Removing a node

Reduce the size of a datacenter.

Use these instructions when you want to remove nodes to reduce the size of your cluster, not for replacing a dead node.

Attention: If you are not using virtual nodes (vnodes), you must rebalance the cluster.

Procedure

Check whether the node is up or down using nodetool status:
The nodetool command shows the status of the node (UN=up, DN=down):
If the node is up, run nodetool decommission.

This assigns the ranges that the node was responsible for to other nodes and replicates the data appropriately.

Use nodetool netstats to monitor the progress.
If the node is down:
- If the cluster uses vnodes, remove the node using the nodetool removenode command.
- If the cluster does not use vnodes, before running the nodetool removenode command, adjust your tokens to evenly distribute the data across the remaining nodes to avoid creating a hot spot.
If the node does not stop streaming data to other nodes because gossip has stale state data for the node, assassinate the node.