A Kannada word which literally means a young one of an animal or pet. ( Nayi mari= pup, Mari huli= tiger cub, Ili Mari= little mouse.)
You can call your young server "Ye Mari" but not an adult one. He will take offense if you did that.
It is a tad more respectful than just calling the tad by snapping fingers or yelling a "shoo, shoo" or "tch. tch." which some even-more-inconsiderate customers do.
Young boys or even girls in the family can also be addressed affectionately this way.