I'd say that the hardest feature to learn, is the one that you don't care about. I can learn many things as a developer, but don't ask me for HA options.
When you have real interest, you'll learn faster and better.
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2