I recently came across a tutorial on sitting Redis infront of WordPress allowing for insanely fast page generation. I gave it a try and it really works, in fact I’m now using it on this very site! The best part however is the fact that the script requires absolutely no modification to your existing WordPress site save for 1 line of htaccess. Truly amazing.
Below I’ll detail my slightly modified version of Jim’s script along with some metrics.
Firstly, What is Redis and what will it do for me?
The Redis website describes Redis as
… an open source, BSD licensed, advanced key-value store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets and sorted sets.
What does this mean? Essentially it’s Memcached but more useful. Redis stores key-value pairs in memory and spits them out when requested. Unlike Memcached it has built in persistence but what’s most important to us is that it’s fast – very fast.
We’ll be using Redis to speed up our site by loading cached pages from it directly without even booting up WordPress. This will save a large amount of page generation time and get out site infront of our users’ eyeballs faster.
Exactly how much faster are we talking?
In my very unscientific tests, loading www.flynsarmy.com a bunch of times resulted in the following:
| Before (Secs) | After (Secs) |
|---|---|
| 1.556 0.468 0.494 0.498 0.492 0.514 0.499 0.511 0.499 |
0.02001 0.00896 0.00883 0.00959 0.01472 0.00916 0.00915 0.00756 0.01989 |
As you can see from the table above this equates to a 20x to 50x speed increase and that was WITH W3 Total Cache installed! Results of course may vary but I think you get the picture.