http://highscalability.com/blog/2011/6/27/tripadvisor-architecture-40m-visitors-200m-dynamic-page-view.html
request URL is parsed, content collected from various services, and then applied to a template
request routed to load balancer in front of cookie-based web server pool, pool can help for deployment, A/B testing, server are stateless
services are essentially large intelligent cache in front of database
DB: postgres, 6 DRDB pair for high availability
infrastructure to select code / template path based on request context
TripAdvisor architecture 2011/06
原文：http://www.cnblogs.com/qsort/p/5942699.html