Logical Process Management and dbcc engine(offline)

If you are using logical process management to bind particular logins or applications to engine groups, use dbcc engine(offline) carefully.

If you take all engines for an engine group offline:

The login or application can run on any engine
An advisory message is sent to the connection logging in to the server

Since engine affinity is assigned when a client logs in, users who are already logged in are not migrated if the engines in the engine group are brought online again with dbcc engine("online").