We have 5 exchange servers. 3 Database and 2 CAS.
One of our CAS vm's appeared to start having issues and began throwing this error in the event viewer.
The Service Control Manager tried to take a corrective action (Restart the service) after the unexpected termination of the Microsoft Exchange Health Manager service, but this action failed with the following error:
An instance of the service is already running.
All of our exchange boxes are:
Exchange Server 2013 Cumulative Update 3 (CU3) 15.0.775.38
With that said a lot of our citrix users were hit and miss. I am guessing CAS5 was not allowing and CAS4 was. Half the users could use outlook and have it load their profile etc.. the other half no, it would hand their citrix session.
This just randomly started happening yesterday Morning and a reboot fixed the server. That is not normal nor does it tell us what we can do to prevent this in the future.
While Looking online I see a lot of suggestions that point to the RPC service terminating but there are no logs in our event viewer that indicate that. Just the Service Control Manager and then the Health Manager.
If more detail needs to be provided please let me know, it is a fairly simple set up. 1 DAG, 5 servers, 2 of them CAS.