Content Delivery Networks – Demystified

Yesterday I wrote about Amazon’s entrance into the Content Delivery Network (CDN) space with their newest web service offering. CDN’s are not a new technology and this is actually a crowded market – one that Amazon hopes to enter and commoditize.

What is a Content Delivery Network?
In layman’s terms a CDN provides the ability to deliver content in a scalable, highly available, and cost-efficient way. If you want a more technical explanation (who does?) here’s what Wikipedia has to offer:

Modern CDN’s can dynamically distribute assets to strategically placed redundant core, fallback and edge servers. Modern CDN’s can have automatic server availability sensing with instant user redirection. A CDN can offer 100% availability, even with large power, network or hardware outages.

Modern CDN technologies give more control of asset delivery and network load. They can optimize capacity per customer, provide views of realtime load and statistics, reveal which assets are popular, show active regions and report exact viewing details to the customers. – via Wikipedia

As I mentioned, Amazon is entering a crowded market with the likes of Akamai, Limelight, and CDNetworks. Luckily they have a good start with their Simple Storage Service (S3) – which will provide the backbone of their new CDN.

How does a content delivery network work?
Here is a simple example…

What does this mean for you?
Ahh the big question… I can just see Doug asking – “All this tech crap is cool but how will this help me?” Well, since you asked I’ll tell you how we use a CDN at 48Web. We don’t use anything fancy at this point – just Amazon S3. Simply enough – we use it to host *stuff* so we don’t have to worry about our websites going down due to the increased load – which helps us scale. We learned this lesson when we launched Iowa Flood (our citizen journalism experiment). Within hours of launching we were getting hit with thousands of requests every few minutes. Needless to say our shared hosting environment for our “experiment” couldn’t handle it. In order to offload most of the strain we moved all the multimedia content to Amazon S3. Our thoughts were “let them worry about handling this load” while we concentrate on our user’s experience.

We also use this in our product development. In order to take the strains off our server we host our images, icons, javascripts, css, etc on S3. This takes the load off our servers and lets it scale much easier. At that point all we need to worry about is how efficient our connectivity is to our database – as we let the CDN take care of all our “assets”. We’re developers – not System Administrators. A CDN gives us a worry free distribution model that is VERY cheap.

How much does this stuff cost?
Current CDN solutions are very expensive but I have a feeling that Amazon is going to completely undercut the CDN market by offering their standard “pay for only what you use” approach which is great. It helps small companies (like us) scale based on demand. Our monthly bill for Amazon S3 is often under $5/mo. I am hoping their CDN can offer similar prices.

—-

As usual if you have any questions about CDN’s, leave a comment. If you want to know how your company can leverage this awesome technology, feel free to Ask Andy.

If you enjoyed this post, make sure you subscribe to my RSS feed!

,

One Response to Content Delivery Networks – Demystified

  1. doug mitchell October 30, 2008 at 5:21 pm #

    why yes andy…i was just saying, “so what does this matter to me….get to the bottom line” and u delivered :)
    i can always count on u for that…and i guess that’s why we work together.

    andy, you’re like the peanut butter and i’m like……..omg. later.

Leave a Reply