Ruby Performance Optimization

Do Out-of-Band Garbage Collection

Despite all our optimization efforts, GC will continue to take a substantial part of execution time. So what do we do if we can’t reduce GC time? We force GC when our application isn’t doing anything. That approach is called Out-of-Band Garbage Collection (OOBGC).

No OOBGC Necessary for Ruby Version 2.2 and Higher

Why is it important to reduce GC time or do GC while your code is idle? Because your application must stop and wait for (the marking phase of) GC to finish. However, with Ruby 2.2 and its incremental GC, the “stop the world” time is much less than before. So chances are you’ll never need OOBGC if you use Ruby 2.2 and later. You’ll see why in the next chapter.

Idle time is something that we usually ...