Rubyonrails Mongoid 3 + Heroku (MongoHQ) 导致 Moped：：Errors：：OperationFailure

在从Mongoid 2升级后，使用Rails 3.x到Mongoid 3.x、 我的Heroku+MongoHQ设置停止工作.有趣的是，我的发展；测试框架和我的整个测试套件都通过得很好.

我怀疑问题出在我的mongoid身上.yml文件，但我试着搜索文档，谷歌&amp；stackoverflow，并使用了所有建议的格式，包括this:heroku mongohq and mongoid Mongo::ConnectionFailure或实际上this:https://gist.github.com/2900804

这就是我的蒙哥德.yml文件在try 了多项+After what Jason from MongoHQ suggested之后:

development:
  sessions:
    default:
      database: development
      hosts:
        - localhost:27017

test:
  sessions:
    default:
      database: test
      hosts:
        - localhost:27017

production:
  sessions:
    default:
      uri: <%= ENV['MONGOHQ_URL'] %>
      options:
        skip_version_check: true
        safe: true

(据我所知，它与上面链接中的基本相同，只是它使用了uri；我try 了另一种方法，将MONGOHQ_URL拆分为单独的字段，但没有帮助)

我try 将mongoid设置为3.0.0rc，并在我的文件中保留该版本为空.由于HTTPS证书或其他原因，使用github版本失败，所以我没有try 多次.

动作控制器说的是:

Moped::Errors::OperationFailure in Home#index

Showing /app/app/views/home/index.html.haml where line #2 raised:

The operation: #<Moped::Protocol::Command
  @length=68
  @request_id=4
  @response_to=0
  @op_code=2004
  @flags=[:slave_ok]
  @full_collection_name=".$cmd"
  @skip=0
  @limit=-1
  @selector={:count=>:posts, :query=>{}}
  @fields=nil>
failed with error "db assertion failure"

当我跑的时候

heroku run console 

我明白了:

irb(main):052:0> Location.create!
NoMethodError: undefined method `[]' for nil:NilClass
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:74:in `block in command'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:522:in `[]'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:522:in `block (3 levels) in flush'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:521:in `map'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:521:in `block (2 levels) in flush'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:113:in `ensure_connected'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:517:in `block in flush'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:532:in `logging'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:516:in `flush'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:505:in `process'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:70:in `command'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/node.rb:356:in `refresh'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/cluster.rb:101:in `block in refresh'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/cluster.rb:114:in `each'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/cluster.rb:114:in `refresh'
    from /app/vendor/bundle/ruby/1.9.1/gems/moped-1.1.1/lib/moped/cluster.rb:67:in `nodes'
... 15 levels...
    from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:405:in `__run_callback'
    from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:385:in `_run_save_callbacks'
    from /app/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.6/lib/active_support/callbacks.rb:81:in `run_callbacks'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/callbacks.rb:98:in `run_callbacks'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/persistence/insertion.rb:23:in `prepare'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/persistence/operations/insert.rb:26:in `persist'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/persistence.rb:50:in `insert'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/persistence.rb:251:in `block in create!'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/threaded/lifecycle.rb:173:in `_creating'
    from /app/vendor/bundle/ruby/1.9.1/gems/mongoid-3.0.1/lib/mongoid/persistence.rb:249:in `create!'
    from (irb):52
    from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/commands/console.rb:47:in `start'
    from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/commands/console.rb:8:in `start'
    from /app/vendor/bundle/ruby/1.9.1/gems/railties-3.2.6/lib/rails/commands.rb:41:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'irb(main):053:0> 

我想我已经用谷歌搜索了所有东西，浏览了多个github mongoid问题，多次阅读了文档...我的pip 都快用完了.

我下一步想试试什么？

UPDATE July 16th: this is what Heroku says when I git push heroku master (After doing what Jason from MongoHQ suggested):

git push heroku master
Counting objects: 7, done.
Delta compression using up to 16 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (4/4), 372 bytes, done.
Total 4 (delta 3), reused 0 (delta 0)

-----> Heroku receiving push
-----> Ruby/Rails app detected
-----> Installing dependencies using Bundler version 1.2.0.pre
       Running: bundle install --without development:test --path vendor/bundle --binstubs bin/ --deployment
       Using rake (0.9.2.2)
       Using i18n (0.6.0)
       Using multi_json (1.3.6)
       Using activesupport (3.2.6)
       Using builder (3.0.0)
            # ... shortened this #
       Using libv8 (3.3.10.4)
       Using moped (1.1.2)
       Using origin (1.0.4)
       Using mongoid (3.0.0.rc)
       Using omniauth (1.1.0)
       Using quimby (0.4.5)
       Using bundler (1.2.0.pre)
       Using rails (3.2.6)
       Using therubyracer (0.10.1)
       Using thin (1.3.1)
       Your bundle is complete! It was installed into ./vendor/bundle
       Cleaning up the bundler cache.
-----> Writing config/database.yml to read from DATABASE_URL
-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile
       Asset precompilation completed (31.24s)
-----> Rails plugin injection
       Injecting rails_log_stdout
       Injecting rails3_serve_static_assets
-----> Discovering process types
       Procfile declares types      -> (none)
       Default types for Ruby/Rails -> console, rake, web, worker
-----> Compiled slug size is 18.7MB
-----> Launching... done, v92
       http://xxxxx.herokuapp.com deployed to Heroku

To git@heroku.com:xxxxx.git
   b2d97xy..7b0aczy  master -> master

UPDATE 2 July 16th: did as Jason & MrKurt said (first forgot to run bundle update mongoid, but that didn't help either). Now the error changed, though:

NoMethodError in Home#index

Showing /app/app/views/home/index.html.haml where line #2 raised:

undefined method `[]' for nil:NilClass

Extracted source (around line #2):

    1: %h1 Most recent posts
    2: - if @posts.length > 0