I\'m targeting sdk version 27 with a minimum version of 19 and trying to get a service that runs continuously in the background. I tried different service start options but
In oreo release Android defined limits to background services.
To improve the user experience, Android 8.0 (API level 26) imposes limitations on what apps can do while running in the background.
Still if app need to run its service always, then we can create foreground service.
Background Service Limitations: While an app is idle, there are limits to its use of background services. This does not apply to foreground services, which are more noticeable to the user.
So create a foreground service. In which you will put a notification for user while your service is running. See this answer (There are many others)
Now what if you don't want a notification for your service. A solution is for that.
You can create some periodic task that will start your service, service will do its work and stops itself. By this your app will not be considered battery draining.
You can create periodic task with Alarm Manager, Job Scheduler, Evernote-Jobs or Work Manager.
I created forever running service with Work-Manager, that is working perfectly.