Issue #18940 has been updated by jhawthorn (John Hawthorn). Status changed from Assigned to Closed This doesn't reproduce on my machine on 3.5dev, and there have been a number of improvements to Ractors likely to have solved this. Please reopen if that's not the case :) ---------------------------------------- Bug #18940: Ruby Ractor fails with IOError when handling higher concurrency https://bugs.ruby-lang.org/issues/18940#change-113932 * Author: brodock (Gabriel Mazetto) * Status: Closed * Assignee: ractor * ruby -v: ruby 3.2.0dev (2022-07-26T16:40:03Z master 3b1ed03d8c) [arm64-darwin21] * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN ---------------------------------------- Reproduction server: ``` require 'socket' # Set based on CPU count CONCURRENCY = 8 server = TCPServer.new(8080) workers = CONCURRENCY.times.map do Ractor.new do loop do # receive TCPSocket session = Ractor.recv request = session.gets puts request session.print "HTTP/1.1 200\r\n" session.print "Content-Type: text/html\r\n" session.print "\r\n" session.print "Hello world! Current time is #{Time.now}" session.close end end end loop do conn, _ = server.accept # pass TCPSocket to one of the workers workers.sample.send(conn, move: true) end ``` run apache benchmark against code above: ``` ab -n 20000 -c 20 http://localhost:8080/ ``` or run using hey (https://github.com/rakyll/hey): ``` hey -n 20000 -c 20 http://localhost:8080/ ``` you should see something like this on the benchmark tool side: ``` Summary: Total: 32.9538 secs Slowest: 2.6317 secs Fastest: 0.0002 secs Average: 0.0331 secs Requests/sec: 606.9098 Response time histogram: 0.000 [1] | 0.263 [16968] |■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■ 0.527 [1740] |■■■■ 0.790 [0] | 1.053 [0] | 1.316 [0] | 1.579 [0] | 1.842 [0] | 2.105 [20] | 2.369 [0] | 2.632 [6] | Latency distribution: 10% in 0.0008 secs 25% in 0.0010 secs 50% in 0.0012 secs 75% in 0.0016 secs 90% in 0.0075 secs 95% in 0.3101 secs 99% in 0.3175 secs Details (average, fastest, slowest): DNS+dialup: 0.0322 secs, 0.0002 secs, 2.6317 secs DNS-lookup: 0.0006 secs, 0.0000 secs, 0.0127 secs req write: 0.0001 secs, 0.0000 secs, 0.0095 secs resp wait: 0.0007 secs, 0.0000 secs, 0.0140 secs resp read: 0.0001 secs, 0.0000 secs, 0.0088 secs Status code distribution: [200] 18735 responses Error distribution: [1231] Get "http://localhost:8080/": dial tcp [::1]:8080: connect: connection refused [16] Get "http://localhost:8080/": dial tcp [::1]:8080: connect: connection reset by peer [1] Get "http://localhost:8080/": net/http: HTTP/1.x transport connection broken: unexpected EOF [1] Get "http://localhost:8080/": read tcp 127.0.0.1:57078->127.0.0.1:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57054->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57058->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57059->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57062->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57067->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57068->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57069->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57070->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57071->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57072->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57075->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57076->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57087->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57088->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57089->[::1]:8080: read: connection reset by peer [1] Get "http://localhost:8080/": read tcp [::1]:57090->[::1]:8080: read: connection reset by peer ``` and this on the ruby process: ``` ... GET / HTTP/1.1 GET / HTTP/1.1 #<Thread:0x0000000100fbf6e8 run> terminated with exception (report_on_exception is true): ractor.rb:21:in `write': GET / HTTP/1.1 uninitialized stream (IOError) from ractor.rb:21:in `print' from ractor.rb:21:in `block (3 levels) in <main>' from ractor.rb:11:in `loop' from ractor.rb:11:in `block (2 levels) in <main>' GET / HTTP/1.1 GET / HTTP/1.1 ``` -- https://bugs.ruby-lang.org/