Citrix Delivery Controller v3-4 Monitoring Using eG Enterprise
Figure 1 is a high level view of the architecture of XenDesktop 3.
As can be inferred from Figure 1, the Delivery Controller farm serves as the hub for the XenDesktop Architecture. The controllers in the farm are responsible for managing the pools of available virtual desktops as well as directing and monitoring user connections to the virtual desktops. Versions 3/4 of DDC are based on the CPS (XenApp) technology. It uses MFCOM/IMAProxy to communicate with the Access Management Console (AMC), which uses DCOM and Windows Communication Foundation (WCF). It communicates with the Web Interface using the XML service, just as XenApp does. The IMA service is used to communicate with other DDCs in the farm, with the License server, and the Datastore, just as with XenApp. The DDC also includes a Pool Manager, which is responsible for choosing a VM from the Desktop Group and assigning it to a user. Once the appropriate desktop operating system is identified, the Controller service of the DDC queries the Active Directory for user authorization and then sets up the PortICA user connection to the target VM. The DDC also includes a User Profile Manager, to manage user personalization settings in virtualized or physical Windows environments.
The DDCs use a central DataStore that contains static configuration information, such as desktop pool configuration, DDC membership and farm settings. VDA configuration data is also stored in the datastore.
In summary, the DDC integrates the following core technologies:
- Dynamic pooling, on-demand assignment, and pre-assignment of virtual desktops to users, based on appropriate policies, roles, or other criteria
- Fast, resilient connections, even over high-latency or bandwidth-constrained networks, using the ICA protocol, which includes SpeedScreen technologies
- Integration with virtualization infrastructures, enabling administrators to dynamically manage the state of virtual desktops to make best use of resources, deliver instant-on experience for the user, and enable the reversion to a known state of pooled desktops after each use
- A central management interface for all virtual desktops, whether they are VM-based, blade-based, or PC-based
Failure of any of these core functionalities may not only affect the performance of the broker, but can even temporarily/permanently suspend the XenDesktop service as a whole. If such adversities are to be averted, the Delivery Controller has to be monitored 24x7.