Load balanced IIS Servers with ASP.NET InProc Session

Question

Has anyone configured IIS 6.0 loadbalancing on win 2003 servers with ASP.NET app using InProc Sessions. How can this be achieved?

Solution 1

If you are using the NLB clustering that ships as part of windows server 2003 then you are looking for the affinty setting. If you set this to "single affinty" then communication from one IP address will always route to the same server, thus allowing the client to get access to the InProc session state. There is some documentation on how to set it at http://technet.microsoft.com/en-us/library/bb734858.aspx

Solution 2

It could be achieved depending on how you are balancing.

A lot of balancers will allow you to nominate a cookie as their method for deciding where to direct stick sessions, but it's very dependent on the hardware/software balancer you're using. That's the only way it's going to work for you.

Solution 3

I can't say that I have ever load balanced an IIS 6 server with InProc sessions without using a load balancing device. If you can't use some kind of distributed cache, such as SQL Server or a more performant custom cache, you will probably need to set up some kind of "sticky session" routing in a load balancing device. This allows you to farm out your web sites, but for each user, for the duration of their session, they are repeatedly routed to the same particular server in the farm. This allows you to use InProc sessions, but at the relatively minor cost of not having perfectly ideal load balancing.

Note: You might get better answers for this kind of question over on StackOverflow's sister site: www.ServerFault.com.

Comments

[shreddd]

Do you have any tips about where I can read about "some kind of distrubuted cache"? =)

[shreddd]

danga.com/memcached or msdn.microsoft.com/en-us/data/cc655792.aspx

[Jeremy Davidson]

Not true, you can use InProc sessions provided that the load balancer uses cookies or source IP address to always send the same user to the same server. (However if a server falls over then the session data is lost.)