Ask questions, Andrews 4.0 background service is not running too long if you will automatically exit

Recently learning android's demo, a service running in the background, which Andrews the next day, there is no background 4.0, Android 2.1 has been.
4.0 is an internal system has this feature is not detected, how many hours did not reach the background service is running on the kick off?<-! Main posts under Banner (D4) -><-! Posts under the main text (D5) ->
Reply:
Automatically exit the system is likely to be under low memory situation will turn off not long recovery services used.
Plus a STICK mode will automatically start Service.