Hello SharePointer 🙂  !

Finally I have got room to summarize about the software load balancing implementation on SharePoint farm!As a SharePoint Administrator, load balancing is quite common job to configure in SharePoint farm. Let’s dig into it 😉

Why load balancing?

1. Single server doesn’t perform well enough due to high concurrent connections and IIS not being able to keep up with requests.
2. To separate some of the services across multiple servers like Excel Services, document conversion service or search.
3. To have resilience so that if one web server becomes unavailable the user connections will all be directed through the second web server.

As we know WFEs are the web servers in the SharePoint Farm and responsible for handling incoming web requests. Below diagram will help to understand how load is getting balanced:

Here are some quick steps to set up load balancing on a SharePoint farm.

1.       Installing the Network Load Balancing Feature on each WFE

1. Go to Server Manager and add the NLB feature.
2. Click Install.

2.       Adding a New Cluster – Load balanced servers need to be run within the context of a cluster. Here, cluster is collection of more than WFEs that acts under 1 IP address and hence cluster will looked up on as one machine. For easier administration, all WFEs must be identified as same IP and thus it’s being organized as one machine.

1. From the start menu, select Administrator Tools, and then click Network Load Balancing Manager.
2. Right-click Network Load Balancing Clusters and then select New Cluster.
3. Specify the first host in the cluster by typing the IP address of one of the WFE’s.
4. Click Connect
5. Click Next.
6. Leave the defaults, and then click next.

3.       Setting the cluster IP Address – The cluster needs a dedicated IP address as DNS must know the IP Address of the cluster to point.

1. On the Cluster IP Addresses box, click Add and type an available dedicated IP address and subnet mask
2. Click Next.

4.       Specifying Cluster Parameters  

1. Select cluster IP address from the drop down list.
2. Type your fully qualified domain name for the cluster.
3. Select the Multicast operation mode
4. Click Next.

5.       Specifying Port Rules – we need to add the port rules only for the ports we wish to accept on the WFEs.

1. On the default port rule, click Edit.
2. Deselect the “All” checkbox, and select Network Filtering Mode.
3. Click OK.
4. Click Finish.

When completed, the NLB Manager will start configuring process.

6.       Adding More Hosts  – The cluster is now ready for use, and you can add additional WFE’s if required as follows:

1. Right-click the cluster IP address.
2. Select Add Host To Cluster.
3. Type the IP address of the new WFE in the farm. Repeat the process for any additional WFE’s.

Now, SharePoint 2010 Farm is running with load-balanced WFE’s.Next, we need to test the clustered load balance and update the DNS entries for host names in order to point any SharePoint web application to the cluster IP address.

Let’s configure the DNS and test 🙂 !

1.       Configure DNS

1. Connect to DNS server.
2. Open DNS Manager from Administrative Tools.
3. Expand Server Name > Forward Lookup Zones >  Domain name
4. Double click on entry of your web application and change the existing IP Address as clustered IP Address and click OK.
5. Repeat same for other web application’s entries.

2.       Test DNS

1. In the command prompt type ping < web application name > and press enter.
2. You should get 4 replies from clustered IP address.

If it’s working that means, WFEs are getting responded from the cluster IP Address and DNS server correctly resolving the web application to Cluster IP Address.

Enjoy SharePoint Run ! 🙂