本人 Ruby 新手一枚～ 刚刚开始自学 最近想给网站写一个 health check，具体代码如下

class HealthCheckController < ApplicationController

  def dbping
    begin
      result = ActiveRecord::Base.connection.select_value("select 'alive' from dual")
      render :text => "#{result}\n"
    rescue => ex
      logger.error ex.backtrace.join("\n")
      raise ActiveRecord::ConnectionNotEstablished
    end
  end

  #run a simple query to check the database
  def deep_health
    begin
      result = ActiveRecord::Base.connection.select_value("XXXXXXXXXXXXXXX")
      render :text => "#{result}\n"
    rescue => exception
      #log the error
      logger.error exception.backtrace.join("\n")
    end
  end
end

实际检测网页中，dbping 是好用的，但是／deep_health 则出现了 template is missing 的情况。真心求助各位大大