Cassandra Keywords

 Cassandra Keywords

The main keywords which are used in Cassandra are Cluster, Datacenter, Node.
       

Cassandra Cluster
                     
Cluster: The outermost layer in the Cassandra Architecture is a Cluster. Cluster may contain one or more datacenters. It can also contain one datacenter from US and another datacenter from India. This both datacenters may also become a part of one Cassandra cluster. As Cassandra is a highly available system if we maintain to different datacenters in two different places we can still get our required data if one of the datacenters is down due to some reasons. 

Datacenter: Datacenter is a part of Cassandra cluster which contains nodes. It can have one single node or multiple nodes in one datacenter. The datacenter contains racks in which nodes are stored. By using replication strategies we can also place nodes of one datacenter into different racks. So that if one rack is unavailable for some reason still we can get the required data.           

Node: A node is where all the data we want to store using Cassandra will be stored. The data in the node is stored in the form of tables. We use Cassandra Query Language to create, update, delete, insert data into the Cassandra node. Node also consists of some basic information such as location of the node, number of keyspaces, number of tables etc.


                                                                                                                               




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