我有50个sidekiq线程在网上爬行，几周前，这些线程在运行了大约20分钟后开始挂起。当我进行回溯转储时，大多数线程都被困在net/httpinitialize:上
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:879:in `initialize'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:879:in `open'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:879:in `block in connect'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:76:in `timeout'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:878:in `connect'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:863:in `do_start'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/net/http.rb:858:in `start'
/app/vendor/bundle/ruby/2.1.0/gems/net-http-persistent-2.9.4/lib/net/http/persistent.rb:700:in `start'
/app/vendor/bundle/ruby/2.1.0/gems/net-http-persistent-2.9.4/lib/net/http/persistent.rb:631:in `connection_for'
/app/vendor/bundle/ruby/2.1.0/gems/net-http-persistent-2.9.4/lib/net/http/persistent.rb:994:in `request'
/app/vendor/bundle/ruby/2.1.0/gems/mechanize-2.7.2/lib/mechanize/http/agent.rb:257:in `fetch'
/app/vendor/bundle/ruby/2.1.0/gems/mechanize-2.7.2/lib/mechanize/http/agent.rb:974:in `response_redirect'
/app/vendor/bundle/ruby/2.1.0/gems/mechanize-2.7.2/lib/mechanize/http/agent.rb:298:in `fetch'
/app/vendor/bundle/ruby/2.1.0/gems/mechanize-2.7.2/lib/mechanize.rb:432:in `get'
/app/app/workers/crawl_page.rb:24:in `block in perform'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:91:in `block in timeout'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:35:in `block in catch'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:35:in `catch'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:35:in `catch'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:106:in `timeout'
我不认为sidekiq会被困在net/http上，因为我已经在超时中完成了整个调用：Timeout::timeout(APP_CONFIG['crawl_page_timeout']) { @page = agent.get(url) }
但后来我开始阅读一些关于ruby的Timeout是如何不线程安全的旧帖子：http://blog.headius.com/2008/02/rubys-threadraise-threadkill-timeoutrb.html
ruby的Timeout仍然不是线程安全的吗？
我知道很多人用Ruby写爬虫。如果Timeout不是线程安全的，那么编写爬网程序的人是如何处理net/http被卡住的问题的？
更新：
我已经切换到HTTPClient（它特别说它的线程安全）来取代mechanize。我们似乎仍然被困在初始化线程上。同样，这可能是由于ruby'ss超时无法正常工作，也可能是sidekiq问题。以下是最近挂起的sidekiq线程的堆栈跟踪：
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:805:in `initialize'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:805:in `new'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:805:in `create_socket'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:752:in `block in connect'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:91:in `block in timeout'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:101:in `call'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:101:in `timeout'
/app/vendor/ruby-2.1.2/lib/ruby/2.1.0/timeout.rb:127:in `timeout'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:751:in `connect'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:609:in `query'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient/session.rb:164:in `query'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:1087:in `do_get_block'
/app/vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.9.2.239/lib/new_relic/agent/instrumentation/httpclient.rb:34:in `block in do_get_block_with_newrelic'
/app/vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.9.2.239/lib/new_relic/agent/cross_app_tracing.rb:43:in `tl_trace_http_request'
/app/vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.9.2.239/lib/new_relic/agent/instrumentation/httpclient.rb:33:in `do_get_block_with_newrelic'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:891:in `block in do_request'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:985:in `protect_keep_alive_disconnected'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:890:in `do_request'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:963:in `follow_redirect'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:776:in `request'
/app/vendor/bundle/ruby/2.1.0/gems/httpclient-2.4.0/lib/httpclient.rb:677:in `get'
/app/app/ohm_models/queued_page.rb:20:in `run_crawl'
正确，在Ruby代码中使用Timeout仍然是不安全的，除非您确切地了解该块中发生的事情（包括任何C代码可能正在做的事情）。因此，我个人观察到连接池中发生了灾难性的事情。
您可能能够挽救错误并重试，但如果您运气不好，您的进程可能会被卡住，需要重新启动。
如果你分叉创建新的进程，如果它们运行时间长，你可以安全地杀死它们（或者使用timeout(1)，因为它们没有任何方法破坏你的父进程。
我知道很多人用Ruby写爬虫。如果Timeout不是线程安全的，那么编写爬网程序的人是如何处理net/http被卡住的问题的？
你有一个具体的例子吗？