Why Didn't I get Notified About This Error? - Global Verify
One of the most common problem users encounter is not getting notified about an error that they see in report after the fact, and the most common reason for this is the monitoring type selected for the monitor.
The most popular monitoring type selected by users is Global Verify. The monitoring configuration forces a remote test to verify an error before a notification for the error is triggered. For example; the test below failed from New York at 16:24:11 because the browser was unable to establish a TCP Connection. A retry from New York at 16:24:16 also failed. This triggers a Remote Verification test from a different location, Fremont in this case. The remote test passed with a 200 OK and as a result, we did not trigger a Notification for the error in New York and marked the test with an ST 70.
Now look at the example below. In this case we trigger an error from Boston at 4:03:10. There is no retry in this case, we go straight to the Remote Verification from Pittsburgh and that also fails at 4:03:15. Because the error was verified from the remote location, we notify in this case and mark the test as an ST 71.
In reports, both the errors in New York and Boston in these cases will count against availability. The remote verification simply determines whether or not a notification is triggered for the error.
Notifier rules follow this logic as well. That is, if your contact is configure to be notified only after 3 consecutive errors, 3 consecutive ST 71 errors would be required to meet the threshold.