Upgrade procedures for CodeIgniter and WordPress applications on Debian Linux, PHP, Apache, and MySQL

I'm a programmer that recently moved to a company where I need to start thinking about keeping software libraries and a Debian Linux LAMP stack on their current versions.

Before I jump in I'm curious on how others usually do this with the least amount of frustration. :)

We run applications that use CodeIgniter and others that use WordPress. Is it best to upgrade these before upgrading the Debian LAMP stack or the other way around?

In addition, what do others consider "best practices" on how often to upgrade? My first thoug开发者_运维问答ht would to do this annually.

Thanks! Jason

---

In my company we have a production and a test environment, we usually upgrade the test server first, after that, we run test cases, and if the test cases went OK, within a couple of days we patch the production server, if the test cases fails, we try to fix them.

I don't have experience in codeigniter and wordpress, we use QCubed and other frameworks, first if a new release is out, we check requirements, then upgrade these first, and then the LAMP stack update comes after, all this in the test server. It really depends on the requirements of the software which updates first.