CODEWITHSUNDEEP
datastaxcassandra-2.1
Vinod Jayachandran
Vinod Jayachandran

Reputation: 3898

Converting 2 node cassandra Cluster to 1 node cluster

I have 2 node cassandra cluster. I intend to split them to two single node clusters.

  1. Shut Down Both Cassandra Instances
  2. Edit cassandra.yaml in both nodes, Changed seeds to point to self, and set endpoint_snitch: SimpleSnitch
  3. Start Cassandra on both nodes

Nodetool Status command on both the nodes shows 2 nodes, while I expect only one node.

What am I doing wrong ?

Upvotes: 0

Views: 254

Answers (1)

markc
markc

Reputation: 2158

The problem here is that each node still thinks its part of a 2 node cluster. It will remain like this until you tell it otherwise. Assuming you need to keep the data on each node then you need to run nodetool removenode <id> on each node for the other node thats showing up as DN in the output of nodetool status. If you didn't need the data on both nodes you can also use nodetool decommission

For some background information on removing nodes please see this link.

Note that if you intend to re-join these two nodes together then I would strongly advise you wipe and bootstrap one of the nodes into the the existing cluster since you can end up with a schema disagreement trying to join two clusters.

Upvotes: 1

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