CDN Load Balancing and Content Distribution Networks Could Save Target.com From Going Down

Poof or Woof!?

Target website goes down due to unpredicted load caused by a Missoni promotion on the website.

Yes, even the largest online retailers can blow it when they don't take a detailed look at how their servers are designed to handle the load of too many visitors all at once.  My experience with the ATP Tour and the WTA Tour with the sage mentoring by Phil Dore, Director of Marketing for the ATP taught me that designing cool sites is ok, but designing the plumbing and infrastructure to handle peak load was even more important.

A Simple Website

This is a simple diagram showing how a traditional website is launched with a database server, an application server and then the client PC that is bringing over the HTML pages and content.  Simple and extremely dangerous!  Your exposure to peak load is equal to the number of visitors to your website.  This means that 1,000 visitors load 20,000 pages which causes 20,000 calls to your application server and 100,000 calls to your database (average 5 db calls per page and 20 pages per visit)

An Edge Cached Website

Compare that to the next diagram that leverages a content distribution network or "Edge Cache" to absorb the traffic load and stop the exponential load on your server.

Note here we shield our database server and our application server from the huge surge of traffic by fronting it with an edge cache server or CDN (Content Distribution Network).  This is not the same thing as a "Cloud Computing Device" although you can setup a CDN on a cloud platform.  Here any time a page is loaded the first time, you see 5 database calls render the page and then it is copied in static form to the Edge Cache Server where it remains for a designated time (TTL or Time to Live).  Many cases we will set the TTL to 24 hours so the page will persist, in static form for a full day.  Here, 1,000 visits generate 1,000 hits to the Edge Cache Server, statistically generating 0 hits to our application server and 0 hits to our database server (over time it approaches zero).

So, Target, I hope you've taken a look at your CDN infrastructure and for those businesses that haven't be sure that you contact me for a "load analysis" on your website to make sure you don't fall prey to same "Poof" condition on your website that Target is facing today... Woof Woof!