activerecord的一个猴子补丁，用于在失去与mysql服务器的连接后重新连接

Posted 2021-02-27

# Patch mysql adapter so that it reconnects after discovering an lost connection error
 
module ActiveRecord::ConnectionAdapters
  class MysqlAdapter
    alias :orig_execute :execute 
    def execute(sql,name=nil)
      orig_execute(sql,name)
      rescue ActiveRecord::StatementInvalid => exception
        if LOST_CONNECTION_ERROR_MESSAGES.any? { |msg| exception.message. =~ /#{msg}/ } 
          reconnect!
          retry
        else
          raise
        end
    end
  end
end