Welcome!

Blog Feed Post

Why Web Performance Matters – Comprehensive CDN Monitoring

Waiting for a webpage to load can be painful—but not knowing how to proceed when the page is “stuck” is a nightmare. User satisfaction is dependent on website performance and ease of use – a slow loading website has a negative impact on end-user experience and directly affect conversion rates. To ensure high availability and performance, companies often turn to CDNs to speed up the delivery to the last mile by reducing latency; however, CDNs rely on a very complex infrastructure thus prone to failure as well.

Performance monitoring has expanded well beyond just webpage performance – to understand the big picture, monitoring must track every component that drives the digital experience of a user which includes the Content Delivery Network. The common belief is that using a CDN serves the content faster based on the visitor’s geographic location to reduce latency and improve the performance of the website. Any issue with a CDN (DNS, outage, DDoS) can lead to several points of failure in the content delivery process.

Our support team had recently handled an issue affecting one of the top travel aggregator websites and the root cause analysis of the issue illustrates exactly why you MUST have a CDN monitoring strategy in place.

The travel website uses a major CDN for acceleration; our tests started reporting failures on 02/07/2017 00:30 PT. When users navigated to the site and searched for available flights, the page was stuck in a continuous loop.

screen-shot-2017-02-28-at-9-38-56-amhttp://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 300w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 768w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 624w" sizes="(max-width: 859px) 100vw, 859px" />

End users located in Portland and Seattle were affected whenever the content was served from this particular Edge Server. During this time frame, availability of the search page from Portland and Seattle were 11.11% and 89.9%, respectively. The users from Portland could not search for flights on this major travel website.

screen-shot-2017-02-28-at-9-39-55-amhttp://assetsblogfly2.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 300w, http://assetsblogfly2.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 768w, http://assetsblogfly2.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 624w" sizes="(max-width: 878px) 100vw, 878px" />

During the same timeframe, cities like Dallas, Atlanta, and New York experienced availability of 99.12%, 99.47%, and 98.19%, respectively.

screen-shot-2017-02-28-at-9-40-36-amhttp://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 300w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 768w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 624w" sizes="(max-width: 871px) 100vw, 871px" />

Using our capability to override DNS for specific hosts, we could confirm that the issue was specific to a CDN server. Further investigation helped us narrow down the issue to their West Coast Edge Server. The server was returning zero-length Javascript files, which rendered the search page blank and unable to pull/display results.

The graph below shows the drastic dip in the number of script files and the corresponding script bytes, which was clearly causing the issue on the website.

screen-shot-2017-02-28-at-9-41-23-amhttp://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 300w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 768w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 624w" sizes="(max-width: 891px) 100vw, 891px" />

The dip in script bytes was observed from a specific IP alone. This helped isolate the issue to one of their nodes. The issue was resolved and normal function was restored to the website once the CDN purged all the Javascript files.

Example of a response header captured:

screen-shot-2017-02-28-at-9-42-14-amhttp://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 300w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 768w, http://assetsblogfly1.catchpoint.com/wp-content/uploads/2017/02/Screen-S... 624w" sizes="(max-width: 878px) 100vw, 878px" />

This was a classic example showcasing the importance of monitoring critical user journeys to understand the impact/influence of CDN performance on your web assets’ functionalities and, once again, highlights the importance of monitoring all components.

It is said, “every failure is simply the opportunity to begin again, this time more intelligently.”

Here are some key CDN monitoring strategy tips:

  • Always monitor the origin and the CDN to quickly identify the issue (is it the CDN or is it the origin?)
  • Monitor common JS, CSS, Image (pick the top 3 resources – top 3 CSS files, 3 top js files…) and monitor both origin and CDN version.
  • On the CDN side, use a random number to keep the CDN honest (example: http://www.company.com/logo.jpg?$randomnumber)
  • Capture Headers and pass the appropriate debug headers for faster troubleshooting
  • Hit the robots.txt on both origin and CDN (example http://origin-abc.com/robots.txt and http://www.abc.com/robots.txt) http://blog.catchpoint.com/2012/01/19/best_friend_robots/
  • Ensure that your origin is properly configured to talk to the Edge (is chunked-encoding enabled? Bad idea!)

The post Why Web Performance Matters – Comprehensive CDN Monitoring appeared first on Catchpoint's Blog.

Read the original blog entry...

More Stories By Mehdi Daoudi

Catchpoint radically transforms the way businesses manage, monitor, and test the performance of online applications. Truly understand and improve user experience with clear visibility into complex, distributed online systems.

Founded in 2008 by four DoubleClick / Google executives with a passion for speed, reliability and overall better online experiences, Catchpoint has now become the most innovative provider of web performance testing and monitoring solutions. We are a team with expertise in designing, building, operating, scaling and monitoring highly transactional Internet services used by thousands of companies and impacting the experience of millions of users. Catchpoint is funded by top-tier venture capital firm, Battery Ventures, which has invested in category leaders such as Akamai, Omniture (Adobe Systems), Optimizely, Tealium, BazaarVoice, Marketo and many more.

Latest Stories
What if you could build a web application that could support true web-scale traffic without having to ever provision or manage a single server? Sounds magical, and it is! In his session at 20th Cloud Expo, Chris Munns, Senior Developer Advocate for Serverless Applications at Amazon Web Services, will show how to build a serverless website that scales automatically using services like AWS Lambda, Amazon API Gateway, and Amazon S3. We will review several frameworks that can help you build serverle...
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
VeriStor Systems has announced that CRN has named VeriStor to its 2017 Managed Service Provider (MSP) 500 list in the Elite 150 category. This annual list recognizes North American solution providers with cutting-edge approaches to delivering managed services. Their offerings help companies navigate the complex and ever-changing landscape of IT, improve operational efficiencies, and maximize their return on IT investments. In today’s fast-paced business environments, MSPs play an important role...
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor - all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure network...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm. In his Day 3 Keynote at 20th Cloud Expo, Chris Brown, a Solutions Marketing Manager at Nutanix, will explore t...
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Have you ever noticed how some IT people seem to lead successful, rewarding, and satisfying lives and careers, while others struggle? IT author and speaker Don Crawley uncovered the five principles that successful IT people use to build satisfying lives and careers and he shares them in this fast-paced, thought-provoking webinar. You'll learn the importance of striking a balance with technical skills and people skills, challenge your pre-existing ideas about IT customer service, and gain new in...
"When you think about the data center today, there's constant evolution, The evolution of the data center and the needs of the consumer of technology change, and they change constantly," stated Matt Kalmenson, VP of Sales, Service and Cloud Providers at Veeam Software, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
@DevOpsSummit at Cloud taking place June 6-8, 2017, at Javits Center, New York City, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long developm...