Session State Management in Asp.Net

Session State Management in Asp.Net:-

Asp.Net session state management has built in  functionality that stores the data accordingly to the session.

Stateless Protocol:- Asp.net session state management  automatically erase the data if the client browser does not revisit the application with in a specified time.

Session State Modes:-

• InProcess
  
• State Server
• SQL Server

InProcess:-

In this mode Session, state is stored in the memory space of the Aspnet_wp.exe process. This is the default setting

Advantages:-

• It is default method.
• It is simplest method because no configurations are required as a part of development.
• It is fastest method.

Disadvantages:-

• Session information is lost if the Asp.net_wp.exe process is restarted.
• It is not suitable for web forms.

State Server:-

Session information is stored in a separate state server process. The worker processor will communicate  with the state server and retrieve the session information.

Steps to configure the State Server:-

• StateServer mode session data is stored in a different process so you must ensure that
  your objects are serializable.
• <machineKey> elements in Web.config should be identical across all servers. So this
  ensures that encryption format is same across all computers.
• IIS metabase (\LM\W3SVC\2) must be identical across all servers in that farm.

Advantages:-

Tolerance of  the worker process being recycled.

it is suitable for use on Web forms.

Disadvantages:-

• Slightly slower  and more resources demanding then In process, because there is no extra level communication is required between process.
• State information is stored in a single server.

SQL Server:-

Session information stored in a SQL Server data base. The worker process will communicate with the SQL Server to retrieve the session information.

Steps to configure the SQL Server:-

• SQLSERVER mode session data is stored in a different process so you must ensure that
  your objects are serializable.
• IIS metabase (\LM\W3SVC\2) must be identical across all servers in that farm.
• By default Session objects are stored in Tempdb, you can configure it store outside
• TempDB by running Microsoft provided SQL script.

Advantages:-

Tolerance of worker process crashes.

Suitable for Web forms.

Can be configured to work in a fail over clusters.

Disadvantages:-

Required SQL Server.

It is slower than both InProcess & State Server.

Complex to set up.