I don’t really look at server response times too much, because generally it’s a bit dull, really. If our server is really sick then the automatic alerts and text messages from Pingdom tell me to get fixing.
Anyway, tonight I just thought I’d have a look at some graphs. And hey, there’s a bit of a shock… my own site, this one here, is getting slower. Here’s the graph:
Now, what you’ll notice is that generally everything looked nice and brisk until early August 2009 when there was a marked deterioration in performance. Then it plodded along just fine until December 2009 when it got worse again.
Is It WordPress Bloat?
I wondered what had happened to cause this – I’m especially shocked that a page load is now so slow. I haven’t changed the theme in use for at least a year, and the plugins are generally ones I use elsewhere. So I did a bit of thinking, and then it dawned on me when I found this list of release dates at WordPress.org:
The dates correlate exactly with the worsening performance of this site.
Now, correlation absolutely does not relate to causality. At upgrade time I usually take a moment to review plugins, upgrade the theme, etc. It could be that an upgrade or change to one of the many plugins in use here that has caused the slowdown. I know it’s not traffic to my site – that’s been flat for ages, with only the occasional blip. The server is a dedicated machine running about fourty sites that we manage, but the load is generally quite consistent and impact on different websites is fairly well managed.
But I’m a speed freak. I like it when a website zings into view. I love fast cars. I love computers that don’t dither. I love telephones that respond instantly. So I hate that response times are now below 1s. That’s not on!
So I’m going to try to find the cause of this slowdown – I’ll be running some experiments on this site, profiling queries, checking the database over and so on. And I’ll document it all as a way of showing you how we at Interconnect IT do our performance tuning. Whether I document it here or there I haven’t decided yet – I think it would make a good case study for the site. We’ll see! Watch both sites…
note 1 – deactivated Twitme on 03/02/2010