The Cassandra was developed at Facebook for Inbox Search and it became an open-source in July 2008.
In March 2009, Apache accepted Cassandra and now Cassandra is one of the high level project of the Apache.
The Apache released a new version of Cassandra 3.5 on 2016-04-13.
It is open source, meaning its source code is freely available for anyone to study, modify and use.
The Cassandra is a highly scalable and high performance distributed NoSQL database.
It is a type of Column Stored NoSQL database.
I have already posted about, What is a Column Stored NoSQL Database?
The Apache Cassandra is a peer to peer architecture.
Some of the database system with high availability has Master – Slave format in which, if Master server is affected, the other Slave server also may affect.
In the peer to peer architecture, all nodes are equal and there are no any dependency on each other. Very easily, We can add or remove any node in the cluster.
Cassandra has distributed architecture and it can handle huge amount of data with high availability.
There are very rare chance of failure of the data because multiple nodes are running with same copies of data.
If one node is crashed, the data can available from the second nearest node. You can define Replication Factor value (number of nodes) by the time of creating a Keyspace.
Cassandra offers solutions for problem where your requirement is to have a very heavy write system and you want to have a quite responsive reporting system on top of that stored data.
A Cassandra data structures are very similar to any RDBMS data structures and it’s faster than RDBMS. The RDBMS people can easily learn and migrate into Cassandra.
Some of the Cassandra Features are:
It is Masterless Architecture,
Flexible and Dynamic Data Model,
Good with Data Compression,
Having a Cassandra Query Language (CQL),
It has Fault Detection and Recovery option, Having a good algorithm for Data Protection, Replicate data into multiple server.
Cassandra is a best option for applications like: Mobile Messaging Services, Internet Provider, Social Media Analytics, and other Data Mining related systems.
Some of the popular companies like: Facebook, Twitter, Netflix, Cisco, eBay, Reddit , Comcast, Adobe and others whose are using Cassandra to store large amount of data.