Edward M. Goldberg

Cloud Computing - News and Ideas

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Content Delivery Networks (CDN)

What is a CDN?

What is a CDN good for?

Before this week CDN may not have been part of your vocabulary.  Now that AWS CloudFront is launched the buzz around the forums is all about CDN and the good and bad (lack of) features in CloudFront.

Basics;  A CDN has two basic parts,

  1. The origin server is where the bits and bytes of your master html files com from.
  2. The CDN Network of servers, are where the users get the service.

The idea is very simple.  It works like a cache.  You provide once a day or so,  a copy of the content.  The CDN provides a copy each time the file is served to user.  Nice and simple.

But the details,  that is where this whole idea gets complicated.  The CDN also services these requests from the closest (in network time,  not miles) server to the user.  The “Feature” adds more performance for remote users.  I could go on and on about cache features and details,  but it would just make you dizzy.

So, why is this AWS CloudFront service special, you ask?

Till now most of the CDN providers started to want to talk to service users when the volume of data got to $1,000.00 each month.  Wow,  not many small servers need that level of service.  But is it great when you need it …..  AWS CloudFront can be used starting at $0.15 for each month.

With this lean feature AWS CDN at rates too low to ignore and NO lock-in or low end minimums we need to start talking more about why low end sites should use CDN Technology.

For many sites CloudFront can help make the site Slash-Dot proof.  Content served from a CDN scales with the demand for the service.  For sites that are NOT in EC2 today can use CDN services to provide capacity that scales with need for even one page or download.

The ecosystem has changed.

CDNs are not new.  Just the cost and lock-in levels have changed.

UPDATE:

A question was just posted on the AWS FORUM about very small items like icons costing more for CDN than hosted service.  This could be very true for some sites.

The questions you have to think about are:

Does faster load time in these area matter for your site?

United States

  • Ashburn, VA
  • Dallas/Fort Worth, TX
  • Los Angeles, CA
  • Miami, FL
  • Newark, NJ
  • Palo Alto, CA
  • Seattle, WA
  • St. Louis, MO

Europe

  • Amsterdam
  • Dublin
  • Frankfurt
  • London

Asia

  • Hong Kong
  • Tokyo

Does is matter that CDN has 99.999 levels of supprt?

Your site may not take a full load of a real “Slash Dot” level is request.  The CDN will take that load level.