I need to upgrade PHP 4.3.9 to PHP 5.2 (is there a better version...?) without lots of downtime as it is in a production environment. The new install also needs newer versions of GD and MySQL and needs to include mod_ssl. The server is running on CentOS 4.4.
I would prefer to use RPM or packages rather than compile (as I've never compiled anything before...linux newbie, also because of time involved). Is there an upgrade strategy that would ensure no or microscopic chance of failure? Upgrading to CentOS 5 is not out of the question depending on amount of time it takes and also chance of failure, although, CentOS 5 only includes PHP 5.1.6.
Again, of critical importance is that nothing breaks. The only PHP software I am using is CMS Made simple, which supposedly has worked fine with PHP 5 for a long time.