Cloudera, a startup that helps companies process large amounts of data using an open source platform called Hadoop, has raised $6 million in a second round of funding.

The San Francisco company has an impressive founding team, including high-level folks from Facebook, Google, and Yahoo. Previous backers include Accel Partners, former VMware chief executive Diane Greene, former MySQL chief executive Marten Mickos, and Facebook chief financial officer Gideon Yu. Cloudera CEO Mike Olson says the eight-month-old startup has “tens of customers,” and is seeing growing interest in Hadoop, which is a relatively new technology. That interest comes from a wide range of markets, Olson says — web and mobile advertising, financial services, bioinformatics, government, and more.

Cloudera was the first company to offer commercial distribution and services for Hadoop, but recently Amazon also started selling infrastructure for Hadoop processing through a service called Amazon Elastic Map Reduce. Cloudera isn’t competing directly with Amazon, since the startup isn’t selling infrastructure, and in fact allows customers to use Amazon.

The company announced its $5 million first round in March. Why is it raising more money so soon? Olson says that first round actually closed back in October. Also, Cloudera didn’t need to raise the money now, but it just seemed like a good opportunity to accelerate the company’s growth, he says. The new round was led by Greylock Partners, with participation from Accel.