21–30 of 115 posts
TL;DR - Vanilla ubuntu, configure firewall, install nginx, install wordpress, turn on wordpress caching, install and configure varnish.
Isn't there any kind of static generator for Wordpress? I'd expect a static wordpress + nginx would be sufficient to handle quite a serious load.
These are all great tips to help you scale, but unless you've got a very small site WP site that is also doing 10M hits a day, there are many more complications. Once I have a little more spare time, I'll have to blog about some other solutions we've come up with.
TL;DR - Vanilla ubuntu, configure firewall, install nginx, install wordpress, turn on wordpress caching, install and configure varnish.
Pretty much, yeah - though if you don't know what settings to put on nginx and varnish, you'll end up wasting most of the performance. I'm sure my configurations aren't perfect, but they're a lot better than the defaults they ship with, and there doesn't seem to be a lot of "Here's some sensible settings" discussion on either project's website.
https://www.varnish-cache.org/trac/wiki/VCLExamples
At the bottom are some example templates that are a bit more tuned for production sites and are in use on some relatively large WordPress sites - last August, they claimed 8m pageviews/day on 3 frontend machines.
While I used to advocate W3TC, his support for Varnish purging has been ignored and I published a patch to fix it. Also, there are a number of tuning tweaks you can do - I don't know if you mounted your shmlog in ram or adjusted threading. The Debian packaged defaults are not very well planned - I don't know if Ubuntu blindly accepted Debian's defaults or repackaged with their own settings.
Nginx also includes its own proxy-cache which can eliminate the need for Varnish if you were still RAM starved. There are things you can do in Varnish VCL that you can't do in Nginx without writing your own module if that is an issue.
Since you're not running Apache with mod_rpaf, did you alter $_SERVER['REMOTE_ADDR'] processing? If not, most plugins and even commenting/trackback when used with Akismet would break.
Your worker-processes are probably not set well for nginx and there are a number of other tweaks that can help nginx quite a bit mostly with worker_connections and the rlimit_nofile (which if I recall, the default with a large site with w3tc's object caching would end up causing a bit of churn).
somaxconn might also have given a bit of a boost as you start having more traffic hit the backend. Not sure what version of PHP you get out of the repo or whether the backlog is patched, but, at some point, you'll need to adjust the backlog there for php-fpm - though, you would be well beyond the point of being able to run it on the ECS instance you tested with.
Good job benchmarking and actually including your config files.
The only way to make WP "fast" is to make it nearly completely static.
Get a half dozen people working admin area and your server will cry.
As someone who worked as lead dev for a blog network that does 10M+ visitors a month, here's the thing: if you've gotten your blog to 10M hits a day, you likely have a massive amount of content (we had about 1M posts over 5 or 6 years and about as many comments); that is, far too much to get into cache on a $15 server. Every page gets cached, every gallery page gets cached (if you've got photo galleries), every comme…
But I think that's the most likely cause of that kind of traffic on a small cheap VPS, as anyone running a big site without clustering is just being silly :)
Try it again with just the last step(vanilla apache/vanilla wordpress/varnish) what are your results like? Keep the original setup and have your test script perform some random searches. New figures? (Everything is fast/non-server intensive when you're serving static data)
I think the main difference between using Apache vs nginx as the backend server would be the amount of memory available for Varnish to use for caching. nginx has a much smaller memory footprint.
A blog is the most simple to scale application, just one step after the static content. The fact that wordpress has traditionally been not very scalable always used to puzzle me...
As someone who worked as lead dev for a blog network that does 10M+ visitors a month, here's the thing: if you've gotten your blog to 10M hits a day, you likely have a massive amount of content (we had about 1M posts over 5 or 6 years and about as many comments); that is, far too much to get into cache on a $15 server. Every page gets cached, every gallery page gets cached (if you've got photo galleries), every comme…
Of course, all this really lets you do is survive a swarm of people from (for example) here, digg, a tweet meme, stuff like that, which will direct everyone at one single page on your site. But I think that's the most likely cause of that kind of traffic on a small cheap VPS, as anyone running a big site without clustering is just being silly :)
Anyways, I'm all for articles like this that help optimize WP sites and get rid of the stigma that WP doesn't scale without cost. Thanks for writing it.