Reading material

• http://en.wikipedia.org/wiki/Content_delivery_network
• Sec. 11.1.6 Caching and Replication, T&vS 1st Ed.
• Sec. 12.6.2 Replication for Web Hosting Systems, T&vS 2nd Ed.
• http://en.wikipedia.org/wiki/Coral_Content_Distribution_Network

1. Redirection with DNS

Experiment with DNS redirection using different lookup services and try to map the IP addresses to geographical locations.
Use at least three locations for sending your queries. One of the locations should be here in the department, for the other
two, select DNS lookup services on the web, such as http://network-tools.com/ (you need to find at least one additional
service).  Make lookups for the following domain names:

• www.google.com
• www.facebook.com
• www.apple.com
• cnn.com

2. Content Distribution with Coral

Familiarize yourself with CoralCDN: http://www.coralcdn.org/.

Create a large file (maybe 10-20 MB) in your own ~/public_html/ directory here at the department (or use
any other file of similar size). Perform the following retrievals and measure how long they take:

1. Retrieve the file directly from the server
2. Retrieve the file through Coral
3. Retrieve the file again through Coral
4. What can you see from the results? When would Coral be useful?

The Linux shell commands time and wget might prove helpful.