Apache Cassandra is a NoSQL database, decentralized storage system for managing large amounts of structured data. It is a free open source that differs from traditional relational database management systems . Cassandra is designed to scale to a very large size across many commodity servers, with no single point of failure .
Why Cassandra ?
Easy – It is very simple and easy to install and setup cassandra cluster .
Scalable – We can increase the number of nodes in cassandra cluster setup , while the cassandra is online , without down time .
No single point of failure – Data is replicated to multiple nodes to protect from loss during node failure, and new machines can be added incrementally while online to increase the capacity and data protection of your Cassandra cluster.
Performance – When comparing to MySQL , Cassandra can write 2,500 times faster than MySQL. It can write 50GB of data in 0.12ms , where MySQL can write 50GB of data in 300ms .
Cassandra Query Language (CQL) – Cassandra provides CQL , it is similar like SQL language that mirrors SQL’s DDL, DML, and SELECT syntax .
Cassandra is in use at Facebook, Twitter, Cisco, Rackspace , Digg , OpenX, and more companies that have large and active data sets.