References and tools for Memory Consumption in Rails

It's not often that I need these, but when there's a Memory Consumption issue in a Rails application, these references and tools definitely come in handy:

Rails 3 References and Tools

• Ruby on Rails Guides: Performance Testing Rails Applications
• Debugging Ruby (Aman Gupta presentation at Rails Conf 2011)
• Rack-Perftools Profiler
• Rack-Bug (Rails 3 branch)

Some Older References and Tools

• That's not a Memory Leak, it's Bloat (Engine Yard Blog Post)
• Bleak House
• Episode #20 - On The Edge - Part 2\
• MemoryLogic
• Oink
• Rack-Bug