ruby-on-rails - Postgres + Heroku SSL SYSCALL 错误

Question

有时我托管在 Heroku 上的 Rails 应用程序会宕机，我不确定发生了什么。有时可能会事先发生许多请求超时错误。然后我得到这个错误: 有谁知道可能会发生什么或者我可以如何进一步调查这个问题？

NilClass# (PG::Error) "SSL SYSCALL error: EOF detected\n"


/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:294:in `exec'/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:294:in `dealloc'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:278:in `block in clear'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:277:in `each_value'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:277:in `clear'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:339:in `clear_cache!'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/postgresql_adapter.rb:352:in `reconnect!'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract_adapter.rb:219:in `verify!'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:333:in `block in checkout_and_verify'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:403:in `_run__2596940609290925681__checkout__3309272650293367200__callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:405:in `__run_callback'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:385:in `_run_checkout_callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:81:in `run_callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:332:in `checkout_and_verify'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:253:in `block (2 levels) in checkout'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
/usr/local/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
/usr/local/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/query_cache.rb:61:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.12/lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:405:in `_run__1965518221808316025__call__3309272650293367200__callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:405:in `__run_callback'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/callbacks.rb:81:in `run_callbacks'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/rack/logger.rb:32:in `call_app'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/rack/logger.rb:16:in `block in call'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/tagged_logging.rb:22:in `tagged'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/rack/logger.rb:16:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/request_id.rb:22:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/methodoverride.rb:21:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/runtime.rb:17:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.12/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/lock.rb:15:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/actionpack-3.2.12/lib/action_dispatch/middleware/static.rb:62:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:136:in `forward'
/app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:245:in `fetch'
/app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:185:in `lookup'
/app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:66:in `call!'
/app/vendor/bundle/ruby/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:51:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/engine.rb:479:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/application.rb:223:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/railtie/configurable.rb:30:in `method_missing'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/static.rb:119:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/content_length.rb:14:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/rack/log_tailer.rb:17:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/connection.rb:81:in `block in pre_process'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/connection.rb:79:in `catch'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/connection.rb:79:in `pre_process'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/connection.rb:54:in `process'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/connection.rb:39:in `receive_data'
/app/vendor/bundle/ruby/1.9.1/gems/eventmachine-1.0.0/lib/eventmachine.rb:187:in `run_machine'
/app/vendor/bundle/ruby/1.9.1/gems/eventmachine-1.0.0/lib/eventmachine.rb:187:in `run'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/backends/base.rb:63:in `start'
/app/vendor/bundle/ruby/1.9.1/gems/thin-1.5.0/lib/thin/server.rb:159:in `start'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/handler/thin.rb:13:in `run'
/app/vendor/bundle/ruby/1.9.1/gems/rack-1.4.5/lib/rack/server.rb:268:in `start'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/commands/server.rb:70:in `start'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/commands.rb:55:in `block in <top (required)>'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/commands.rb:50:in `tap'
/app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.12/lib/rails/commands.rb:50:in `<top (required)>'
script/rails:6:in `require'
script/rails:6:in `<main>'

Answer 1

以下链接可能是一个起点:

https://devcenter.heroku.com/articles/postgres-logs-errors#pgerror-ssl-syscall-error-eof-detected

特别是以下摘录:

These errors indicate a client side violation of the wire protocol. This happens for one of two reasons:

• The Postgres connection is shared between more than one process or thread. Typical offenders are Resque workers or Unicorn. Be sure to correctly establish the PG connection after the fork or thread has initialized to resolve this issue.

• Abrupt client (application side) disconnections. This can happen for many reasons, from your app crashing, to transient network availability. When your app tries to issue a query again against postgres, the connection is just gone, leading to a crash. When Heroku detects a crash, we migrate kill that dyno and start a new one, which re-establishes the connection.

我看到了一个类似的问题，虽然上面的内容很有帮助，但我希望有一种方法可以真正解决这个问题(如果您不能阻止客户端使服务器崩溃，这似乎不是最佳选择)。我已经向 Heroku 提交了一张票，所以如果我发现任何进一步的问题，我会提出建议......

更新:这是另一个可能相关的链接:https://github.com/rails/rails/issues/9421 .