anchor.diff:         %% Prefix of the log files within the log path that should be rotated.
          {log_prefix, "memcached.log"},
          %% Number of recent log files to retain.
  -       {log_generations, 10},
  +       {log_generations, 20},
          %% how big log file needs to grow before memcached starts using
          %% next file
  -       {log_cyclesize, 1024*1024*100},
  +       {log_cyclesize, 1024*1024*10},
          %% flush interval of memcached's logger in seconds
          {log_sleeptime, 19},
          %% Milliseconds between log rotation runs.
  
positive.code:     DataDir = get_data_dir(),
      do_upgrade_files_from_2_0_to_2_2_0(DataDir),
      do_upgrade_config_from_2_0_to_2_2_0(Config, DefaultConfig, DataDir).
  
  search_sub_key(Config, Key, Subkey) ->
      case ns_config:search(Config, Key) of
  
negative.code:                   {set, {node, node(), ns_log}, default_ns_log}
                   ], Result2).
  
  upgrade_2_2_0_to_3_0_test() ->
      Cfg = [[{{node, node(), memcached},
             [{log_generations, 10},
              {log_cyclesize, 1024*1024*100}]}]],
      UpgradedCfg = upgrade_config_from_2_2_0_to_3_0(Cfg),
      ?assertEqual([
                    {set, {node, node(), memcached},
                     [{log_generations, 20},
                      {log_cyclesize, 1024*1024*10}]}], UpgradedCfg).
  
  no_upgrade_on_current_version_test() ->
      ?assertEqual([], upgrade_config([[{{node, node(), config_version}, get_current_version()}]])).
  
  