rufus + puma + heroku警告

Question

我在heroku上运行了一个rails应用，我有两个web dynos。我怎么才能移除！警告:在应用程序启动中检测到1个启动的线程:警告？

我的puma.rb文件：

workers Integer(ENV['WEB_CONCURRENCY'] || 2)
threads_count = Integer(ENV['RAILS_MAX_THREADS'] || 5)
threads threads_count, threads_count

preload_app!

rackup      DefaultRackup
port        ENV['PORT']     || 3000
environment ENV['RACK_ENV'] || 'development'

on_worker_boot do |worker_number| 
  # Worker specific setup for Rails 4.1+
  # See: https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server#on-worker-boot
  ActiveRecord::Base.establish_connection
end

日志：

2016-09-03T14:21:24.742960+00:00 app[web.1]: [3] * Listening on tcp://0.0.0.0:53786
2016-09-03T14:21:24.743135+00:00 app[web.1]: [3] ! WARNING: Detected 1 Thread(s) started in app boot:
2016-09-03T14:21:24.743181+00:00 app[web.1]: [3] ! #<Thread:0x007f382b59fca8@/app/vendor/bundle/ruby/2.2.0/gems/rufus-scheduler-3.2.2/lib/rufus/scheduler.rb:563 sleep> - /app/vendor/bundle/ruby/2.2.0/gems/rufus-scheduler-3.2.2/lib/rufus/scheduler.rb:571:in `sleep'
2016-09-03T14:21:24.743257+00:00 app[web.1]: [3] Use Ctrl-C to stop
2016-09-03T14:21:24.754941+00:00 app[web.1]: [3] - Worker 0 (pid: 7) booted, phase: 0
2016-09-03T14:21:24.756269+00:00 app[web.1]: [3] - Worker 1 (pid: 20) booted, phase: 0
2016-09-03T14:21:25.525174+00:00 app[web.2]: ** [NewRelic][2016-09-03 14:21:25 +0000 web.2 (18)] INFO : Doing deferred dependency-detection before Rack startup

Answer 1

这很简单。停止使用rufus-scheduler。它正在使用线程，这就是导致您警告的原因。

请看：

2016-09-03T14:21:24.743181+00:00 app[web.1]: [3] ! 
<Thread:0x007f382b59fca8@
/app/vendor/bundle/ruby/2.2.0/gems/rufus-scheduler-3.2.2/lib/rufus/scheduler.rb:563
sleep> -
/app/vendor/bundle/ruby/2.2.0/gems/rufus-scheduler-3.2.2/lib/rufus/scheduler.rb:571
:in `sleep'

Rufus-scheduler显然是导致警告的原因。

Cf https://github.com/jmettraux/rufus-scheduler/issues/213

现在有了另一种方式来看待这件事:警告不是由rufus-scheduler发出的，而是由彪马发出的。可能有一种方法可以禁用警告，但对于了解彪马的人来说，这是一个问题。