Apache Accumulo is a sorted, distributed key-value store based on Google's Bigtable, HDFS and Apache Zookeeper. 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.



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.