The XML Broker service is needed for communication between the web interface/StoreFront, and the data collector. Web Interface communicates using XML Broker to get information, such as application availability for a user, and available resources.

The XML Broker service is needed in a XenApp/XenDesktop environment, and can be deployed as a load-balanced service. Again, Citrix has made a custom monitor available, which we can use to monitor whether the XML Broker service is responding or not. To add the custom monitor, go to Load Balancing | Monitors, and click on ADD. Here, choose CITRIX-XML-SERVICE, and in the Special Parameters pane, enter an application name. The default application is Notepad. This monitor will open a connection to the service, and probe the XML Broker service to which it is bound. If the server responds as expected within the configured time period, the monitor marks the service as up. After this is added, we can start adding servers that have the XML service running under servers. Then, we add the XML service under services by choosing HTML as the protocol, and adding the port on which the XML service is running. Next, we need to create the load-balanced vServer, by choosing protocol HTTP and port 80, and binding the services to the vServer.

When we are finished with the configuration of the vServer, we can now use this IP when connecting to StoreFront or Web Interface. For example, if we want to use the vServer with Storefront, we can add the load-balanced server under Add Delivery Controllers | XenApp | Servers. Here, we can enter the IP address of the load-balanced XML service.