Is it possible to mess something up by updating php on the production server?

Question

PHP

CentOS 6.6 32bit. On the server is 5.4.35 php. Added epel.repo and remi.repo. In remi.repo I set enabled=1 for [remi] and [remi-php55]. What are the implications of updating php with "yum update php-\*"? Maybe something needs to be saved? I ask because in one of the articles on this subject, the author wrote "if something stopped loading, for example apc, you need to reinstall it:", and it's just scary to spoil the working server :)

Answer 1

Yes maybe. By rearranging packages from different repositories, you can remove the dependencies necessary for the normal operation of the server.

Answer 2

No need to break the working server, without urgent need.

Answer 3

at least sites with PHP code that do not support PHP 5.5 will stop working, but there is no full backward compatibility there.