Monitoring CDN
21 Jul 2019

Monitoring your CDN to Optimize Performance

Monitoring your CDN is vital in ensuring your service delivers the performance your web application needs. As with any other technology service, a Content Delivery Network (CDN) needs the appropriate level of oversight so that you can resolve any identified issues proactively. In addition to monitoring your CDN for any performance or config related problems, continuously keeping an eye on your CDN metrics can also help you identify any bottlenecks and tweak your configuration for optimum speed. A CDN solution typically involves various technologies that include networking, protocol, and storage services. Working in unison these technology solutions depend on each other to deliver the superior performance and availability demanded by today’s modern Internet user. Monitoring these platforms and services can help you optimally configure your CDN and identify any issues before they detrimentally impact your web application.

Monitoring Your CDN Nodes

When it comes to tracking the performance and availability of your CDN, there are a wide variety of metrics that assist you in determining the overall speed and functionality of your service. The global distribution of traffic, response times from the various CDN nodes, and the performance of the network backbone are all vital in ensuring an optimal CDN service.

Due to its distributed architecture, it is crucial to monitor your CDN paying particular attention to the user experience at every location. Since every node needs to deliver the appropriate content to your site visitors wherever they are located, it is vital that you monitor the availability and response times of every node in your service. Without this global view of granular availability, you would not be able to identify if a particular region is not meeting its performance thresholds. If you only monitor one specific location, you may incorrectly assume that the metrics are the same everywhere. This assumption may lead you to miss performance or availability issues affecting your site visitors in other locations. Monitoring the end-user experience leveraging a stable connection from each region is therefore vital in ensuring your CDN is performing optimally. Modern tools give you the capability to measure ping and HTTP load times from multiple sensors located across the Internet. Leveraging these services, you can measure the actual performance of every CDN node in real-time.

Monitoring Your Origin Server

The web application your site visitor interacts with consists of multiple web assets that together form the web page. These components comprise of static resources such as text, images, stylesheets, and script files. However, a modern web application also delivers dynamically generated content that is derived from the user’s interaction and profile. Typically, the user’s browser or app receives the static components from the CDN and the dynamic content from the site or services’ origin server. As the application depends on every web asset loading correctly and timeously, should any component fail, it can degrade the user experience.

Monitoring the health of your origin server is therefore vital as it forms an integral part of your solution. Measuring typical web metrics such as uptime, HTTP responses, and latency as well as server specific measures such as CPU, memory, and storage utilization is vital in ensuring the functionality and performance of your site. All of these various technological components working in unison provide your web application with the functionality needed to process requests and render the web page to your site visitor. Should any of these elements fail or decline into a degraded state, it could impact both the dynamic content sent directly to the user as well as the performance of your CDN service.

Optimal CDN Mapping

In the CDN industry, mapping refers to the algorithm your service provider utilizes to ascertain which of its globally distributed nodes is the closest to the user at the time they initiate a web request. However, due to the architecture of modern global networks, the closest CDN node to a particular user may not be the nearest in terms of geographic proximity. In the CDN world, the closest node is measured by network latency and ping response times. Depending on a variety of factors such as network speed and available bandwidth, your CDN then calculates the best route each request should take to ensure the best possible experience for your site visitors. Taking metrics from your monitoring solution that measures response times from sensors located close to your distributed user base, helps you ensure your CDN is optimizing the mapping of your service.

Optimizing Your CDN

Monitoring your CDN not only gives you the metrics you need to ensure your CDN mapping is configured as optimally as possible, but it also gives you insights into other services you can refine to configure your CDN for peak performance. Testing your CDN regularly while continuously monitoring your service has several benefits that help you get the most out of your service. Not only do you get proactive alerts to ensure your services are fully functional, but it also allows you to benchmark and assess your CDN performance regularly.

Testing, optimizing, and monitoring elements such as your DNS service and response times helps you fine-tune your CDN mapping, caching configuration, and other services that rely on timely responses to DNS queries. In addition to DNS, ensuring you configure, test, and monitor your TLS connection times can also help optimize your CDN service. As HTTPS is vital in today’s cloud-first, mobile world where search engines and browsers insist it be the de-facto protocol, any CDN monitoring service needs to have the capability to measure it. Your CDN’s cache hit ratio is another metric that you should continuously monitor to ensure you get the best possible experience for your site visitors. By tracking this metric, you have the insights you need to tweak settings such as your HTTP cache-control headers that maximize and optimize the performance of your CDN.

Monitoring Your CDN Helps Ensure Peak Performance

Like every other technology you deploy to maximize the performance and functionality of your website, your CDN needs continuous monitoring. Having access to these vital metrics not only allows you to detect and remedy any issues proactively but also gives you the insights you need to fine-tune your service, ensuring your site visitors get the best experience possible. By monitoring your service from your origin server to every node in the CDN, you can identify performance bottlenecks, tweak your configuration, and hone your solution so that it meets the needs of today’s demanding Internet users.