Hi Neo,
Unfortunately the upgrade from 8.2 to 8.3 or higher is not straight forward as the Debian release requirement is different
Migrate OPMS 8.2 to Later Versions - CA App Synthetic Monitor - CA Technologies Documentation
however with 8.7 you are no longer restricted to use Debian as the OS as we now support the following
Debian GNU/Linux 8
Red Hat Enterprise Linux 7
Oracle Linux 7
CentOS 7
So as you effectively need to reinstall an OS for this anyway you may wish to take the opertunity to use a different one if more appropriate to your site standards
thanks
Mike