"Alter Database" usually works. However, it may fail if there are un-committed distributed transactions. In this case the SPID is not showing under the database, and can't be terminated by...

As good as "ALTER DATABASE SET SINGLE_USER WITH ROLLBACK IMMEDIATE" can be, in some situations it can't be successful. You may get the below errors if there are uncommitted...

The format problem is resolved. The script in the original post should work now.

Sorry Guys... There was something wrong with the web editor. I have just resubmitted the script by removing all the ?. But until the script gets published again here, you...

I agree follow-on article(s) should be added.

As to the unexpected fail-over, it may indicate that there is a problem/situation in the cluster causing the is-alive check giving false alarm. Usually...