We have Microsoft IIS configured in a failover cluster in our environment. We'd like to be able to monitor the service at the cluster level using the App Insight for IIS monitor. However, currently you can only assign the App Insight for IIS monitor to nodes. The operation will fail if you attempt to add it to a failover cluster. Because of this, attempting to monitor the service across the nodes in the cluster results in the monitor always showing as down since there is always a passive node in the cluster where the service aren't running.
This request and investigation has also been detailed in Case # 00265540