Actioncable：プーマがこのエラーをキャッチしました：5.000秒以内にプールから接続を取得できませんでした

Question

ローカル（C9.io、まだライブを試していない）で作業しているときにこの特定のエラーが表示されます。これは、多くのユーザーがチャットの会話を使用しているときに発生します。

また、私はプラットフォームでしばらくの間働いていることに気付きました... CPUレベルのスカイロケット。何が原因でしょうか？

Puma caught this error: could not obtain a connection from the pool within 5.000 seconds (waited 5.022 seconds); all pooled connections were in use (ActiveRecord::ConnectionTimeoutError) 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:202:in `block in wait_poll' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:193:in `loop' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:193:in `wait_poll' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:154:in `internal_poll' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:278:in `internal_poll' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:148:in `block in poll' 
/usr/local/rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/monitor.rb:214:in `mon_synchronize' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:158:in `synchronize' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:148:in `poll' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:709:in `acquire_connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:501:in `checkout' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:364:in `connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:875:in `retrieve_connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_handling.rb:128:in `retrieve_connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/connection_handling.rb:91:in `connection' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activerecord-5.0.0.1/lib/active_record/query_cache.rb:27:in `run' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/execution_wrapper.rb:39:in `block in register_hook' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:396:in `instance_exec' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:396:in `block in make_lambda' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:169:in `block (2 levels) in halting' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:547:in `block (2 levels) in default_terminator' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:546:in `catch' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:546:in `block in default_terminator' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:170:in `block in halting' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:454:in `block in call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:454:in `each' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:454:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:101:in `__run_callbacks__' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:750:in `_run_run_callbacks' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/callbacks.rb:90:in `run_callbacks' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/execution_wrapper.rb:99:in `run!' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/execution_wrapper.rb:61:in `block in run!' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/execution_wrapper.rb:58:in `tap' 
/usr/local/rvm/gems/ruby-2.3.0/gems/activesupport-5.0.0.1/lib/active_support/execution_wrapper.rb:58:in `run!' 
/usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.1/lib/action_dispatch/middleware/executor.rb:10:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.1/lib/action_dispatch/middleware/static.rb:136:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/rack-cors-0.4.0/lib/rack/cors.rb:80:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/rack-2.0.1/lib/rack/sendfile.rb:111:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/railties-5.0.0.1/lib/rails/engine.rb:522:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/rack-cors-0.4.0/lib/rack/cors.rb:80:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/puma-3.6.0/lib/puma/configuration.rb:225:in `call' 
/usr/local/rvm/gems/ruby-2.3.0/gems/puma-3.6.0/lib/puma/server.rb:578:in `handle_request' 
/usr/local/rvm/gems/ruby-2.3.0/gems/puma-3.6.0/lib/puma/server.rb:415:in `process_client' 
/usr/local/rvm/gems/ruby-2.3.0/gems/puma-3.6.0/lib/puma/server.rb:275:in `block in run' 
/usr/local/rvm/gems/ruby-2.3.0/gems/puma-3.6.0/lib/puma/thread_pool.rb:116:in `block in spawn_thread' 

Answer 1

これはスケーリングの問題のようです。 this stackoverflow postで提案されているActiveRecordプールサイズを増やしてみてください。

CPU使用量については、コードを見ずに判断する方法はほとんどありません。それでも、それは困難になるでしょう。 NewRelicのようなツールを監視して、CPU集約部分がどこにあるかを確認してください。