If you asked me what “a few kb” times “hundreds of thousands” is, I’d have characterized it as “more than a few hundreds of thousands of kb”, not necessarily “g

If you asked me what “a few kb” times “hundreds of thousands” is, I’d have characterized it as “more than a few hundreds of thousands of kb”, not necessarily “gigabytes,” and that doesn’t sound impractical at all. My JVM heaps are usually 16GB. And go actually does a pretty good job of scheduling hundreds of thousands of threads. 6 months ago I did some fairly abusive high-thread-count experiments solving problems in silly ways that required all N goroutines to participate and I didn’t see much perf falloff on my laptop until I got 1.5-2 million goroutines.