Apache Accumulo® is a sorted, distributed key/value store that provides robust, scalable data storage and retrieval.


With Apache Accumulo, users can store and manage large data sets across a cluster. Accumulo uses Apache Hadoop's HDFS to store its data and Apache ZooKeeper for consensus. While many users interact directly with Accumulo, several open source projects use Accumulo as their underlying store.

To learn more about Accumulo, take the Accumulo tour, read the user manual and run the Accumulo example code. Feel free to contact us if you have any questions.

Major Features

Server-side programming

Accumulo has a programing meachinism (called Iterators) that can modify key/value pairs at various points in the data management process.

Cell-based access control

Every Accumulo key/value pair has its own security label which limits query results based off user authorizations.

Designed to scale

Accumulo runs on a cluster using one or more HDFS instances. Nodes can be added or removed as the amount of data stored in Accumulo changes.


Accumulo has a stable client API that follows semantic versioning. Each Accumulo release goes through extensive testing.