ios-mqtt-client-framework

I'm trying to connect to our push server via MQTT-Client-Framework . There is no complication for connecting to server and with a few line of code i can connect to server and subscribe to topic. but I have a few question that I could not find any direct answer for them. 1) How can I keep my client running at background? 2) What happen after device restart? how can I automatically connect to server after device restart? 3)Suppose I got an error during connecting to server. Will this library trying to connect in a loop? how many times it try? or I need to manage this myself? 4) The same 3