anchor.diff:  
   -define(CHECK_INTERVAL, 600000). % 10 minutes
   -define(RELISTEN_DELAY, 5000).
  +-define(CONFIG_SUBSCRIPTION, [{"query_server_config", "commit_freq"}]).
   
   -record(st, {
       mod,
  
positive.code: 
  
  init({Mod, IdxState}) ->
      ok = config:subscribe_for_changes([{"query_server_config", "commit_freq"}]),
      DbName = Mod:get(db_name, IdxState),
      erlang:send_after(?CHECK_INTERVAL, self(), maybe_close),
      Resp = couch_util:with_db(DbName, fun(Db) ->
  
negative.code:     erlang:send_after(?RELISTEN_DELAY, self(), restart_config_listener),
      {noreply, State};
  handle_info(restart_config_listener, State) ->
      ok = config:subscribe_for_changes(?CONFIG_SUBSCRIPTION),
      {noreply, State}.
  
  code_change(_OldVsn, State, _Extra) ->
  