How to handle force close ionic app and inactive app

Hi team,
I build an app with ionic 3 and working good. But i got a scenario where user force closes app while still not wait till the entire data is not loaded. Then server end shows the socket exception and sometimes server hangs the database also showing connection pool problem. Does it because of mobile app usage? We have the same server hosting both website and mobile rest services. I need to know best practices to handle sessions from app end and when user minimize the app and after 30 minutes he again opens the app, data is not getting refreshed. Then i need to re-login to get data. How can i handle these situations? Thanks in advance.

Try to call the data from API on ngOnint() or ionDIdEnter()

Hi thanks for reply. I am getting data from nginit method block. Not included iondidenter.