Load Balancing Citrix StoreFront with Azure Load Balancer

Sometimes there is a requirement to Load Balance StoreFront using a method other than NetScaler. Although rare (in my experience!) this does occasionally happen when NetScaler is perhaps not being used for Remote Access –  in an internal only environment for example.

In this post I will explain how to Load Balance StoreFront using the native Azure Load Balancers. We start with a simple setup:

  • 1x Domain Controller
  • 2x Citrix StoreFront Servers – in an availability set called “EUS-StoreFront”
  • 1x Virtual Network (VNET)

All of the above is in the East US Azure Location.

We start by creating a new Azure Load Balancer. Note a few key settings here:

  • Type: Internal – this is because we are balancing traffic within our VNET (Internal Network only)
  • IP address – static… we don’t want the LB IP to change!

Once this is done – we can add the backend servers. We do this by targeting the Availability Set that the StoreFront Servers are in. For those familiar with NetScaler, this is similar to a Service Group:

Next – we need to configure some Health Probes. This allows us to determine the state of the StoreFront server and to confirm that the services we are load balancing are healthy and available. Note: at the current time Azure Load Balancer HTTP checks support relative paths only, so I have used /Citrix/CitrixWeb/monitor.txt – a simple text file (Static Content) I created to check that the Web Server is serving out content and thus working correctly. (https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/load-balancer/load-balancer-custom-probe-overview.md) I have configured by Health Probe as below:

Next – it’s time to create the Load Balancing Rule that will form the entry point for Load Balanced traffic. Note the Protocol (TCP), Ports (80 Frontend, and 80 Backend), Backend Pool (StoreFront Availability Set), Health Probe (our HTTP 80 monitor.txt check), Session Persistence (Client IP), and Idle Timeout (30 minutes is currently the maximum value):

We can then click OK and our Load Balancing Rule is created! Next I created a DNS A Record for StoreFront and pointed it at the Load Balancer IP. After this, I opened up a browser and typed in my newly created StoreFront DNS record. Bingo – we have a page!

To test that the Load Balancing was working. I shut down IIS on each server in turn, and then tested. Sure enough – even when only 1 out of 2 servers was running, the page stayed up and StoreFront was accessible.

This Load Balancer can be used for a variety of Web Applications, and is a simple way to Load Balance Azure based services as you require. Until next time… cheers!