Web Interface 5.2 on Windows Server 2008 – configuring NLB Clustering

This guide to clustering Web Interface is intended as an extra to this article on configuring web interface correctly:

http://zenapp.blogspot.com/2010/04/installing-xenapp-6-part-4-web.html

 

1. Install Windows Server 2008 on two servers (or more – up to 32) and give them unique IP addresses on the same subnet. If you can, give them a second NIC and give it another IP, also on the same subnet.  If you don’t, you will have to use Multicast mode later, which might cause problems for your network. Enter a gateway for both network connections and check that they are both accessible on the network.  Yes, I know it will whinge.  For one of these connections go into its advanced networking settings and uncheck the checkbox for “Register this connection’s address in DNS”.  This is the network connection you should use to be a member of the cluster.
2. Install the same version of the Web Interface 5.2 on both servers, configuring them with the same settings.  Web Interface no longer supports centralised configuration so be sure that the configurations are identical.  Comparing the resulting config.xml files in the sites you create is a good idea, they should be the same.
3. Test both servers are able to function correctly.
4. On each server, open Server Manager and select Features.  Click Add Features and select Network Load Balancing, Next and Install.
5. On either server, click Start, Administrative Tools, Network Load Balancing Manager
6. Click Cluster > New.  Enter the name of the server you are on and click Connect.  You should see the Interface name and IP appear below.
7. Click Next and you should see something like the screen below.  Assuming you are happy with the IP it has chosen (this will not be the IP of the cluster but the IP this host uses to participate in the cluster), click Next
   
8. Enter a new IP for the Cluster to be known as.
9. Enter a name for the Cluster (you can create a more friendly DNS alias for the cluster later).
10. Choose the operational mode. If you use Unicast Mode (where the original MAC address of the servers’ NICs are replaced by that of the cluster) and you only have one NIC per server, the servers will not be able to see each other which might be a serious problem as they need to communicate to load balance effectively.  If you use multicast mode (where each servers’ NIC keeps its MAC address and gets a second new shared one for the cluster) you will probably have to make some network infrastructure changes to get other machines to see the cluster. So basically, get a second NIC in each server and choose Unicast.
    
11. Click Next and Finish to accept the rules.
12. Check your sites are available on the cluster IP address.
13. On the second server, open Network Load Balancing Manager.  Click Cluster > Connect to existing and enter the name of the first server (or the server name or IP)
14. Right click the cluster name and click Add Host To Cluster.  Add the second server and choose the network connection that is not set to register in DNS (assuming you had two).  Agree to everything else and the second server should then appear in the list and move quickly to “converging” status.  After a minute, refresh the list and it should go to Converged. 
15. The cluster should function correctly now without further changes, but I would also add some text to the web interface sites on both servers so you can tell where the content is coming from.  This will make troubleshooting easier later on.  Open the Citrix Web Interface Management tool on each server and right click each of the Web Sites.  Select Web Site Appearance.  Click Content, Add, choose your language code, click Next.  Select Footer Text, Next and enter the server name in the text box.  Click Finish, OK and OK.