In XenApp 6.5 we have 2 roles for the servers, a Worker role (session host only) and a Controller role. The default role for a XenApp server is a Controller role. The controller server is responsible for farm management tasks and the task of the Worker role is to host user sessions.

A farm requires at least one Controller, which handles the XML broker and Zone Data Collector roles. A Worker cannot perform the role of a Data Collector and cannot participate in elections.

There are two methods to determine, if a XenApp server is a Worker or a Controller.

Method 1:

    1. Open the AppCenter Console.

    2. Navigate to the Servers section.

    3. Click the server you want to check.

    4. In the information tab check for the Session-host Mode field.

     * if Disabled – the server is a controller     *  if Enabled – the server is a worker

Method 2:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\IMA\RUNTIME

If the DWORD value for WorkerRole is 0 then the server is a Controller and if the value is 1 then the server is a Worker.

How to switch between a Worker mode or a Controller mode?

We can switch between a Worker or Controller with the XenApp Server Role Manager:

To switch between a Worker or a Controller, complete the following procedure:

   1. Start the XenApp Server Role Manager.

   2. Remove the server from the farm.

   3. Click Configure.

   4. Click Add this server to an existing server farm.

   5. Select the appropriate database and shadowing options.

   6. In the Data Collection Option, click Enable Controller and Session-host modes.

    7. Session-host only indicates that the server is a Worker

This setting optimizes this server so it cannot serve as a Data Collector, XML Broker and does not participate in IMA elections. Since it redices network traffic and the load for the server, it is not recommended to select this option unless this zone already includes multiple Controllers.