Cassandra cluster scaling – adding a new node

Cassandra scales very easily, and with zero downtime. This is one of the reasons why it is chosen over many other contenders. The steps are pretty straightforward and simple:

1. You need to set up Cassandra on the nodes to be added. Don't start the Cassandra process yet; first, follow these steps:

   1. Update the seed nodes in Cassandra.yaml under seed_provider.

   2. Make sure the tmp folders are clean.

   3. Add auto_bootstrap to Cassandra.yaml and set it to true.

   4. Update cluster_name in Cassandra.yaml.

   5. Update listen_address/broadcast_address in Cassandra.yaml.

2. Start all the new nodes one by one, pausing for at least 5 minutes between two consecutive starts.

3. Once the node is started, it will proclaim its share of data based on the token range it owns and start streaming that in. This could be verified using the nodetoolnetstat command, as shown in the following code:

   mydomain@my-cass1:/home/ubuntu$ /usr/local/cassandra/apache- cassandra-1.1.6/bin/nodetool -h 10.3.12.29...