Describe session handling in a web farm, how does it work and what are the limits ?
In ASP.NET there are three ways to manage session objects. One support the in-proc mechanism and other two's support the out-proc mechanism.
1) In-Proc (By Default)
2) SQL-Server (Out-proc) - Using SQL server or any other database for storing sessions regarding current logged in user.
3) State-Server (Out-Proc) - Using State Server, as one devoted server for managing sessions. State Server will run as service on web server having dotnet installed.