Web Technologies - Old Questions

12.  Discuss anti-overload techniques in webserver.

At any time web servers can be overloaded because of:

• Too much legitimate web traffic
• Thousands or even millions of clients hitting the web site in a short interval of time (DDoS) Distributed Denial of Service attacks
• Computer worms
• Millions of infected browsers and/or web servers
• limited on large web sites with very few resources (bandwidth, etc.)
• Client requests are served more slowly and the number of connections increases so much that server limits are reached
• Web servers required  urgent maintenance or upgrade
• Hardware Software failures

To partially overcome load limits and to prevent overload we can use techniques like:

• Managing network traffic by using: Firewalls, Block unwanted traffic
• HTTP traffic managers- redirect or rewrite requests having bad HTTP patterns
• Bandwidth management and traffic shaping
• Deploying web cache techniques
• Use different domains to serve different content (static and dynamic) by separate Web servers,
• Add more hardware resources
• Use many web servers

These technique to limit the load on websites are called anti-overload techniques in web server.