Removing a node
Reduce the size of a datacenter.
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, choose the appropriate option:
- 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 removenode fails, run nodetool assassinate.