Effective Testing With RSpec 3 · Build Ruby Apps With Confidence

This is the first book ever that consolidates all the Ruby performance optimization advice in one place. It’s your comprehensive guide to memory optimization, CPU optimization, garbage collector tuning, profiling, measurements, performance testing, and more.

You’ll go from performance rookie to expert. First, you’ll learn the best practices for writing Ruby code that’s easy not only on the CPU, but also on memory, and that doesn’t trigger the dreaded garbage collector. You’ll find out that garbage collection accounts for 80% of slowdowns, and often takes more than 50% of your program’s execution time. And you’ll discover the bottlenecks in Rails code and learn how selective attribute loading and preloading can mitigate the performance costs of ActiveRecord.

As you advance to Ruby performance expert, you’ll learn how to profile your code, how to make sense out of profiler reports, and how to make optimization decisions based on them. You’ll make sure slow code doesn’t creep back into your Rails application by writing performance tests, and you’ll learn the right way to benchmark Rails.

And finally, you’ll dive into the Ruby interpreter internals to really understand why garbage collection makes Ruby so slow, and how you can tune it up.