ruby-on-rails - 在 heroku 上运行迁移的问题

Question

这是这篇文章的跟进 Rails, data structure and performance ，我试图在 Rails 上创建计数器缓存。为了不让它默认为 0，我还添加了将列更新为数据库中的现有计数值。

在开发中运行 rake db:migrate 工作正常，即使它需要几个小时才能运行。

但是使用 heroku 运行迁移会给我以下错误:

==  AddVotesCount: migrating ==================================================
-- add_column(:options, :votes_count, :integer, {:default=>0})
   -> 0.0196s
/Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `initialize': Operation timed out - connect(2) (Errno::ETIMEDOUT)
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `open'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `block in connect'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/timeout.rb:44:in `timeout'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/timeout.rb:87:in `timeout'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `connect'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:637:in `do_start'
    from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:626:in `start'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:172:in `transmit'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:64:in `execute'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:33:in `execute'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/resource.rb:51:in `get'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:554:in `process'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:532:in `get'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:290:in `read'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:311:in `each'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/command/run.rb:50:in `rake'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/command.rb:114:in `run'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/bin/heroku:14:in `<top (required)>'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/bin/heroku:19:in `load'
    from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/bin/heroku:19:in `<main>'

我已经尝试了一些不同的东西，但在这一点上似乎迷路了，任何帮助表示赞赏!奇怪的是，错误消息并不总是立即出现，有时需要 10/20 分钟，就像迁移正在运行一样。

谢谢

更新:这是我的迁移文件的内容:

class AddVotesCount < ActiveRecord::Migration
  def self.up
    add_column :options, :votes_count, :integer, :default => 0
    Option.all.each do |option|
       option.votes_count = option.votes.count
       option.save!
     end
  end

  def self.down
    remove_column :options, :votes_count
  end
end

更新 2:这适用于 heroku 的暂存环境......但不适用于生产

经过一些修改，现在的迁移代码是:

def self.up
    add_column :options, :votes_count, :integer, :default => 0
    Option.reset_column_information
    Option.find_each do |option|
      Option.reset_counters option.id, :votes
    end

错误是:

==  AddVotesCount: migrating ==================================================
-- add_column(:options, :votes_count, :integer, {:default=>0})
-> 0.0224s
/Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `initialize': getaddrinfo: nodename nor servname provided, or not known (SocketError)
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `open'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `block in connect'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/timeout.rb:44:in `timeout'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/timeout.rb:87:in `timeout'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:644:in `connect'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:637:in `do_start'
        from /Users/ebellity/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/net/http.rb:626:in `start'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:172:in `transmit'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:64:in `execute'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/request.rb:33:in `execute'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/rest-client-1.6.7/lib/restclient/resource.rb:51:in `get'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:554:in `process'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:532:in `get'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:290:in `read'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/client.rb:311:in `each'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/command/run.rb:50:in `rake'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/lib/heroku/command.rb:114:in `run'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/gems/heroku-2.8.4/bin/heroku:14:in `<top (required)>'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/bin/heroku:19:in `load'
        from /Users/ebellity/.rvm/gems/ruby-1.9.2-p136/bin/heroku:19:in `<main>'

Answer 1

对于那些可能遇到同样错误的人，我联系了 heroku，他们告诉我用这个运行迁移:

$ heroku run bash --app appname

然后

$ rake db:migrate

出于某种原因，它奏效了......