March 10, 2011 
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It was my experience that people approached an online purchase of six dollars with the same deliberation and thoughtfulness they might bring to bear when buying a new car. Prospective users would hand-wring for weeks on Twitter and send us closely-worded, punctilious lists of questions before creating an account.
(Full Story: Anatomy of a Crushing – Pinboard.in Blog)
December 22, 2010 0 Comments
Varnish stores data in virtual memory and leaves the task of deciding what is stored in memory and what gets paged out to disk to the operating system. This helps avoid the situation where the operating system starts caching data while they are moved to disk by the application.Furthermore, Varnish is heavily threaded, with each client connection being handled by a separate worker thread.
(Link: Varnish Community – Varnish speeds up your web site)
December 22, 2010 0 Comments
We knew we wanted to build out the election results as part of our usual stack, but we also knew the setup — given its scale and profile — needed to be resilient against the following:
Varnish failure — varnishd, so far, has never crashed on us. But hardware failure, misconfiguration or a strange bug could also put varnish offline.Application errors — no matter how rigorous your testing, live data feeds for live events always invite unexpected quirks. We wanted our readers to be well-insulated from any errors that might crop up.Extreme traffic — historically, election nights bring some of the most intense traffic of the year. Not only did we want to avoid overloads, but we also wanted to make sure response times were consistent and fast.
(Link: Using Flat Files So Elections Don’t Break Your Server – NYTimes.com)
September 17, 2010 0 Comments
Data Center Knowledge reports that Facebook is now spending $50 million a year to lease data center space, compared to $20 million in May 2009. The leap in costs is not surprising given that the social networking site has grown from 200 million users worldwide in mid 2009 to 500 million now.
(Link: Facebook’s $50m data center bill)
September 11, 2010 0 Comments
Rack::Bug adds a diagnostics toolbar to Rack apps. When enabled, it injects a floating div allowing exploration of logging, database queries, template rendering times, etc.
(Link: Rack::Bug adds a diagnostics toolbar to Rack apps.)
August 18, 2010 0 Comments
How do you scale an AWS (Amazon Web Services) infrastructure? This article will give you a detailed reply in two parts: the tools you can use to make the most of Amazon’s dynamic approach, and the architectural model you should adopt for a scalable infrastructure.
(Link: Scaling an AWS infrastructure – Tools and Patterns)
June 25, 2010 0 Comments
Facebook serves 570 billion page views per month (according to Google Ad Planner).
There are more photos on Facebook than all other photo sites combined (including sites like Flickr).
More than 3 billion photos are uploaded every month.
Facebook’s systems serve 1.2 million photos per second. This doesn’t include the images served by Facebook’s CDN.
More than 25 billion pieces of content (status updates, comments, etc) are shared every month.
Facebook has more than 30,000 servers
(Link: Exploring the software behind Facebook, the world’s largest site | Royal Pingdom)
February 8, 2010 0 Comments
The ratio of data reads to writes 3:1, which is an incredibly high write rate. A majority of the requests hitting the backend for FarmVille in some way modifies the state of the user playing the game. To make this scalable, we have worked to make our application interact primarily with cache components. Additionally, the release of new content and features tends to cause usage spikes since we are effectively extending the game. The load spikes can be as large as 50% the day of a new feature’s release. We have to be able to accommodate this spikey traffic.
(Link: How FarmVille Scales to Harvest 75 Million Players a Month)
