AD Replication Partner Count monitor. This monitor verifies that all of the incoming replication partners for this domain controller show the same operations masters.
Alerts raised indicate that this domain controller has an unusually high number of replication partners and is in danger of not being able to replicate in a timely fashion.
Review your directory replication design to decrease the number of replication partners for this domain controller.
This alert is commonly triggered by another domain controller failing, which causes the Knowledge Consistency Checker (KCC) to compute new optimal replication paths.
In this case, fix the failing domain controller and review your replication topology design to prevent future overloads in the event of a domain controller failure.