Bringing together the Apache Cassandra experts from the community and DataStax.

Want to learn? Have a question? Want to share your expertise? You are in the right place!

Not sure where to begin? Getting Started

 

question

vkayanala_42513 avatar image
vkayanala_42513 asked ·

Can I rebuild Cassandra nodes that are added to existing datacenter?

Unintentionally we have lost (terminated in AWS console for a manual error) 5/12 Cassandra nodes from a AWS datacenter. So we are trying to get new nodes to replace them after "nodetool removenode" on dead nodes.

Can I add new servers to existing datacenter with "auto_bootstrap: false" and run nodetool rebuild on new nodes?


And Can I run nodetool rebuild on multiple nodes at a time? if yes, what could be the downside of it?


Thanks in Advance!

cassandra
1 comment
10 |1000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

I just got to know that, yes, we can do. Normally this is how to rebuild a whole DC but we can also use it to rebuild just a subset of nodes.

0 Likes 0 · ·

1 Answer

Erick Ramirez avatar image
Erick Ramirez answered ·

@vkayanala_42513 you can but when you disable auto bootstrap, the node will automatically join the cluster without any data on it and it will accept reads from the application (without data to return) so will cause you issues. It is a bad idea to do this unless you are adding nodes in a DC that is not serving traffic to the application. If you allow a node to bootstrap normally, it won't accept any read requests until the bootstrap has completed. Cheers!

1 comment Share
10 |1000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

@Erick Ramirez This is what I did.

- Add new nodes to cluster with auto_bootstrap false in cassandra.yaml.
- Perform a nodetool rebuild pointing to the other DC in the cluster.
- repairing old nodes in cluster.

Cheers!

0 Likes 0 · ·