I am preparing the documentation for another Cassandra cluster in a new datacenter and wonder how the bootstrap process of the seed nodes and non seed nodes should be done. For the most part I am following the steps from this blog.

Currently the cluster is on version 3.11.5 and the official documentation says nothing about the auto_bootstrap setting when setting up a new DC.

When I boot the nodes in the new DC one by one, I don't want to stream any data yet (keyspace has already been adjusted so that the new DC has replication factor 0). Shouldn't I rather set the auto_bootstrap setting to false or do I not understand something correctly?

In the Cassandra 2.2 documentation, it is explicitly pointed out that the setting should be set to false.

I hope I was able to explain my understanding problem.


2 Answers 2


When adding a new DC, you don't need to worry about setting that property one way or another. This is because when nodes are bootstrapped, they will only stream data from their local data center. As your data center is new, there isn't any data to stream. So in this case, it doesn't matter what that property is set to; no data will be streamed either way.

Therefore, follow the steps as described, and just be sure to run step #9 of

nodetool rebuild original_data_center_name_here

...on each node. That's the step that will bring data in from another DC.

  • 1
    Thanks! I missed somehow the little hint that it's about streaming data locally. Commented Sep 6, 2023 at 18:41

It isn't necessary to set auto_bootstrap: false in cassandra.yaml provided there are no replicas configured in the new DC.

When adding a new DC, it is necessary to re-configure keyspaces such that all keyspaces with replication set to SimpleStrategy should be switched to NetworkTopologyStrategy with replicas configured in the existing DC(s) using the ALTER KEYSPACE command. For example:

    'class' : 'NetworkTopologyStrategy', 'existingDC: 3'

This must be done BEFORE adding a new DC. Also note that you should NOT change the replication settings for system keyspaces which have been configured with LocalStrategy since those contain data specific to a node and should not be replicated to other nodes. Cheers!

  • Thank you for your comment, we have kept that in mind. There are only two system keyspaces that still need to be converted to NetworkTopologyStrategy from SimpleStrategy. Is an ALTER KEYSPACE sufficient or do we have to do a repair or something similar afterwards? Commented Sep 14, 2023 at 12:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.