Websocket service always running

I am starting with a new project for mobile app, and I plan to use ReactNative as my framework and Socket.IO as my websocket. What I want to do with the socket is: my app needs to listen for new entrys in a database and, when it happens, a new notification is shown to the user.

So, I think the best way to do this, is use a service that is always running connected to my websocket. But I don't know if it's recommended because I don't know if it consumes too many resources (just as battery or hardware) to be running in background continuously. So my question is: is that the right way to do what I want? If not, what is the best one?