Agentless performance monitoring and Citrix XenApp

Citrix XenApp is widely used to facilitate the access of remote users to applications. In many cases of performance complaints and degradations, Citrix XenApp is one of the links which need to be analyzed. SkyLIGHT PVX’s agentless performance monitoring approach is an effective means of understanding Citrix XenApp performance and identifying performance degradations.

SkyLIGHT PVX applies its application recognition engine to identify and monitor Citrix XenApp / ICA traffic (from thin clients to XenApp servers) and Citrix-hosted applications (from XenApp servers to the application servers), mapping their traffic volumes and reporting performance indicators to the real-time and historical reports of the GUI.

Agentless Performance Monitoring of Citrix Applications

SkyLIGHT PVX’s agentless performance monitoring approach — with probes placed at strategic capture points on the network —  enables it to collect and provide rich insight on the utilization and performance of each published Citrix application. Network administrators can then proactively manage faults, monitor individual Citrix-based applications, plan capacities, and troubleshoot performance degradations of Citrix architecture.

 What’s the context?

A Citrix XenApp solution is usually implemented to control operational costs (like bandwidth) and improve the delivery of applications throughout the network.

However, Citrix solutions hides individual application traffic flows and application response time, making it difficult to identify individual Citrix applications on the network.

Technical background on Citrix XenApp

Citrix XenApp Presentation Server acts as an application proxy that exchanges with the thin client information such as mouse moves and clicks, screens, keyboard strokes, etc. This information is transported through an SSL secured tunnel, which hides the nature of the information carried between the Citrix XenApp server and the thin clients. The only information appearing in clear text is the priority bit, which is related to the type of data conveyed (mouse, screen, keyboard, etc…).

On the other hand, the Citrix XenApp server acts as the original client to process application requests and receive responses from the “traditional applications”.

This means that all ‘users’ are seen with a single client IP address (which is the Citrix server).

Unless you can decrypt the SSL-tunnel or position an agent on the Citrix XenApp server, there is no possible way of tracking individual application transactions from the thin client to the application server.

Main operational questions raised around Citrix with SkyLIGHT PVX

Citrix XenApp is implemented to save network operating costs and to centralize management of workstation configurations.

• How do you evaluate the volume of Citrix traffic flowing from/to different network segments? (Which clients are using the most bandwidth?)
• Are the network conditions providing a good environment for Citrix XenApp (i.e., stable network latency, no packet loss or retransmission)?
• How will you identify and resolve troubleshooting and capacity planning issues between Citrix applications and other applications?

Citrix applications are usually mission-critical applications for an organization; any performance degradation will directly affect end users and overall business productivity.

• How will you discover when performance and response times degrade?
• How will you be able to pinpoint the root cause of the degradation (e.g., network, Citrix or application led)?
• Which user constituencies are impacted by Citrix performance degradations?
• Which Citrix server is impacted by an application performance degradations?

SkyLIGHT PVX provides insight on the performance of the Citrix Presentation Server as well on the performance of the applications accessed through it.

Monitoring Application Performance with SkyLIGHT PVX

SkyLIGHT PVX meets the network management team’s need for performance management in Citrix deployments by enabling them to:

• Evaluate Citrix utilization by identifying both Citrix XenApp (from user to Citrix server) and Citrix application traffic (from Citrix server to external application servers)
• Analyze Citrix-based applications and other applications simultaneously
• Maximize the performance of Citrix XenApp by monitoring both the response times of the Citrix XenApp layer and the response times of the applications published in Citrix

Citrix-oriented features in SkyLIGHT PVX

1. Network performance monitoring (NPM) for Citrix: Citrix XenApp’s performance is mainly driven by network performance indicators like round-trip times and packet loss/retransmission levels. SkyLIGHT PVX provides synthetic indicators to enable infrastructure teams to proactively ensure that the best conditions are in place for Citrix XenApp to run smoothly.
2. Bandwidth analysis: SkyLIGHT PVX provides a complete insight on to network utilization linked to Citrix and helps IT teams understand how the Citrix usage is spread over the network and how Citrix competes with other applications for network resources.
3. Application performance monitoring for Citrix Applications: in complement to measuring application response times for Citrix XenApp, SkyLIGHT PVX can provide synthetic and detailed troubleshooting data on the performance of the applications accessed through Citrix servers (from dashboard to transaction-level information in 4 clicks).