使用 Rails 3，从 Mongoid 2.x 升级到 Mongoid 3.x 后，我的 Heroku + MongoHQ 设置停止工作。有趣的是，我的开发和测试框架以及我的整个测试套件都通过了。

我怀疑问题出在我的 mongoid.yml 文件上，但我尝试搜索文档、google 和 stackoverflow，并使用了所有建议的格式，包括:heroku mongohq and mongoid Mongo::ConnectionFailure或者实际上是:https://gist.github.com/2900804

7 月 16 日更新:这是我的 mongoid.yml 文件在尝试了多种方法后的样子 + 在 MongoHQ 的 Jason 建议之后:

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

(据我了解，它与上面链接中的基本相同，除了它使用 uri；我尝试了另一种方式，也将 MONGOHQ_URL 拆分为单独的字段，但它没有帮助)

我尝试将 mongoid 设置为 3.0.0rc 并在我的 Gemfile 中将版本留空。由于HTTPS证书什么的，使用github版本失败，所以我没有费心尝试多次。

Action Controller 是这样说的:

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"

当我运行时

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内容，处理了多个 github mongoid 问题，多次阅读了文档......我的想法已经用完了。

接下来有什么想尝试的吗？

7 月 16 日更新:这是 Heroku 在我 git push heroku master 时所说的(按照 MongoHQ 的 Jason 的建议):

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

7 月 16 日 2 日更新:正如 Jason 和 MrKurt 所说的那样(首先忘记运行 bundle update mongoid，但这也无济于事)。不过，现在错误发生了变化:

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

最佳答案

您需要使用 Ruby 1.9.3。参见 Mongoid 文档 here和 Heroku 文档 here关于如何使用 1.9.3。

我也遇到了类似的错误，我将 gemfile 更改为包含 ruby '1.9.3' 并且一切都再次按预期工作。

编辑: @herb 指出您需要最新版本的 bundler 才能工作(gem install bundler --pre)。否则，您的 Gemfile 中的 ruby '1.9.3' 将不起作用。

关于ruby-on-rails - Mongoid 3 + Heroku (MongoHQ) 导致 Moped::Errors::OperationFailure，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11494134/