Comment by amelius | Hacker News Reader

Comment by amelius | Hacker News Reader

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What I look for in a language first is how good the support is for concurrency, and especially if it has a good, modern concurrent garbage collector.

A quick search brought up this:

https://lisp-journey.gitlab.io/blog/pro-mailing-list-on-comm...

> This was primarily for the lack of good parallel, concurrent garbage collectors in Common Lisp implementations. The CL version of elPrep was actually still a tad faster than any of the C++, Go, or Java versions, but we had to work hard to avoid long GC pauses. elPrep allocates a lot of memory, and the pause time hurts a lot. We solved this by, basically, disabling the garbage collector, and reusing memory manually as much as possible, which turned the program into almost a manually memory-managed affair.

With respect to concurrency, after a lot of experience operating async Python services, the thing that I look for is a single, standard, ubiquitous concurrency model. One of the biggest pain points for operating Python systems is some transitive dependency making a synchronous I/O call and blocking the whole event loop, causing timeouts in unrelated endpoints and often bringing the whole system down (healthchecks start to fail because the endpoint is blocked and then the supervisor kills the whole process/pod/etc).

This doesn't happen in Go or (presumably) languages that run on Erlang's BEAM VM because there is no sync I/O (from the event loop's perspective, anyway).

Python has pre-emptive threading too! The GIL makes it all but useless for CPU-bound tasks, but it works fine for IO. Keep your health-check tasks in a non-IO thread and communicate with queues.

> What I look for in a language first is how good the support is for concurrency, and especially if it has a good, modern concurrent garbage collector.

...in which case you'll definitely not want to use Python either, and so are rather far out of place in this thread.

Python is a great language, but its design-mistakes regarding concurrency are exactly why I'm worried about that aspect when looking for a new language.

They didn't try Allegro CL's new parallel GC (see comments). Otherwise, yeah. It depends on one's use case, I guess.

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