code: def call(status)
        servers = @memcache.send(:ring).servers
        servers.each_with_index do |server, i|
          public_host_name = @alias ? "#{@alias} #{i + 1}" : "#{server.hostname}:#{server.port}"
  
          if server.alive?
            status.ok("#{public_host_name} is available")
          else
            status.fail("#{public_host_name} is not available")
          end
        end
      end
docs: Check if all the memcached servers in a cluster are responding.
   The memcache cluster to check is specified with the <tt>:cache</tt> options. The
   value can be either a Dalli::Client object (from the dalli gem) or an
   ActiveSupport::Cache::DalliStore (i.e. Rails.cache).
  
   If making the IP addresses of the memcache servers known to the world could
   pose a security risk because they are not on a private network behind a firewall,
   you can provide the <tt>:alias</tt> option to change the host names that are reported.
  
   === Example
  
     IsItWorking::Handler.new do |h|
       h.check :dalli, :cache => Rails.cache, :alias => "memcache server"
     end