Resque 工作人员间歇性 "Moped::Protocol::Command failed with error nil" 错误
intermittent "Moped::Protocol::Command failed with error nil" errors in Resque workers
我正在使用 Rails 3.2、Mongoid 3.1.7、Moped 1.5.3 和 Resque 1.24.1
我的 Resque worker 中反复出现 "Moped::Protocol::Command failed with error nil" [1] 个错误。
Moped repo 中的 This issue, and this one 让我认为这可能是由于 Resque 分叉，但它们都是关于比我使用的旧版本的 Moped，而且我一直无法找到任何特定于配置 Resque 以与 Mongoid 很好地协同工作的特定信息。
如何解决我的 Resque worker 中的错误？
[1] 完整错误：
Exception: Moped::Errors::OperationFailure
Error: The operation: #<Moped::Protocol::Command @length=58 @request_id=3 @response_to=0 @op_code=2004 @flags=[] @full_collection_name="admin.$cmd" @skip=0 @limit=-1 @selector={:ismaster=>1} @fields=nil> failed with error nil
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:99:in `block in command'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:600:in `[]'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:600:in `block (3 levels) in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:599:in `map'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:599:in `block (2 levels) in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:150:in `ensure_connected'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:595:in `block in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:610:in `logging'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:594:in `flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:583:in `process'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:92:in `command'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:409:in `refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:171:in `block in refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:185:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:185:in `refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:135:in `nodes'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:206:in `with_primary'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/session/context.rb:108:in `with_node'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cursor.rb:137:in `load_docs'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cursor.rb:25:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/query.rb:76:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/query.rb:76:in `each'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:423:in `entries'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:423:in `check_existence'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:146:in `exists?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual.rb:19:in `exists?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:273:in `validate_root'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:52:in `block in validate_each'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/queryable.rb:23:in `with_query'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:46:in `validate_each'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:153:in `block in validate'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:150:in `each'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:150:in `validate'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:310:in `_callback_before_265'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:418:in `_run__123721054543109017__validate__3207805434451540367__callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:405:in `__run_callback'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:385:in `_run_validate_callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:81:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/callbacks.rb:130:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations.rb:228:in `run_validations!'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations/callbacks.rb:53:in `block in run_validations!'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:403:in `_run__123721054543109017__validation__3207805434451540367__callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:405:in `__run_callback'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:385:in `_run_validation_callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:81:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/callbacks.rb:130:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations/callbacks.rb:53:in `run_validations!'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations.rb:195:in `valid?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations.rb:84:in `valid?'
/releases/20160315172839/app/performers/garmin_receive_push.rb:11:in `block in perform'
/releases/20160315172839/app/performers/garmin_receive_push.rb:9:in `map'
/releases/20160315172839/app/performers/garmin_receive_push.rb:9:in `perform'
这似乎奏效了。在过去的 18 小时内，我的 Resque worker 昨天出现了 30 多个错误，现在为 0 个。
添加到我的 Resque 配置中：
Resque.before_fork do
::Mongoid.default_session.disconnect
end
对于这里到底出了什么问题，我没有一个非常连贯的描述。 Resque workers fork 一个子进程，然后子进程处理作业，所以我目前的操作假设是，这类似于链接问题中描述的 Unicorn 和 Passenger fork 的问题。
我正在使用 Rails 3.2、Mongoid 3.1.7、Moped 1.5.3 和 Resque 1.24.1
我的 Resque worker 中反复出现 "Moped::Protocol::Command failed with error nil" [1] 个错误。
Moped repo 中的This issue, and this one 让我认为这可能是由于 Resque 分叉，但它们都是关于比我使用的旧版本的 Moped，而且我一直无法找到任何特定于配置 Resque 以与 Mongoid 很好地协同工作的特定信息。
如何解决我的 Resque worker 中的错误？
[1] 完整错误：
Exception: Moped::Errors::OperationFailure
Error: The operation: #<Moped::Protocol::Command @length=58 @request_id=3 @response_to=0 @op_code=2004 @flags=[] @full_collection_name="admin.$cmd" @skip=0 @limit=-1 @selector={:ismaster=>1} @fields=nil> failed with error nil
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:99:in `block in command'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:600:in `[]'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:600:in `block (3 levels) in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:599:in `map'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:599:in `block (2 levels) in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:150:in `ensure_connected'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:595:in `block in flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:610:in `logging'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:594:in `flush'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:583:in `process'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:92:in `command'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/node.rb:409:in `refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:171:in `block in refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:185:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:185:in `refresh'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:135:in `nodes'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cluster.rb:206:in `with_primary'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/session/context.rb:108:in `with_node'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cursor.rb:137:in `load_docs'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/cursor.rb:25:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/query.rb:76:in `each'
/shared/bundle/ruby/2.2.0/gems/moped-1.5.3/lib/moped/query.rb:76:in `each'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:423:in `entries'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:423:in `check_existence'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual/mongo.rb:146:in `exists?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/contextual.rb:19:in `exists?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:273:in `validate_root'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:52:in `block in validate_each'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/queryable.rb:23:in `with_query'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations/uniqueness.rb:46:in `validate_each'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:153:in `block in validate'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:150:in `each'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validator.rb:150:in `validate'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:310:in `_callback_before_265'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:418:in `_run__123721054543109017__validate__3207805434451540367__callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:405:in `__run_callback'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:385:in `_run_validate_callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:81:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/callbacks.rb:130:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations.rb:228:in `run_validations!'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations/callbacks.rb:53:in `block in run_validations!'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:403:in `_run__123721054543109017__validation__3207805434451540367__callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:405:in `__run_callback'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:385:in `_run_validation_callbacks'
/shared/bundle/ruby/2.2.0/gems/activesupport-3.2.22/lib/active_support/callbacks.rb:81:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/callbacks.rb:130:in `run_callbacks'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations/callbacks.rb:53:in `run_validations!'
/shared/bundle/ruby/2.2.0/gems/activemodel-3.2.22/lib/active_model/validations.rb:195:in `valid?'
/shared/bundle/ruby/2.2.0/gems/mongoid-3.1.7/lib/mongoid/validations.rb:84:in `valid?'
/releases/20160315172839/app/performers/garmin_receive_push.rb:11:in `block in perform'
/releases/20160315172839/app/performers/garmin_receive_push.rb:9:in `map'
/releases/20160315172839/app/performers/garmin_receive_push.rb:9:in `perform'
这似乎奏效了。在过去的 18 小时内，我的 Resque worker 昨天出现了 30 多个错误，现在为 0 个。
添加到我的 Resque 配置中：
Resque.before_fork do
::Mongoid.default_session.disconnect
end
对于这里到底出了什么问题，我没有一个非常连贯的描述。 Resque workers fork 一个子进程，然后子进程处理作业，所以我目前的操作假设是，这类似于链接问题中描述的 Unicorn 和 Passenger fork 的问题。