Multithreaded Crystal initial thoughts

22

Now that Crystal 0.31.0 has been released! it’s probably a good idea to re-run benchmarks.

I’ve tried a hello world http server on MacOS with Crystal 0.31.0 and max I can get is about 48K req/s in single thread mode and 84K req/s in multithread mode with CRYSTAL_WORKERS=3 (other number of workers perform worse for me).

This is about 1.8 more throughput which is less that mentioned in first article https://crystal-lang.org/2019/09/06/parallelism-in-crystal.html where it goes from like 48K to about 120K for 3 workers as shown on charts. That’s about 2.5 more throughput.

UPDATE: Chart at https://crystal-lang.org/2019/09/06/parallelism-in-crystal.html it’s ~ 120K for CRYSTAL_WORKERS=4, but still, even CRYSTAL_WORKERS=2 seem to give better results than CRYSTAL_WORKERS=3 in my case.
I assume this has to do with either some commits landed after original article or my setup.

My env:

$ crystal --version
Crystal 0.31.0 (2019-09-24)

LLVM: 8.0.1
Default target: x86_64-apple-macosx

I’ve used http server from Crystal’s home page:

require "http/server"

server = HTTP::Server.new do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world, got #{context.request.path}!"
end

puts "Listening on http://127.0.0.1:8080"
server.listen(8080)

With

$ wrk -d10s -t2 -c128 --latency http://localhost:8080/foo
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