Yep. These are all great points. This is the first set of many many tests to come but it was good to get a baseline. If you check the timestamps of the full tests, you'll see that all of them were run back to back to back within the course of about 2 hours total time, so there shouldn't be much variation. That said, locking down ALL of the potential variables is definitely something I'm striving for long term.
Hi Ryan, my name is Sean. I'm the GoDaddy product manager in charge of WordPress hosting. Thanks for including us and I'm glad we could surprise you with some fast speeds. In the past few months we've really made some huge strides in reducing page load times and are at some impressive speeds across the board right now. However, seeing your response times fall off a cliff surprised us too. There's been a big email thread going on this weekend to nail down exactly what happened so we can fix it :) I'd love to talk more and share some of the details around a new WordPress experience we're delivering in a few months. My email is in my HN profile.
Check what kind of traffic you are seeing on /xmlrpc.php.
What tends to happen is that spammers hit that file up and ask it to perform slow operations (the Wordpress team recently greatly expanded its capabilities). A PHP instance gets tied up for the duration. I've had instances lock up until killed by timeouts of 2 minutes.
When a bunch of traffic arrives at once, it only takes a handful of badly behaved instances of xmlrpc.php to render the server essentially inoperable.
I just went through this a few months ago. My bloggers don't use it and it can't be deactivated from within Wordpress any more, so I just 404 it in nginx.
Thanks for the tip. After reviewing Ryan's logs, it turns out a software security layer, Sentinel, was detecting the load test as a DoS attack since LoadImpact was sending all traffic from a single IP.
Hi Sean, it surprised me enough that I ran the test multiple times and came up with the same result over and over. I connected with Ben over the weekend and would love to talk with you guys some more!
