EC2でunicornを起動するとSegmentation faultになる

Question

前提・実現したいこと

EC2に既存のアプリをデプロイしている最中です。

unicornを起動する際にSegmentation faultになってしまいました。

実行したコマンド

[name@****** app名]$ bundle exec unicorn_rails -c config/unicorn.rb -E production -D

発生している問題・エラーメッセージ

# 起動に失敗しました。詳細については、stderrログを確認してください
master failed to start, check stderr log for details

# unicorn_stderr.log

INFO -- : Refreshing Gem list
/home/name/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/unicorn-5.8.0/lib/unicorn.rb:80: [BUG] Segmentation fault at 0x0000000000000000
ruby 3.0.0p0 (2020-12-25 revision *******) [x86_64-linux]

該当のソースコード

# unicorn.rb

worker_processes 1

pid File.expand_path('../../tmp/pids/unicorn.pid', __FILE__)

listen 3000

stderr_path File.expand_path('../../log/unicorn_stderr.log', __FILE__)
stdout_path File.expand_path('../../log/unicorn_stdout.log', __FILE__)

timeout 60

preload_app true

check_client_connection false

run_once = true

before_fork do |server, worker|
  defined?(ActiveRecord::Base) && ActiveRecord::Base.connection.disconnect!

  if run_once
    run_once = false
  end

  old_pid = "#{server.config[:pid]}.oldbin"
  if File.exist?(old_pid) && server.pid != old_pid
    begin
      sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
      Process.kill(sig, File.read(old_pid).to_i)
    rescue Errno::ENOENT, Errno::ESRCH => e
      logger.error e
    end
  end
end

after_fork do |_server, _worker|
  defined?(ActiveRecord::Base) && ActiveRecord::Base.establish_connection
end

下記がエラーメッセージに記載されていたファイルです。

# /home/name/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/unicorn-5.8.0/lib/unicorn.rb

# -*- encoding: binary -*-
require 'etc'
require 'stringio'
require 'kgio'
require 'raindrops'
require 'io/wait'

begin
  require 'rack'
rescue LoadError
  warn 'rack not available, functionality reduced'
end

# :stopdoc:
# Unicorn module containing all of the classes (include C extensions) for
# running a Unicorn web server.  It contains a minimalist HTTP server with just
# enough functionality to service web application requests fast as possible.
# :startdoc:

# unicorn exposes very little of an user-visible API and most of its
# internals are subject to change.  unicorn is designed to host Rack
# applications, so applications should be written against the Rack SPEC
# and not unicorn internals.
module Unicorn

  # Raised inside TeeInput when a client closes the socket inside the
  # application dispatch.  This is always raised with an empty backtrace
  # since there is nothing in the application stack that is responsible
  # for client shutdowns/disconnects.  This exception is visible to Rack
  # applications unless PrereadInput middleware is loaded.  This
  # is a subclass of the standard EOFError class and applications should
  # not rescue it explicitly, but rescue EOFError instead.
  ClientShutdown = Class.new(EOFError)

  # :stopdoc:

  # This returns a lambda to pass in as the app, this does not "build" the
  # app (which we defer based on the outcome of "preload_app" in the
  # Unicorn config).  The returned lambda will be called when it is
  # time to build the app.
  def self.builder(ru, op)
    # allow Configurator to parse cli switches embedded in the ru file
    op = Unicorn::Configurator::RACKUP.merge!(:file => ru, :optparse => op)
    if ru =~ /.ru$/ && !defined?(Rack::Builder)
      abort "rack and Rack::Builder must be available for processing #{ru}"
  end

    # always called after config file parsing, may be called after forking
    lambda do |_, server|
      inner_app = case ru
      when /.ru$/
        raw = File.read(ru)
        raw.sub!(/^__END__\n.*/, '')
        eval("Rack::Builder.new {(\n#{raw}\n)}.to_app", TOPLEVEL_BINDING, ru)
      else
        require ru
        Object.const_get(File.basename(ru, '.rb').capitalize)
      end

      if $DEBUG
        require 'pp'
        pp({ :inner_app => inner_app })
      end

      return inner_app unless server.default_middleware

      middleware = { # order matters
        ContentLength: nil,
        Chunked: nil,
        CommonLogger: [ $stderr ],
        ShowExceptions: nil,
        Lint: nil,
        TempfileReaper: nil,
      }

      # return value, matches rackup defaults based on env
      # Unicorn does not support persistent connections, but Rainbows!
      # and Zbatery both do.  Users accustomed to the Rack::Server default
      # middlewares will need ContentLength/Chunked middlewares.
      case ENV["RACK_ENV"]
      when "development"
      when "deployment"
        middleware.delete(:ShowExceptions)
        middleware.delete(:Lint)
      else
        return inner_app
      end
      Rack::Builder.new do
        middleware.each do |m, args|
          use(Rack.const_get(m), *args) if Rack.const_defined?(m)
        end
        run inner_app
      end.to_app
    end
  end

  # returns an array of strings representing TCP listen socket addresses
  # and Unix domain socket paths.  This is useful for use with
  # Raindrops::Middleware under Linux: https://yhbt.net/raindrops/
  def self.listener_names
    Unicorn::HttpServer::LISTENERS.map do |io|
      Unicorn::SocketHelper.sock_name(io)
    end + Unicorn::HttpServer::NEW_LISTENERS
  end

  def self.log_error(logger, prefix, exc)
    message = exc.message
    message = message.dump if /[[:cntrl:]]/ =~ message
    logger.error "#{prefix}: #{message} (#{exc.class})"
    exc.backtrace.each { |line| logger.error(line) }
  end
  F_SETPIPE_SZ = 1031 if RUBY_PLATFORM =~ /linux/

  def self.pipe # :nodoc:
    Kgio::Pipe.new.each do |io|
      io.close_on_exec = true  # remove this when we only support Ruby >= 2.0

      # shrink pipes to minimize impact on /proc/sys/fs/pipe-user-pages-soft
      # limits.
      if defined?(F_SETPIPE_SZ)
        begin
          io.fcntl(F_SETPIPE_SZ, Raindrops::PAGE_SIZE)
        rescue Errno::EINVAL
          # old kernel
        rescue Errno::EPERM
          # resizes fail if Linux is close to the pipe limit for the user
          # or if the user does not have permissions to resize
        end
      end
    end
  end
  # :startdoc:
end
# :enddoc:

%w(const socket_helper stream_input tee_input http_request configurator
   tmpio util http_response worker http_server).each do |s|
  require_relative "unicorn/#{s}"
end

試したこと

・ unicorn.rbのpidやstderr_pathのパスを変えてみる → 書き込みエラーが出るだけ

・ メモリの容量が足りない可能生から、EC2のインスタンスタイプをt2.microからt2.xlargeに変えてみる → 変化なし

・ unicornのバージョンを落としてみる → rubyが3.0.0のため落とせない

補足情報（FW/ツールのバージョンなど）

・ MacOS
・ Rails 6.1.0
・ Ruby 3.0.0
・ MySQL 8.0.23
・ unicron 5.8.0
・ nginx 1.18.0
・ Amazon Linux 2 AMI (HVM), SSD Volume Type
・ インスタンスタイプ t2.micro

下記のQiita1を参考にデプロイを進めました。

デプロイ参考記事

Answer 1

Rubyのバージョンを2.7.2、unicornのバージョンを5.4.1にダウングレードしたら動きました。

どうやらRubyの3.0.0にunicornが対応していないらしいです。