potential issues

We'll re-send requests with slow responses again so that we get to the same point where we started this chapter.

 1  for i in {1..20}; do
 2      DELAY=$[ $RANDOM % 10000 ]
 3      curl "http://$GD5_ADDR/demo/hello?delay=$DELAY"
 4  done
 5
 6  open "http://$PROM_ADDR/alerts"

We sent twenty requests that will result in responses with random duration (up to ten seconds). Further on, we opened Prometheus' alerts screen.

A while later, the AppTooSlow alert should fire (remember to refresh your screen), and we have a (simulated) problem that needs to be solved. Before we start panicking and do something hasty, we'll try to find the cause of the issue.

Please click the expression of the AppTooSlow alert.

We are redirected to the graph screen with the pre-populated expression from the alert. Feel free...