In China, calling out 服务员！ to get a waiter's attention is standard and not considered rude. It's the normal way to flag down staff in a restaurant.
grammar
The suffix 员 (yuán) marks a person with a role: 服务员 (server), 售货员 (salesperson), 运动员 (athlete), 演员 (actor). It's one of the most productive person-role suffixes.
