From: "jeremyevans0 (Jeremy Evans) via ruby-core" Date: 2023-03-15T16:29:39+00:00 Subject: [ruby-core:112905] [Ruby master Bug#19412] Socket starts queueing and not responding after a certain amount of requests Issue #19412 has been updated by jeremyevans0 (Jeremy Evans). brodock (Gabriel Mazetto) wrote in #note-9: > @jeremyevans0 I've tested again in MacOS system provided ruby version: > > ``` > ruby --version > Could not locate Gemfile or .bundle/ directory > ruby 2.6.10p210 (2022-04-12 revision 67958) [universal.arm64e-darwin22] > ``` > > And that is consistent. It seems the problem is specific to MacOS, or worst when in MacOS. > > I've tried running the code above to make sure this is not apache/hey thing. In your pure Ruby hey-example, you have `CONCURRENCY = 512`, but your server has `BACKLOG = 50`. You would want `BACKLOG` to be higher than `CONCURRENCY`, otherwise I think at least some failures may be expected. Note that Ruby doesn't deal well with a high number of threads (and 512 threads would definitely be considered high in this case). For the client part, if you want to test concurrency, it would be better to fork/spawn separate processes and not use threads. I don't have any other ideas about what could be going wrong. You should try to see if either your client or server is leaking file descriptors. You could also try increasing the timeout. Unfortunately, not being able to reproduce the problem, I can only guess as to what the root cause might be. ---------------------------------------- Bug #19412: Socket starts queueing and not responding after a certain amount of requests https://bugs.ruby-lang.org/issues/19412#change-102423 * Author: brodock (Gabriel Mazetto) * Status: Open * Priority: Normal * ruby -v: ruby 3.2.1 (2023-02-08 revision 31819e82c8) [arm64-darwin22] * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- Here is a an example code: ```ruby require 'socket' PORT = 8080 BACKLOG = 50 LISTEN = '127.0.0.1' def handle_connection(connection, _addrinfo) request = connection.gets puts request connection.write "HTTP/1.1 200\r\n" connection.write "Content-Type: text/html\r\n" connection.write "\r\n" connection.write "Hello world! Current time is #{Time.now}" ensure connection.close end begin socket = Socket.new(:INET, :STREAM) socket.bind(Addrinfo.tcp(LISTEN, PORT)) socket.listen(BACKLOG) puts "Requested queue size: #{BACKLOG} bigger then limit: #{Socket::SOMAXCONN}" if BACKLOG > Socket::SOMAXCONN loop do listening, = IO.select([socket]) io, = listening connection, addrinfo = io.accept handle_connection(connection, addrinfo) end ensure socket.close end ``` This tries to simulate a TCP server that responds as if it was an HTTP server. The amount of requests it can sustain seems to depend on the OS. On a Linux machine running ubuntu 20.04 I get something around 7.6K to 7.8K until it stops responding. ``` $ uname -a Linux ... 5.17.5-x86_64-linode154 #1 SMP PREEMPT Mon May 2 15:07:22 EDT 2022 x86_64 x86_64 x86_64 GNU/Linux $ ab -n 20000 -c 50 http://127.0.0.1:8080/ This is ApacheBench, Version 2.3 <$Revision: 1843412 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ Licensed to The Apache Software Foundation, http://www.apache.org/ Benchmarking 127.0.0.1 (be patient) Completed 2000 requests Completed 4000 requests Completed 6000 requests apr_pollset_poll: The timeout specified has expired (70007) Total of 7883 requests completed ``` on MacOS Ventura I get around 16K: ``` $ uname -a Darwin ... 22.2.0 Darwin Kernel Version 22.2.0: Fri Nov 11 02:04:44 PST 2022; root:xnu-8792.61.2~4/RELEASE_ARM64_T8103 arm64 $ ab -n 20000 -c 50 http://127.0.0.1:8080/ This is ApacheBench, Version 2.3 <$Revision: 1901567 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ Licensed to The Apache Software Foundation, http://www.apache.org/ Benchmarking 127.0.0.1 (be patient) Completed 2000 requests Completed 4000 requests Completed 6000 requests Completed 8000 requests Completed 10000 requests Completed 12000 requests Completed 14000 requests Completed 16000 requests apr_socket_recv: Operation timed out (60) Total of 16375 requests completed ``` in both cases when that limit reaches, if I abort the program (CTRL-C) and try to run it again it takes a while until the port is released: ``` ... GET / HTTP/1.0 GET / HTTP/1.0 GET / HTTP/1.0 ^Csocketserver.rb:29:in `select': Interrupt from socketserver.rb:29:in `block in
' from socketserver.rb:28:in `loop' from socketserver.rb:28:in `
' $ ruby socketserver.rb socketserver.rb:23:in `bind': Address already in use - bind(2) for 127.0.0.1:8080 (Errno::EADDRINUSE) from socketserver.rb:23:in `
' ``` After killing the process it seems no process is holding the port: ``` lsof -wni tcp:8080 ``` Running the command above does not return anything (it does when the program is still running). I think we may be failing to release something when interacting with the Socket on syscalls/kernel level and we endup filling up some queue/buffer that eventually gets freed. -- https://bugs.ruby-lang.org/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/