Architecture of high-throughput, scalable web application

The points here are taken from this link (In Chinese).

A. Some notes from the book Building Scalable Web Sites (ISBN 0596102356, 2006, 352 pages).

1. Scale up a web application
   - vertically scale up: increase setting of single machine (memory, CPU).
   - horizontally scale up: add more machines
2. Redundancy
   - Back up: hot back up (online backup), cold back up (offline backup).
3. Load balancing
   - session/session-less load balancing
   - hardware/software load balancing
4. Cache

B. Article by Ni Haitao.

1. Use static html: convert dynamic content to static html.
2. Separate image/graphics server from application server.
3. Use database cluster instead of single database.
4. Use Cache. E.g.
   Apache - mod_proxy, squid; 
   Linux - memcached; 
   PHP - Pear cache, eaccelerator, Apc, XCache.
5. Use mirror site.
6. Load balancing.
   - hardware 4-layer exchange
   - software 4-layer exchange
   - 7-layer exchange