Stack Overflow: How we upgrade a live data center

I love reading about StackOverflow, particularly their infrastructure.<p>The site has been a useful resource for so many years, and it works so well. It was a joy to discover that it all ran on like two racks worth of servers, and still does. Having seen corporate intranet portals, with maybe a thousand daily active users, running on excessive* hardware (needlessly, of course), it&#x27;s like a breath of fresh air.<p>*EDIT: Removed hyperbole. Not more hardware, but too much nonetheless.

Perhaps off topic, but this post just reminds me so much of why I love AWS EC2, etc. Not ever having to think about hardware again is wonderful.

Woah, the datacenter you guys moved to is across the street from my apartment. Just a heads up, I considered it for a project myself but ruled it out because... well this is the back corner of that building: <a href="http://40.media.tumblr.com/tumblr_lqnh988WRS1qzpdb2o4_1280.jpg" rel="nofollow">http:&#x2F;&#x2F;40.media.tumblr.com&#x2F;tumblr_lqnh988WRS1qzpdb2o4_1280.j...</a>

I&#x27;m really wondering how SO uses Redis.<p>For example, how failure scenarios handled and what is the role of slaves.

That&#x27;s a really nice cabling job. I&#x27;ve inherited 2 DC&#x27;s with just-awful-enough cabling that I&#x27;d be exceptionally happy to set up new racks again and migrate, just to <i>sort the bloody cables out</i><p>Sigh, don&#x27;t think it&#x27;s gonna happen.<p>As a customer of Dell, it was interesting to see someone elses insight on managing a dell farm.<p>So neat! I am mildly envious! ;)

&gt; We learned that accidentally sticking a server with nothing but naked IIS into rotation is really bad. Sorry about that one.<p>Wait, does that mean what I think it means? Did someone get an IIS splash page when visiting SO?<p>I was going to say they should live-blog during their next upgrade but it they did it on twitter which is awesome.

I think what impressed me most was the power density that data center is supporting. That looks like nearly 10kW of power in a single rack! Many providers top out at 4kW and HE2 in Fremont was just 1.8kW per rack when I was there.

<i>Most companies depreciate hardware across 3 years</i><p>Can somebody explain why exactly? Was there ever some large scale research with the outcome this was somehow the cheapest? Or is it a mere byproduct of the consumption-based society? I&#x27;m asking because I&#x27;ved used lots of different types of hardware (both computing and non-computing) and &gt;90% lasted <i>well</i> over 3 years. It seems a waste of time&#x2F;money to get rid of ot after 3 years? Which matches with SE&#x27;s findings: they choose 4 years. Still not that much, but already &#x27;better&#x27;

Reading this brought back fond memories. Or nightmares. Sometimes it&#x27;s difficult to distinguish between the two.

If anything you can see the enthusiasm and passion they have for their job. It&#x27;s inspiring!

Thanks for sharing! Happy to see some of my past work in action.