We recently shot three short videos showing a real world example, on a production application, where we demonstrated a methodology for load testing and determining bottlenecks which degrade performance as load increases.  In addition we also show the effects of applying what we call a "front caching" mechanism to dramatically improve performance.  The videos can be viewed here.

Front caching means a mechanism which sits before the web/application server after the firewall, router or clustering mechanism thereby reducing traffic/load on the whole back-end infrastructure.  Constructs such as memcached, sit in between the web/application servers and reduce load on the data tier.  We have also assisted several clients who use memcached but have found front caching mechanisms to be more effective overall.  More on this soon.