Apache Accumulo is a sorted, distributed key-value store based on Google's Bigtable and HDFS. First designed and developed by a team in NSA, Accumulo's mission is to support big data storing and processing, but at the same time enforce fine-grained data access control. In particular, the team in NSA extends Bigtable in a way that Accumulo can control the access of individual data elements. Accumulo is currently an open source project under Apache v2 license.


2006 Google publishes "Bigtable: A Distributed Storage System for Structured Data." In the same year, Yahoo! releases an open source version named Apache Hadoop.

January 2008 In order to solve the issue of storing and processing large amounts of data with different sensitivity level, a team of computer scientists and mathematicians in NSA are evaluating various big data technologies.

July 2008 The NSA team decides to begin a new Bigtable implementation.

September 2011 Accumulo becomes a public open source incubator project hosted by Apache Software Foundation.

March 2012 Version 1.3.5 is released. This is the first publicly available version.

April 2012 Version 1.4 is released.

May 2013 Version 1.5 is released. This version incorporates Thrift proxy and table import/export into Accumulo.

May 2014 Version 1.6 is released.

Storage Architecture


Accumulo is a disk-oriented database that relies on HDFS to store data.

System Architecture


Relying on HDFS to manage files, Accumulo applies a Shared-Nothing architecture.