Digg is Switching to Cassandra

Digg, the San Francisco-based social media company, is choosing Cassandra over MySQL saying that they plan to open source all of their work on Cassandra. Digg's system needs to support allot of interaction with their 40 million uses a month, so they need something that can give fast reliable near-real-time information and have the ability to handle read and write requests at the same time. Cassandra can meet those needs of storing data and providing fast results for search queries.

Stu Hood, technical lead for the search team in the Email & Apps division of Rackspace, said,

"Cassandra has an approach that hybridizes the Bigtable and Dynamo models, where a lot of its competitors chose to take one path or the other. Over the Bigtable clones, Cassandra has huge high-availability advantages, and no single point of failure. When compared with the Dynamo adherents, Cassandra has the advantage of a more advanced data model, allowing for a single 'row' to contain billions of column/value pairs—enough to fill a machine. You also get efficient range queries for the top level key, even within your values."

And John Quinn, Digg's vice president of engineering, said

"Our primary motivation for moving away from MySQL is the increasing difficulty of building a high-performance, write-intensive application on a data set that is growing quickly, with no end in sight. This growth has forced us into horizontal and vertical partitioning strategies that have eliminated most of the value of a relational database, while still incurring all the overhead."