Share session and sessionID across subdomain (MVC 3)

I tried desperately to find a solution for these two days, but all the tracks have not been conclusive.

I have a website with subdomains like A.mysite.com and B.mysite.com, And I need to share the session between all the subdomain and the domain.

I precise, the issue is not to have persistance across differents servers but in the same application keep the session alive between subdomains.

Any ideas will be really appreciated.

You can leverage the build in Session State Server facilities for this.

What this does is allow you to point the web sites to a sql server database in order to persist your session state as opposed to memory. All servers can utilize the same facility seamlessly to your a websites by using session just like you do normally.

There is only a web.config file change, and using aspnet_regsql.exe tool to set up the database facilities.

To set up the database with aspnet_regsql.exe the command line args are as followed;

-S Species the IP address or the name of SQL server in which you want to store the session state.

-U Specifies the user ID to be used when connecting to the SQL Server

-P Specifies the password to be used when connecting to the SQL Server

-E Indicates that you want to use integrated security when connecting to the SQL Server

-ssadd Adds support for the SQLServer mode session state

-ssremove Removes support for the SQLServer mode session state

-sstype Type of session state support. This option can be:

t for temporary storage

p for persistent storage

c for custom storage

-d The name of the custom database to use if -sstype switch is "c"

You would update your web.config file with the following syntax;

<sessionState 
        mode="SQLServer"
        sqlConnectionString="data source=MyDbServer;user id=<username>;password=<strongpassword>"
        cookieless="false" 
        timeout="20" 
/>

Here is a couple of good articles on how to accomplish this.

http://idunno.org/articles/277.aspx

http://support.microsoft.com/kb/317604

http://www.developer.com/net/asp/article.php/3595766/Storing-Session-State-in-a-SQL-Server-Database.htm

Since your main problem is assuring that the SessionID is the same in both subdomains, I think your in here is the global Application_PreRequestHandlerExecute event. You can check for the existence of the Session cookie from subdomain A, and set the ID in subdomain for B to the same ID. See post here; http://www.know24.net/blog/ASPNET+Session+State+Cookies+And+Subdomains.aspx