The combination of managed hosting and dedicated power stations means that data will be increasingly concentrated in large farms. The rise of wireless devices will drive this trend too: instead of storing data internally, such devices will store information on the network and access it when needed. But users wishing to access their data will still be spread out around the world. So centralisation will drive demand for technology that can smooth out the Internet’s geographical lumpiness and speed the delivery of data; in short, technology to obscure the physical location of Internet content from its users.
First, Hide the Data
One way to do this is to store copies of popular lumps of content in data caches sprinkled around the world. The leader in this field, with over 11,000 caching servers in 62 countries, is Akamai, a firm based in Cambridge, Massachusetts. The geographical distribution of Akamai’s infrastructure is strikingly different from that of Exodus. Broadly speaking, Akamai needs servers near the consumers of content, whereas Exodus puts its farms near the suppliers of content. Accordingly, Exodus has farms in North America, Europe, Australia and Japan, but not in Africa or South America. Akamai, on the other hand, has servers pretty much everywhere.
Akamai’s customers, which include CNN and Yahoo!, are content providers who are prepared to pay to ensure that users around the world are able to access their sites smoothly and quickly. Normally, when you visit a web server, a description of the page you have requested is delivered across the network. This consists of the page’s text, plus references to any graphics (or sound or film clips) associated with it. These items are then requested by your web browser and delivered across the network. Finally, the browser assembles all the components and displays the page. The problem is that while the text can be delivered quickly, the “heavy” items (such as graphics and video) are much larger and take longer to arrive. It is these items which Akamai can help to deliver more quickly.
It works like this. You request a web page in the usual way, and the page description is delivered. But the references to the page’s “heavy” items are modified to fool your web browser into requesting those items from Akamai, rather than from the original web server. Taking account of your location on the network, and given the prevailing traffic conditions, Akamai then delivers the heavy items from the nearest available cache, and the page pops up much more quickly. By monitoring the demand for each item, and making more copies available in its caches when demand rises, and fewer when demand falls, Akamai’s network can help to smooth out huge fluctuations in traffic. A further benefit is that the customer’s web server does not have to deliver the heavy items, which reduces the load on it dramatically and makes it less likely to collapse when faced with a sudden surge of visitors.