Ruby on Rails MySQL#08S01Bad握手 - 降级MySQL？

Question

我们最近在Ubuntu 10.04LTS服务器上从MySQL 5.1.41升级到5.1.61.我们有一个古老的RoR网络应用程序,现在给出了一个糟糕的握手错误:

Mysql::Error in MainController#index

#08S01Bad handshake

/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/vendor/mysql.rb:523:in `read'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/vendor/mysql.rb:153:in `real_connect'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/mysql_adapter.rb:389:in `connect'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/mysql_adapter.rb:152:in `initialize'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/mysql_adapter.rb:82:in `new'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/mysql_adapter.rb:82:in `mysql_connection'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:262:in `send'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:262:in `connection_without_query_cache='
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/query_cache.rb:54:in `connection='
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:230:in `retrieve_connection'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:78:in `connection'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/base.rb:763:in `columns'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/base.rb:2060:in `attributes_from_column_definition_without_lock'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/locking/optimistic.rb:45:in `attributes_from_column_definition'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/base.rb:1502:in `initialize_without_callbacks'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.3/lib/active_record/callbacks.rb:225:in `initialize'
#{RAILS_ROOT}/app/controllers/application.rb:48:in `new'
#{RAILS_ROOT}/app/controllers/application.rb:48:in `log_info'
/usr/local/bin/mongrel_rails:19:in `load'
/usr/local/bin/mongrel_rails:19

我用Google搜索并偶然发现http://bugs.ruby-lang.org/issues/5017,它告诉我这是一个Ruby MySQL扩展错误.我们没有使用MySQL gem.我们的网络应用程序非常古老而脆弱(Ruby v1.8.7,Rails v1.2.3,Mongrel 1.1.5).我们正在用Django重写代替它,所以我们只需要在接下来的几周内实现这一功能,直到我们用新网站替换它.

我们怎样才能克服这个错误？我认为降级到MySQL 5.1.41是处理这个问题的最佳方法,然后当我们在几周内开始使用新网站时,我们可以重新升级到5.1.61.但是,我有一个降级mysql的问题.这是我正在使用的命令:

sudo aptitude install mysql-server-5.1=5.1.41-3ubuntu12.10

但是,这告诉我Unable to find a version "5.1.41-3ubuntu12.10" for the package "mysql-server-5.1".我也试过了sudo aptitude install mysql-server-5.1=5.1.41,但那也行不通.如何让aptitude安装正确版本的MySQL？

Answer 1

而不是降级MySQL gem,可以修复数据库名称参数来解决"bad handshake"问题.

我找到了这个:https://github.com/rubygems/rubygems/issues/423它运作良好.

而不是做一个黑客在real_connect有可能添加"\0"在config/database.yml

production:
  database: "itsalive_production\0"
  adapter: mysql
  host: localhost
  encoding: UTF8
  ...

编辑
如果您使用\0数据库名称末尾的解决方案.你可能会发现发现这和自己解决问题,但无论如何,我提到它:
(至少在我的rails版本)
使用数据库字符串\0在年底做的时候给人的问题rake test.首先是在复制开发数据库定义之前删除测试数据库,然后使用包含测试数据库名称的SQL命令字符串.这将导致错误,因为\0在字符串的中间.

在我的情况下,我使用的本地开发数据库没有任何问题,因此我不需要使用\0该名称.
这是另一种解决方法(原始代码mysql_adapter.rb):

module ActiveRecord
  module ConnectionAdapters
    class MysqlAdapter

      alias_method :old_execute, :execute

      def execute(sql, name = nil) #:nodoc:
        # This is needed because database names can end with "\0" to fix
        # the issue with "handshake" when mysql server is newer than the gem
        # requires. E.g. called when loading the new test db when doing "rake test".
        sql = sql.delete("\0")

        old_execute(sql, name)
      end
    end
  end
end

Answer 2

我修好了它！降级 MySQL 就可以了。Django 网站上线后，我们将重新升级到 5.1.61。这是降级 MySQL 的命令：

sudo aptitude install mysql-server-5.1=5.1.41-3ubuntu12 mysql-client-5.1=5.1.41-3ubuntu12 mysql-server-core-5.1=5.1.41-3ubuntu12

我曾经apt-cache得到过确切的版本。