All right folks, it’s that time of the year again – and I mentioned it in earlier posts that I usually call Oct. / Nov. something like the “conference madness”. And what would fit better than a re-cap on a talk I just gave yesterday at SMX Stockholm. I had the pleasure to close the conference sessions part with a 45 minutes solo-talk titled “Advanced Performance Optimization Strategies: 10 tips to make your site lightning-fast”.
Maybe you do remember a post I wrote over a year ago here on StateOfSearch where I basically talked about three different approaches and areas on how to speed-up a website. Interestingly enough, a lot of the stuff I mentioned there is still very much valid as of today – which is good, I think – but for SMX Stockholm, I decided to break it down in a lot of small and hopefully actionable advise. My goal was, to have tips that people really can start implementing right away – but I also had the challenge to squeeze something in for everyone, without actually knowing how much technical knowledge the audience has.
To make that happen, I decided to come up with ten different areas on how you can improve and then just deep-dive into each of those. If you prefer to just flip through the slides, here you go – but if you want to have some more background, be sure to keep’ on reading just below the deck where do comment on the different items:
And now, without further due, here is the latest on how to make sure site as fast as possible:
1) Reduce the amount of requests
Another big issue – especially when serving a lot of resources – is limitations in terms of parallelized requests per hostname. Even modern browsers do not allow more than six connections at a time. Using img1/img2/imgX.domain.com allows balancing requests to and between multiple sub-domains – which results in a massive improvement in performance due to more parallelized connections.
2) Decrease the size of each request
3) Implement a proper caching
Caching the remaining requests (after having them optimized as outlined just before) is key for your success. Doing so is pretty much straight forward and comes down to using the right HTTP cache headers: It’s important to specify one of Expires or Cache-Control max-age, and one of Last-Modified or ETag, for all cacheable resources. I strongly recommend checking out slides 25 / 26 on how to do so.
4) Clean-up that source-code
As for the next minutes I talked about various approaches to optimize the HTML source code. Especially since development is kind of an on-going process, your HTML does change quite a bit. And, of course, leaves room for performance optimization as well. So my advice on HTML was:
- Remove HTML comments
- Move inline CSS / JS to external files
- Don’t scale images using width / height
- Don’t use empty href-attributes
- Don’t use @import in CSS
Slides 27 to 34 do have all the details on that.
5) Consider asynchronous requests
And a lot more…
After talking quite some time about the sites and its components, I also decided to dive a little deeper into the server-side to get the maximum out of the hard- and software-setup as well: If you’ll jump to slide 37 you can find some handy tips on how to make your MySQL server faster. After that I also talked about the web-server itself (like Apache vs. nginx) as well as how to get the maximum out of PHP (including PHP accelerators + caching, using memcached sessions as well as switching to a PHP-fpm setup to really get PHP to the max).
Again, here’s the link to the full deck on SlideShare account: http://gdig.de/smxspeed
I hope you find some of the stuff usefully – as always I’m looking forward to feedback in the comments via mail, Twitter or whatever you prefer.