Monitoring Citrix XenApp Servers v7 (and above)

Citrix XenDesktop 7.x represents the merging of the XenApp and XenDesktop  technologies into one cohesive package that's built on the same back-end components. Previously, XenApp servers were running on the Citrix Independent Management Architecture. Citrix XenDesktop 7.x however is built on the Citrix FlexCast Management Architecture. This architecture is made up out of Delivery Controllers and Agents. XenDesktop 7.x supports two types of Delivery Agents: one for Windows Server OS machines and one for Windows Desktop OS machines. As shown in the diagram below, both Delivery Agents communicate with the same set of Delivery Controllers and share the common management infrastructure in XenDesktop 7.x. This infrastructure consists of the following core components:

  • Receiver provides users with self-service access to published resources.
  • StoreFront authenticates users to site(s) hosting resources and manages stores of desktops and applications that users access.
  • Studio is a single management console that enables you to configure and manage your deployment. Studio provides various wizards to guide you through the process of setting up an environment, creating workloads to host applications and desktops, and assigning applications and desktops to users.
  • Delivery Controller distributes applications and desktops, manages user access, and optimizes connections to applications. Each site will have one or more delivery controllers.
  • Server OS Machines are the “XenApp” replacement – these are VMs or physical machines based on the Windows Server operating system used for delivering applications or hosted shared desktops to users.
  • Desktop OS Machines are the “XenDesktop” replacement – these are VMs or physical machines based on the Windows Desktop operating system used for delivering personalized desktops to users, or applications from desktop operating systems.

Figure 1 : The Citrix XenDesktop 7 architecture

Since these components closely co-ordinate with each other to deliver desktops and applications to end-users, a problem with any of these core components – say, the unavailability of StoreFront to authorize user logins, the failure of the broker service, performance bottlenecks with the hypervisor, resource-intensive user sessions to the Server OS machines, snags in the internal operations of the Desktop OS machines – can significantly impact the user experience with Citrix XenDesktop 7.x. Therefore, to ensure a high-quality user experience with the application/desktop delivery service, administrators should closely monitor each component of the XenDesktop 7.x infrastructure, proactively capture performance dips, and accurately isolate where the root-cause of the problem lies – is it with StoreFront? Is it with the delivery controller? Is it with the Server OS machines? Is it with the virtualized platform? Or is it with the Desktop OS machines? This is where eG Enterprise helps!

The eG Enterprise performs end-to-end monitoring of the Citrix XenDesktop 7.x infrastructure! Dedicated, web-based monitoring models are offered by eG for each component in the XenDesktop 7.x infrastructure. While the Citrix StoreFront model focuses on the health of StoreFront and promptly captures issues in user authentication, the Citrix XenDesktop Broker 7.x component monitors the Delivery Controller (or the XenDesktop broker) and reports how well it manages the delivery agents and brokers connections to the Server OS and Desktop OS machines. Moreover the Citrix XenApp 7.x model that eG Enterprise provides zooms into the overall performance and problems related to the  Server OS machines (that typically run Citrix XenApp 7) and helps isolate pain-points. Also, to monitor the resources allocated to and the resource usage of hypervisors and the Desktop OS machines operating on them, eG Enterprise offers a  specialized monitoring model per hypervisor (such as Citrix XenServer, VMware vSphere, Microsoft Hyper—V, etc.).

Detailed service topology maps in eG represent how these heterogeneous models interact with each other and how dependencies flow.

In the event of a slowdown, eG’s patented virtualization-aware root-cause analysis engine analyzes these dependencies, auto-correlates the performance results captured from the different monitoring models in the light of these dependencies, and accurately diagnoses the source of the slowdown. Proactive email/SMS/web-based alerts are then promptly sent out to administrators to alert them to the potential slowdown and what is causing it. This way, eG Enterprise emerges as the ideal solution for monitoring Citrix XenDesktop 7. x

This section deep dives into the Citrix XenApp 7.x monitoring model that eG Enterprise offers.

Figure 2 : The layer model of the Citrix XenApp server 7.x

Each layer of Figure 2 above is mapped to a series of tests that periodically check on the availability, responsiveness, and overall performance of the XenApp server, and report a wealth of performance information related to the server. Using the metrics so reported, administrators can find quick and accurate answers to the following performance queries:

Server Monitoring

  • Is the Citrix XenApp server available to service user requests?
  • Are there sporadic disconnects from the Citrix XenApp server?
  • At what times do peak usage of the servers happen and is the server capacity adequate?

User Monitoring

  • What is the average response time that critical users are seeing when connecting to Citrix XenApp?
  • How many users are logged in to each Citrix XenApp in the Citrix farm?
  • What is the resource usage (CPU and memory) for each user?

Operating System Monitoring

  • What is the average CPU and memory usage on all the servers in the farm?
  • Is any unusual memory scanning/paging activity happening on the systems?
  • Are the critical Citrix XenApp server processes processes up? What is their resource consumption?

Published Applications Monitoring

  • What are the published applications on the server?

  • Who is using each application?

  • What is the resource usage for each published application?

The Operating System, Network, TCP and Windows Service layers of the Citrix XenApp are similar to that of a Windows server model. Therefore, refer to the Unix and Windows Monitoring model for detailed discussion about these layers.