You are developing an ASP.NET MVC application. The application is deployed in a web farm and is accessed
by many users.
The application must handle web server failures gracefully. The servers in the farm must share the short-term
state information.
You need to persist the application state during the session.
What should you implement?

A.
ASP.NET session state

B.
A local database

C.
A state server

D.
Profile properties

Explanation:
ASP.NET session state service provides a somewhat slower service than the in-process variant as we need to
make calls to a remote server. All session data is stored in memory so shutting down the state machine will
wipe out all session data as well.
https://dotnetcodr.com/2013/07/01/web-farms-in-net-and-iis-part-5-session-state-management/