anchor.diff:  %%====================================================================
   %% DELETE
   %%====================================================================
  -%delete_resource(Req, State) ->
  -%	DbName = get_db_name(Req),
  -%	Hosts = get_hosts(),
  -%	remove_db_on_hosts(DbName, Hosts),
  -%	{true, Req, State}.
  +delete_resource(Req, State) ->
  +	DbName = req_helper:get_db_name(Req),
  +	Key = req_helper:get_record_key(Req),
  +	Hosts = cluster:get_hosts(),
  +	TargetHost = select_host_for_key(Key, Hosts),
  +	remove_record(TargetHost, DbName, Key),
  +	{true, Req, State}.
   
   %%====================================================================
   %% Internal functions
   %%====================================================================
  +remove_record(TargetHost, DbName, Key) ->
  +	rpc:call(TargetHost, db_manager, do, [
  +		DbName, fun db_server:delete/2, [Key, db]]),
  +	ok.
  +
   record_to_json(Value) ->
   	jiffy:encode({[{value, Value}]}).
   
  
positive.code: 	case read_key_value(TargetHost, DbName, Key) of
  		{ok, Value} -> {true, Req, {value, Value}};
  		{error, instance} -> {false, Req, State}
  	end;
  resource_exists(Req=#{method := <<"PUT">>}, State) ->
  	%% It is not matter
  	{true, Req, State}.
  
  valid_content_headers(Req=#{method := <<"GET">>}, State) ->
  	{true, Req, State};
  valid_content_headers(Req=#{method := <<"PUT">>}, State) ->
  	IsContentTypeValid = cowboy_req:header(
  		<<"content-type">>, Req) == <<"application/json">>,
  	{IsContentTypeValid, Req, State}.
  %%====================================================================
  %% GET
  %%====================================================================
  
negative.code: 	DbName = req_helper:get_db_name(Req),
  	{not cluster:is_db_everywhere(DbName, Hosts), Req, State}.
  
  resource_exists(Req=#{method := <<"PUT">>}, State) ->
  	%% It is not matter
  	{true, Req, State};
  resource_exists(Req, State) ->
  	DbName = req_helper:get_db_name(Req),
  	Hosts = cluster:get_hosts(),
  	Key = req_helper:get_record_key(Req),
  