When 100% is not 100%

Rackspace Managed Hosting is well known for their support and their 100% network uptime guarantee. One night last week, between approximately 23:31PDT and 23:51PDT there was an outage which affected Rackspace’s authoritative DNS servers and possibly other parts of their network. As a result, any site that uses Rackspace’s nameservers may or may not have worked during that time period. As my own personal domain uses Rackspace nameservers and was not working, I inquired about the outage and received the following reply from a Rackspace account manager:

“… Our SLA provides a 5% discount off your monthly fees for every 30 minutes of network downtime you incur. Your DNS connectivity problems lasted for a total of 20 minutes, therefore not constituted under the SLA as grounds for a discount.”

I guess that means that although they have a 100% network uptime guarantee, they don’t have to do anything about it as long as the outages occur in blocks of less than 30 minutes. Something about this doesn’t sound right to me…

Load balancer testing

Over the past week here at wordpress.com, we have been doing some experimentation with various software load balancers. In the latest test, we are using Pound with a weighted round-robin algorithm between all of the web servers in a given datacenter. The individual weight takes into account hardware differences and any other tasks that server may be doing. So, a dual processor server would receive more traffic than a single processor machine. The tests have been going really well so far.  Once the testing is complete and we have decided on a solution, I will post about the various things we tried, pros and cons of each, etc.  The graph below shows the load averages of the various web servers over a one week period. I’ll let you guess when the test began 🙂 Pretty dramatic difference, eh?

totals-web_load-week.png

Toobing!

So, I’m leaving on Thursday morning, heading back home to Texas for a week or so. I got tired of the 65 degree weather here in San Francisco and needed to experience the scorching 100 degree Texas heat once more this summer – yeah right. Regardless, should be a fun week ahead. Labor Day weekend will be filled with toobing on the Comal river. The week after I will be heading to Houston to meet up with some friends and work a little bit and then back to San Antonio to catch a flight early Saturday morning. Gotta love the Lone Star State…

What’s up top?

Some of you may be wondering [what|when|where|why] the header image came from, so here’s the answer. I actually took that picture at this year’s United States Formula 1 Grand Prix in Indianapolis, Indiana. The picture is of Robert Kubica’s BMW F1 car as it brakes at the end of the Hulman straight just before turn 8. The glowing red you see is actually the carbon brake disc, which gets so hot under braking, it actually glows. Pretty cool stuff!