Digital Edition

SYS-CON.TV
Welcome to the Show of Content Delivery Networks
Act 1 – The What and Why

"Step right in. You will witness a show of magic and wonders, passion and trust, speed and misunderstandings." a (slightly altered) catch phrase that keeps popping in my head when talking to companies in regards to managing Content Delivery Networks (CDN). Apart from the misconception that a CDN will solve all performance problems one of the great unknowns seems to be how to actually monitor CDNs the right way. And as we all know: you can't manage what you don't understand! So in three "Acts" I will walk you through the main purpose of CDNs, how such systems have to be monitored and what dirty unknowns the right strategy can bring to the surface.

Years ago I was a member in an Off-Theatre group in Berlin. Why that would have any relevance to the CDN topic, you may ask. Part of our maturity journey resembles what almost all companies go through when they end up paying for a CDN service. We were a passionate group, lots of talent (of course), lots of energy and had a dedicated fan group. However we had the same challenge as all off-theatre groups have: no budget, hence no real publicity from a marketing perspective. We started printing flyers and postcards to promote the show. First small numbers and then more and more putting them in pubs, restaurants, book shops, etc. While happy with the result the whole thing stole a lot of our time. So we began to delegate: friends and fans would distribute and in return get free tickets. After a while we realized that we needed to get into better locations like Hotel lobbies and other flyer stands, which however were controlled by marketing agencies.

So we decided to look for one which would help us out and a whole cascade of questions had to be answered:

  • Which one has the best offer?
  • Where and how should they distribute our content?
  • Can they help us with the decision and if so do/can we trust their judgment?
  • How soon do we need to make our decision and how quickly can they react to our needs?
  • How can we be sure they deliver what they promised?
  • Will the money we spent be worth it?

And these are questions which certainly should look familiar if you've ever had to deal with a CDN.

What is a CDN?
In a nutshell CDNs are helping IT teams either by taking on a large bulk of the traffic or by decreasing the latency. They typically have a large network server or points-of-presences (PoPs) spread across the globe. Historically these PoPs were basically used as caching tiers which are much closer to the end user then the origin servers of your own data center. Today of course the CDNs have become much more advanced handling complex route optimization, content compressions, etc., but for the purpose of explaining the right monitoring strategy the simplified explanation of a widely distributed network of servers instead of just 1 centralized data center is enough - also it's the core aspect everyone thinks of when they hear CDN. The most important thing though is that they should speed up things for the end user with less investment then trying to do it in house.

Why use a CDN?
15 years after my theater adventures, I now realize that the services the marketing agencies offer, are exactly the same in the "real world" as the CDNs offer in our digital world today. They help getting the content closer to the customer, making it very convenient to access it. Used the right way they can have a very positive business impact - even when the initial investment seems to burn a big hole in the IT budget. And their service can grow with your business starting locally to simply ensure the scalability of your venture all the way to reaching far away locations across the globe.

Reducing Latency
Looking at a typical, internationally operating B2B manufacturing company or an international financial institution the main CDN benefit is getting the content much closer to the users spread across the globe and thus minimizing the latency and increasing the performance. Factors like decreased DNS, connection and first byte times are their main motivators.

Externalizing Load Balancing
Another scenario of a heavy traffic site like the popular German magazine Spiegel.de where most of the traffic is coming from within Germany on the other hand would benefit by outsourcing the handling of the load and thus minimizing the number of requests hitting their own infrastructure. So the hit/miss ratio is an important factor judging the efficiency of the CDN. Hit in this case meaning the content was served straight from a CDN PoP and miss meaning the content had to be fetched by the CDN from the origin before it could serve it to the end user thus still creating an impact in the data center. Such a traffic reduction on the origin can of course also be used cleverly to minimize the impact of denial of service attacks.

Primary CDN use cases: load balancing and latency reduction

And of course mixes of these 2 main benefits like high traffic sites with international reach or outsourcing relatively few but large file downloads are relevant as well.

So the two main things to look for when it comes to CDN investments are:

Does the CDN help to achieve the overall goal of performance improvement for the end user by:

  • Decreasing latency (dns resolution, connection speed, 1st byte time)
  • Decreasing load on own infrastructure (hit/miss ratio)

and by how much?

Scarily enough over the years I have realized that many companies in the end base their decision on which CDN to choose on gut feeling and guesswork. Many do run an evaluation project, however in most cases the methodology of these projects is questionable.

What to look at when choosing a CDN?
While many aspects like pricing or relationship and trust are of course important in choosing the right vendor I want to focus on the main purpose of the CDN - fast delivery to the end user.

And to be able to make informed decisions and not just guessing about the current situation you need to be confident in answering the following questions. Click here to learn what questions you need to be asking - and what answers you need to be looking for regarding a CDN.

The old way of monitoring doesn't work and not having control over the situation can be disastrous!

About Kristian Skoeld
Kristian Skoeld is a Performance Analyst at Compuware APM Center of Excellence. He coaches and supports teams across Europe as a Performance Analyst and Product Specialist in Web Performance Management. He is an expert in optimizing IT processes, develop web strategies and putting them into action, and a subject matter expert on Web Performance and Web Monitoring within the Compuware APM business unit.

In order to post a comment you need to be registered and logged in.

Register | Sign-in

Reader Feedback: Page 1 of 1



ADS BY GOOGLE
Subscribe to the World's Most Powerful Newsletters

ADS BY GOOGLE

@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22...
CloudEXPO New York 2018, colocated with DXWorldEXPO New York 2018 will be held November 11-13, 2018,...
DevOpsSummit New York 2018, colocated with CloudEXPO | DXWorldEXPO New York 2018 will be held Novemb...
DXWorldEXPO | CloudEXPO are the world's most influential, independent events where Cloud Computing w...
Disruption, Innovation, Artificial Intelligence and Machine Learning, Leadership and Management hear...
In this Women in Technology Power Panel at 15th Cloud Expo, moderated by Anne Plese, Senior Consulta...
Enterprise architects are increasingly adopting multi-cloud strategies as they seek to utilize exist...
Enterprises are striving to become digital businesses for differentiated innovation and customer-cen...
DXWorldEXPO LLC announced today that Telecom Reseller has been named "Media Sponsor" of CloudEXPO | ...
"We host and fully manage cloud data services, whether we store, the data, move the data, or run ana...
Containers and Kubernetes allow for code portability across on-premise VMs, bare metal, or multiple ...
"Akvelon is a software development company and we also provide consultancy services to folks who are...
In this presentation, you will learn first hand what works and what doesn't while architecting and d...
DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, ...
Most DevOps journeys involve several phases of maturity. Research shows that the inflection point wh...
Modern software design has fundamentally changed how we manage applications, causing many to turn to...
In his session at 20th Cloud Expo, Scott Davis, CTO of Embotics, discussed how automation can provid...
In his session at 20th Cloud Expo, Mike Johnston, an infrastructure engineer at Supergiant.io, discu...
Founded in 2000, Chetu Inc. is a global provider of customized software development solutions and IT...
Dynatrace is an application performance management software company with products for the informatio...