Scaling
Adding more nodes to Cassandra (scaling out) or shrinking the number of nodes (scaling in) is a pretty straightforward task. In a smaller and moderate-sized Cassandra cluster setup (say, less than 25 nodes), adding or shrinking nodes can be easily managed by doing the tasks manually. Alternatively, in larger clusters, the whole process can be automated by writing an appropriate shell script to perform the task.
Adding nodes to a cluster
Cassandra is one of the purest distributed systems, where the nodes are the same. Adding a new node is just a matter of launching a Cassandra service with almost the same parameters as any other machine in the ring. In a cloud environment, such as AWS, it is a pretty common practice to have a machine image of Cassandra that contains the blueprint of a Cassandra node. Each time you have to add a node to the cluster, you launch the Amazon Machine Image, tweak a couple of parameters that are specific to the node, and done. It is as simple as that.
To add...
