Target Application: Rails 2.3.x and Merb 1.3.x => Rails 3.1 or 3.2
Current: Apache 2.2 + Passenger 3.x + REE 1.8.7 without tcmalloc
Step1: Apache 2.2 + Unicorn + REE 1.8.7 with tcmalloc
Step2: Apache 2.2 + Unicorn + Ruby 1.9.3 with jemalloc
Step3: Nginx + Unicorn + Ruby 1.9.3 with jemalloc