CASSANDRA

CASSANDRA      

Basics of Cassandra

Cassandra is a NoSql, distributed, highly available, fault-tolerant, tunable consistent, decentralized, linearly scalable database. Cassandra is a write heavy database. If your application is write heavy application then Cassandra is suggestable. 

Cassandra is designed by using Amazon's Dynamo(for it's distribution design) and Google's Bigtable(for it's data modelling) with a query language which is similar to the SQL. 

The basic understanding of Cassandra's characteristics:

  • Distributed: The data which is stored in the Cassandra is distributed among all the nodes of the Cassandra cluster. Hence it is a distributed system.     
  • Highly Available: In Cassandra there is a replication factor which replicates the data into the other nodes makes it highly available.  
  • Fault-Tolerant: In Cassandra the process of storing and retrieving of data is unstoppable also if there is a problem in one of the nodes or two of the nodes based on the consistency level.      
  • Tunable Consistency: The consistency of the data is tunable by the user in Cassandra. But higher the consistency level, lower the availability.
  • Decentralized: Cassandra is a "masterless" system. In Cassandra every node is considered as a master. So, it eliminates the drawbacks caused by a master-slave system.
  • Linearly Scalable: In Cassandra we can add or remove a node very easily without disturbing any other nodes. Hence it is linearly scalable.


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