That is a bit of a complex question.  From the SL side I can point you 
towards: 
http://ftp.scientificlinux.org/linux/scientific/7x/x86_64/release-notes/#_sl_provides_automatic_updates

On 08/10/2018 11:11 AM, Ken Teh wrote:
> I noticed that apply_updates in /etc/yum/yum-cron.conf is set to No on 
> a centos 7 system while it is set to Yes on SL7x.
>
> Is there any reason not to set to yes for centos?  I have cron job 
> that emails the user assigned to the desktop to reboot their machine 
> when updates have been installed. With apply_updates set to No, the 
> job fails to detect the install with 'yum history'. I can fix this but 
> I was wondering if there is some reason why I shouldn't configure the 
> daily yum cron the same way, ie, apply_updates=yes.
>
> Thanks.

-- 
Pat Riehecky

Fermi National Accelerator Laboratory
www.fnal.gov
www.scientificlinux.org