独角兽下有大量线程

Steve Robinson 发表于 Dev

史蒂夫·罗宾逊

我正在调试我们的应用程序中的某些Posgtres连接泄漏。几天前，我们突然间不应该碰到100个连接-因为我们只有8个独角兽工作者和一个sidekiq进程（25个线程）。

我今天在看htop，看到我的独角兽工人产生了许多线程。例如：

我阅读正确吗？这不应该发生吧？如果这些是正在生成的线程，那么如何调试它呢？

谢谢！顺便说一句，我的另一个问题-（Postgres连接）调试独角兽postgres连接泄漏

编辑

我只是在这里遵循了一些技巧-http://varaneckas.com/blog/ruby-tracing-threads-unicorn/-当我从工作线程中打印堆栈跟踪时，这就是当有很多线程时得到的。

[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `pop'
[17176] /u/apps/eventstream_production/shared/bundle/ruby/2.2.0/gems/eventmachine-1.0.8/lib/eventmachine.rb:1057:in `block in spawn_threadpool'
[17176] ---
[17176] -------------------

这是我的unicorn.rb https://gist.github.com/steverob/b83e41bb49d78f9aa32f79136df5af5f，它在after_fork中为EventMachine生成了一个线程。

EventMachine的原因是-> https://github.com/keenlabs/keen-gem#asynchronous-publishing

这正常吗？线程不应该被杀死吗？是否还会导致不必要的数据库连接打开？谢谢

更新：我刚刚发现我正在使用使用EM的PubNub gem的旧版本，并且在pubnub.log文件中遇到了以下几行-

D, [2016-04-06T21:31:12.130123 #1573] DEBUG -- pubnub: Created event Pubnub::Publish
D, [2016-04-06T21:31:12.130144 #1573] DEBUG -- pubnub: Pubnub::SingleEvent#fire
D, [2016-04-06T21:31:12.130162 #1573] DEBUG -- pubnub: Pubnub::SingleEvent#fire | Adding event to async_events
D, [2016-04-06T21:31:12.130178 #1573] DEBUG -- pubnub: Pubnub::SingleEvent#fire | Starting railgun
D, [2016-04-06T21:31:12.130194 #1573] DEBUG -- pubnub: Pubnub::Client#start_event_machine | starting EM in new thread
D, [2016-04-06T21:31:12.130243 #1573] DEBUG -- pubnub: Pubnub::Client#start_event_machine | We aren't running on thin
D, [2016-04-06T21:31:12.130264 #1573] DEBUG -- pubnub: Pubnub::Client#start_event_machine | EM already running

波拉玛

因此，毕竟，在您的特定情况下，该行为似乎是正常的。

您提供（使用此方法获得）的独角兽线程堆栈跟踪指向EventMachine中的spawn_threadpool方法。调用其他代码时EventMachine.defer，将调用EventMachine中的此代码，该方法默认在第一次调用时生成20个线程的池。我EventMachine.defer在较旧版本的pubnubgem中找到了使用方法（例如here），但也可以在其他地方使用它。