Nodetool cleanup

cleanup [<keyspace> <cfnames>...]- Triggers the immediate cleanup of keys no longer belonging to a node. By default, clean all keyspaces. This command cleans keys that no longer belong to the node. If no key is specified all the keyspaces will be removed. It’s important to use the nodetool cleanup command when adding or removing nodes of a cluster.

For example:

To clean up the data of a specific node use this command:

nodetool cleanup -h keyspace1

Nodetool Reference