Welcome!

Industrial IoT Authors: Elizabeth White, Stackify Blog, Yeshim Deniz, SmartBear Blog, Liz McMillan

Related Topics: Machine Learning , Java IoT, Industrial IoT, Microservices Expo, Microsoft Cloud, Containers Expo Blog

Machine Learning : Blog Post

Filling the Citrix Visibility Gap with an Application-Aware Network

Monitoring the end-user experience of applications

Citrix XenApp or XenDesktop is a perfect fit for lowering the costs of desktop management and simplifying access to the hosted applications from any device. Last week we discussed some challenges to application performance monitoring (APM) introduced by Citrix. Apart from getting yet another component in the data center to take care of, the virtualized application delivery becomes "black boxed" from the APM perspective. It gets harder to isolate the fault domain to the network, the infrastructure, or the applications themselves.

In the previous post we presented the case of The National Bank of San Borodin (NBSB -name changed for commercial reasons). The bank decided to expand its reach beyond the small island of San Borodin and render the access to its banking applications by its agents through Citrix XenApp. Ensuring good quality of service imposed additional challenges on the operations team. We analyzed how to discover and handle performance issues that can happen in the Citrix enabled environment in the last post. Today, we'll look into monitoring the end-user experience of applications delivered through Citrix.

End-User Experience
Whatever the cause of the application performance problems is, regardless of whether the application delivery is virtualized by Citrix XenApp/XenDesktop or not, in the end, it's all about the end-user experience. In order to efficiently manage user experience we should be able to identify users and analyze each person's experience.

Therefore it's indispensable to use an application-aware network performance monitoring (aaNPM) tool that can correlate end users to their interaction with applications virtualized with Citrix (see Figure 1).

Figure 1: Citrix-enabled architecture with an application-aware network performance monitoring (aaNPM) tool that is capable of analyzing the ICA protocol, understanding user sessions, seeing inside Citrix farm with Thin Client Analysis Module (TCAM) and monitoring the actual backend applications

The Operations team at NBSB used an aaNM tool to monitor the experience of the most active Citrix users (see Figure 2) and list each operation executed by the user (see Figure 3).

Figure 2: Checking the user experience of the most active users

Figure 3: Monitoring application performance through the actions of a single user

Monitoring Citrix Channel Consumption
As we mentioned before, a reliable network is very important to ensure the high performance of applications delivered by Citrix. Even though Citrix is designed to require less bandwidth than other remote desktop solutions, this cannot be attributed to all virtualized applications. Multimedia, printing or accessing local USB drives require much higher bandwidth and can lead to performance problems of the main applications.

Figure 4: Performance per Citrix channel shows that even with 25 users the Thinwire channel has much higher server realized bandwidth than other channels, e.g., Graphics that cannot deliver the same user experience even for only two users

The operations team used the aaNM reports to track bandwidth consumption and user experience across different Citrix channels (see Figure 4) and listed users using a selected channel (see Figure 5).

Figure 5: Listing users accessing one of Citrix channels

Applications Not Designed for Citrix
Performance problems may also occur when a secondary application, i.e., used by a minority of users, competes for the resources with the primary application. This happened at NBSB when one such application worsened the performance of the primary one on one of the Citrix servers (see Figure 6). As in our previous post, the operations team was able to isolate the fault domain by looking at the Server realized bandwidth even though, the overall Network performance did not indicate any problems.

Figure 6: Exotic application (WebClient), not designed for Citrix, can consume resources that should be otherwise used by the main application (NBSB Access Exp)

The Operations team wanted to determine why the WebClient application affected other applications so much. They consulted the Operations report (see Figure 7) and saw that some users visited an online casino site frequently; that site happens to be a heavily interactive Web 2.0 service. The site transferred a lot of small files that affected the performance of other applications because Citrix could not leverage its delivery virtualization capabilities and had to transfer a lot of raw data across the network.

Figure 7: Accessing web applications via Citrix is not a good idea. Here some users were cannibalizing performance of key applications by playing online games

Performance Problems at the Client Side
End-user performance problems can be also caused by the problems at the Citrix thin client side. The operations team received an alert on a growing number of TCP zero window events indicating Citrix client problems (see Figure 8) that might happen on machines that are busy performing other tasks. They discovered when these problems occurred, the banking agent, who was at the customer's office, was printing a loan contract for his client using a local printer. The printing process consumed most of the resources of the netbook he used and slowed down the Citrix thin client to a level at which the process could not respond on time to traffic incoming from the Citrix server.

Figure 8: TCP Zero Window problems reported by the aaNM tool

Conclusion
When many employees need to access the same desktop application it might be more convenient to use delivery virtualization technology such as Citrix XenApp/XenDesktop to provide the same user experience to all of them; regardless of what device they use, from a desktop computer to a tablet, all employees can use the same application without an IT team setting them up. However, there is catch: Citrix needs a reliable network to ensure an unaffected end-user experience. Hence the operations team gets a new challenge in application and network monitoring.

Last week we showed how to monitor network performance to ensure proper distribution of load over both Citrix servers and the backend servers.

In this post we illustrated that certain issues may only affect (or be caused by) some users at certain locations. The operations team at the National Bank of San Borodin required a holistic and in-depth end-to-end view of the whole application delivery to find the root cause of the problems. They achieved that by using Compuware APM Application-Aware Network Monitoring, a tool that enabled them to monitor not only the network, the infrastructure and the applications, but also analyze the end-user experience for degradation of the quality of service of applications and desktops delivered with Citrix XenApp/XenDesktop.

More Stories By Sebastian Kruk

Sebastian Kruk is a Technical Product Strategist, Center of Excellence, at Compuware APM Business Unit.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


IoT & Smart Cities Stories
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
Cell networks have the advantage of long-range communications, reaching an estimated 90% of the world. But cell networks such as 2G, 3G and LTE consume lots of power and were designed for connecting people. They are not optimized for low- or battery-powered devices or for IoT applications with infrequently transmitted data. Cell IoT modules that support narrow-band IoT and 4G cell networks will enable cell connectivity, device management, and app enablement for low-power wide-area network IoT. B...
The hierarchical architecture that distributes "compute" within the network specially at the edge can enable new services by harnessing emerging technologies. But Edge-Compute comes at increased cost that needs to be managed and potentially augmented by creative architecture solutions as there will always a catching-up with the capacity demands. Processing power in smartphones has enhanced YoY and there is increasingly spare compute capacity that can be potentially pooled. Uber has successfully ...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...