Question

我在heroku实例上使用了mongolab和monogid。

我可以在rails控制台中访问我的模型并创建它们。

然而 - 调用Model.first / Model.find_or_initialize_by会导致无限循环

MOPED: xx:29454 COMMAND      database=admin command={:ismaster=>1} runtime: 7.8211ms
  MOPED: xx:29454 QUERY        database=heroku_zl6cgccm 

collection=calculations selector={"$query"=>{}, "$orderby"=>{:_id=>1}} flags=[] limit=-1 skip=0 batch_size=nil fields=nil runtime: 1.6873ms
MOPED: xx:29454 QUERY        database=heroku_xx collection=calculations selector={"$query"=>{}, "$orderby"=>{:_id=>1}} flags=[] limit=-1 skip=0 batch_size=nil fields=nil runtime: 5.3479ms
  MOPED: xx:29454 QUERY        database=heroku_xx collection=calculations selector={"$query"=>{}, "$orderby"=>{:_id=>1}} flags=[] limit=-1 skip=0 batch_size=nil fields=nil runtime: 8.8738ms

一直到下来：

collection=calculations selector={"$query"=>{}, "$orderby"=>{:_id=>1}} flags=[] limit=-1 skip=0 batch_size=nil fields=nil runtime: 1544.7719ms
SystemStackError: stack level too deep
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/string.rb:79:in `to_bson_cstring'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/string.rb:63:in `to_bson_key'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/symbol.rb:58:in `to_bson_key'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/hash.rb:45:in `block (2 levels) in to_bson'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/hash.rb:43:in `each'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/hash.rb:43:in `block in to_bson'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/encodable.rb:57:in `encode_with_placeholder_and_null'
    from /app/vendor/bundle/ruby/2.2.0/gems/bson-3.2.4/lib/bson/hash.rb:42:in `to_bson'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/protocol/message.rb:173:in `serialize_selector'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/protocol/message.rb:325:in `serialize'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/connection.rb:171:in `block in write'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/connection.rb:169:in `each'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/connection.rb:169:in `write'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/authenticatable.rb:64:in `login'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/operation/read.rb:55:in `block (2 levels) in execute'
    from /app/vendor/bundle/ruby/2.2.0/gems/moped-2.0.7/lib/moped/node.rb:118:in `block in connection'
... 9285 levels...
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/query_cache.rb:190:in `first_with_cache'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual/mongo.rb:199:in `block (2 levels) in first'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual/mongo.rb:545:in `with_sorting'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual/mongo.rb:198:in `block in first'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual/mongo.rb:457:in `try_cache'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual/mongo.rb:197:in `first'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/contextual.rb:20:in `first'
    from /app/vendor/bundle/ruby/2.2.0/gems/mongoid-4.0.2/lib/mongoid/findable.rb:144:in `first'
    from (irb):10
    from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.4/lib/rails/commands/console.rb:110:in `start'
    from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.4/lib/rails/commands/console.rb:9:in `start'
    from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:68:in `console'
    from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from /app/vendor/bundle/ruby/2.2.0/gems/railties-4.2.4/lib/rails/commands.rb:17:in `<top (required)>'
    from /app/bin/rails:8:in `require'

这是我的mongoid.yml文件：

production:
 sessions:
   default:
     uri: <%= ENV['MONGOLAB_URI'] %>

     options:

       max_retries: 30
       retry_interval: 1
       timeout: 15

       refresh_interval: 10

Answer 1

我遇到了与MongoLab类似的问题，无法进行数据库查询，直到我的堆栈级别太深。我的客户想要一个免费的数据库，所以我坚持了12小时的故障排除。

我尝试了上面的所有内容，以及其他一些配置选项，然后偶然发现： https://devcenter.heroku.com/articles/mongolab

我忽略了一条线：“如果您使用的是MongoDB 3.0版（所有MongoLab Sandbox都是3.0版），您必须使用Mongoid 5.x.”。我已经运行了一个捆绑更新，所以我没想太多。

你应该进入你的gem文件并指定：

gem'mongoid'，'〜＆gt; 5.0'

我还必须删除我的mongoid.yml并重新开始

rails g mongoid：config

mongoid.yml将其嵌套更改为列出“客户端”而不是“会话”，这实际上会混淆Rails。

这就是为我解决的问题。

Answer 2

它看起来（从您的数据库用户名）我们都使用Hero的MongoHQ插件，他们的最低层数据库是分片的，我相信一旦它到达就需要一个简单的配置更改来帮助查询路由正确。

＃强制驱动程序集群以某种方式运行而不是自动运行＃discovering。可以是以下之一:: direct，：replica_set，：sharded。设置为：直接＃连接到副本集的隐藏成员时。 connect :: direct

http://docs.mongodb.org/ecosystem/tutorial/ruby-mongoid-tutorial/#anatomy-of-a-mongoid-config

我改为Mongo Compose插件没有分片，问题立即消失。

如果您想继续使用具有免费版本的MongoLab，请尝试修改配置，如：

options: 
  connect: :sharded

进一步阅读：http://docs.mongodb.org/manual/core/sharded-cluster-query-router/#broadcast-operations

Mongoid无限循环查询

2 个答案: