It is a column-oriented database that is used to store sparse data sets. It is run on the top of the Hadoop file distributed system. Apache HBase is a database that runs on a Hadoop cluster. Clients can access HBase data through either a native Java API or through a Thrift or REST gateway, making it accessible by any language. Some of the key properties of HBase include: • NoSQL: HBase is not a traditional relational database (RDBMS). HBase relaxes the ACID (Atomicity, Consistency, Isolation, Durability) properties of traditional RDBMS systems in order to achieve much greater scalability. Data stored in HBase also does not need to fit into a rigid schema like with an RDBMS, making it ideal for storing unstructured or semi-structured data. • Wide-Column: HBase stores data in a table-like format with the ability to store billions of rows with millions of columns. Columns can be grouped together in “column families” which allows physical distribution of row values onto different cluster nodes. • Distributed and Scalable: HBase group rows into “regions” which define how table data is split over multiple nodes in a cluster. If a region gets too large, it is automatically split to share the load across more servers. • Consistent: HBase is architected to have “strongly-consistent” reads and writes, as opposed to other NoSQL databases that are “eventually consistent”. This means that once a writer has been performed, all read requests for that data will return the same value.