The ‘cloud’ stands for a worldwide infrastructure of computers that can deliver applications and content to any place on the Internet. Early examples of clouds are content distribution networks (CDN), which can serve web content from a worldwide distributed network of servers. Because the servers are closer to the user the user will see quicker response. Because there are multiple servers, larger numbers of users can be served.
I have done some measurements on the proximity of a number of content distribution networks to monitoring stations around the world. Earlier I reported on the distance that the Google Application Engine (GAE) has to the cloud. Here we do the same for more content distribution networks. Note that GAE actually allows to run applications on the cloud, and we are using here only its capacity to serve content.
The monitoring stations by Watchmouse are situated in 35 locations on all continents of the world. The minimum connect time to a provider as measured from a particular location is a good indicator of the distance to that provider.
There are other qualities a good CDN should have. It should start serving content quickly, and it should serve it with adequate speed (bandwidth). I’ll report on those measurements later.
Our Cloud Proximity Indicator is an aggregate measure, and is computing by averaging the distances to all monitoring stations.
|
Provider
|
Cloud Proximity (msec)
|
|
Akamai (MySpace)
|
6
|
|
Amazon Cloudfront
|
43
|
|
Mosso
|
49
|
|
GAE
|
61
|
|
CNN.com
|
66
|
|
SimpleCDN
|
94
|
|
Single host
|
127
|
Remarks and observations
• The round trip delay between Spain and New-Zealand (opposite on the globe) is around 290 milliseconds
• Akamai is really everywhere
• Google Applications Eengine, although fundamentally more powerful and still in beta, is pretty impressive. It is in the same league as most other CDNs.