Issue #20782 has been updated by hsbt (Hiroshi SHIBATA). Status changed from Open to Assigned Assignee set to naruse (Yui NARUSE) ---------------------------------------- Feature #20782: Introduction of Happy Eyeballs Version 2 (RFC8305) in TCPSocket.new https://bugs.ruby-lang.org/issues/20782#change-110095 * Author: shioimm (Misaki Shioi) * Status: Assigned * Assignee: naruse (Yui NARUSE) ---------------------------------------- This is an implementation of Happy Eyeballs version 2 (RFC 8305) in `TCPSocket.new`. See https://github.com/ruby/ruby/pull/11653 ### Background Prior to this implementation, I implemented Happy Eyeballs Version 2 (HEv2) for `Socket.tcp` in https://github.com/ruby/ruby/pull/9374. HEv2 is an algorithm defined in [RFC 8305](https://datatracker.ietf.org/doc/html/rfc8305), aimed at improving network connectivity. For more details on the specific cases that HEv2 helps, please refer to https://bugs.ruby-lang.org/issues/20108. ### Proposal & Outcome This proposal implements the same HEv2 algorithm in `TCPSocket.new`. Since `TCPSocket.new` is used more widely than `Socket.tcp`, this change is expected to broaden the impact of HEv2's benefits. Like `Socket.tcp`, I have also added `fast_fallback` keyword argument to `TCPSocket.new`. This option is set to true by default, enabling the HEv2 functionality. However, users can explicitly set it to false to disable HEv2 and use the previous behavior of `TCPSocket.new`. It should be noted that HEv2 is enabled only in environments where pthreads are available. This specification follows the approach taken in https://bugs.ruby-lang.org/issues/19965, where name resolution can be interrupted. (In environments where pthreads are not available, the `fast_fallback` option is ignored.) ### Performance Below is the benchmark of 100 requests to `www.ruby-lang.org` with the fast_fallback option set to true and false, respectively. While there is a slight performance degradation when HEv2 is enabled, the degradation is smaller compared to that seen in `Socket.tcp` . ```ruby require 'socket' require 'benchmark' hostname = "www.ruby-lang.org" port = 80 n = 100 Benchmark.bmbm do |x| x.report("fast_fallback: true") do n.times { TCPSocket.new(hostname, port).close } end x.report("fast_fallback: false") do n.times { TCPSocket.new(hostname, port, fast_fallback: false).close } end end ``` ``` ~/s/build ❯❯❯ ../install/bin/ruby ../ruby/test.rb Rehearsal -------------------------------------------------------- fast_fallback: true 0.017588 0.097045 0.114633 ( 1.460664) fast_fallback: false 0.014033 0.078984 0.093017 ( 1.413951) ----------------------------------------------- total: 0.207650sec user system total real fast_fallback: true 0.020891 0.124054 0.144945 ( 1.473816) fast_fallback: false 0.018392 0.110852 0.129244 ( 1.466014) ``` -- https://bugs.ruby-lang.org/