ASP.NET and Load balancing.
In one of our project the site usage of site was very heavy and we need to migrate it to load balancing server. I have never configured the sites in the load balancing server but it was quite interspersing experience Here are the some points which we need to take care while we move asp.net sites into the load balancing environments. So first we will see what is load balancing.
Following is a load balancing definition from the Google.
In computer networking, load balancing is a technique to distribute workload evenly across two or more computers, network links, CPUs, hard drives, or other resources, in order to get optimal resource utilization, maximize throughput, minimize response time, and avoid overload.
Following are the points which you need to take care when you are deploying your asp.net sites into load balancing server environments.
Machine Key Should be same for both servers: View state and session both are depends on the machine key. If you machine key is not same then you will have problems related to session and view state you may loose your session and view state in between request during post backs. If machine key will not be same then its possible that you can get strange result in Ajax requests. There is a machine key section in web.config where you can specify machine key.
<machineKey validationKey='C44B8B7C521CB5BC7E602BAE6118AA44CD690C7304817129DA27C17E800132A1BD946C6D9AD12F0A5B342840C7D130564195428160B7466146938CA9E3A62686' decryptionKey='0E9DF2DA7F210B84087690FF0BF25C905182AD81E16A5FA9' validation='SHA1'/>
Following is a good link to learn how you can configure sessions state in asp.net application.
And here is a good link to configure session on SQL Server.
<sessionState mode="SQLServer" StateConnectionString="tcpip=127.0.0.1:42424" SqlConnectionString = "data source=SERVERNAME; user id=sa; password=sa" cookieless="false" timeout="20" />
<system.web> <pages enableViewStateMac="false" /> </system.web>
File Replication:File Replication is also an important features of load balancing you should have replication enabled on the folders of web application so if you upload anything on one server it should replicated to other sites. Following is good link to understand file replication.
Sticky Sessions: In some scenario Sticky session is very useful. In one page our application we have used extensive Ajax and we need that for each request and partial post back it should stay on one server till request completes.To achieve that we can used sticky session. Following are some good links to know about sticky sessions.
Hope this will help you on deploying your asp.net on load balancing sites. Following are some good links for understanding load balancing in more details