Scheduler

Go’s goroutine scheduler sits between your code and the OS. Understanding it is useful not because you’ll tune it (you rarely should) but because its behaviour explains a class of performance surprises and concurrency patterns that look odd until you see why they exist. ...

The first thing every Java developer learns about goroutines is that they’re cheap. Start a million of them, no problem. The mental model that follows from this — “goroutines are threads but lighter” — is close enough to be useful and wrong enough to cause confusion. Here’s the refined model. ...