As per current custom event alerts the threshold is set to raise an alert if availability falls below 100% for 1 minute out 5 minutes period. However, in the case the queue is down the current scenario no data is treated with the problem closed. Creating a scenario where the original queue down problem gets closed after every 5 minutes and reopens when again when queue plugin tries to look up data in a couple of hours. When such auto-closing problems are linked with ServiceNow integration, they end up creating multiple tickets on the user end.
In short, if there is no data coming for IBM MQ, the problem raised for the first time should remain open and duplicates should not be raised. And when the data starts coming the problem is resolved.
When the queue manager in IBM MQ goes down, there will be no data to fetch. So no data means zero availability. In this case, at the moment Dynatrace opens and resolves the problem every 2 hours because there is no data and Dynatrace is not sure of the problem. If there is no data coming for 2 hours or more then please consider that there is zero availability and keep the very first problem raised open and resolve it once data starts coming.