Hi Manish,the best way, if you have the opportunity to easily add new hardware/instances, is to create a new DC with racks and switch traffic to the new DC when it's ready (then remove the old one). My co-worker Alain just wrote a very handy blog post on that technique : http://thelastpickle.com/blog/2019/02/26/data-center-switch.htmlIf you can't, then I guess you can for each node (one at a time), decommission it, wipe it clean and re-bootstrap it after setting the appropriate rack.Also, take into account that your keyspaces must use the NetworkTopologyStrategy so that racks can be taken into account. Change the strategy prior to adding the new nodes if you're currently using SimpleStrategy.You cannot (and shouldn't) try to change the rack on an existing node (the GossipingPropertyFileSnitch won't allow it).Cheers,--On Wed, Mar 6, 2019 at 12:15 PM manish khandelwal <email@example.com> wrote:
We have a 6 node Cassandra cluster in which all the nodes are in same rack in a dc. We want to take advantage of "multi rack" cluster (example: parallel upgrade on all the nodes in same rack without downtime). I would like to know what is the recommended process to change an existing cluster with single racks configuration to multi rack configuration.
I want to introduce 3 racks with 2 nodes in each rack.
RegardsManish-----------------Alexander DejanovskiFrance@alexanderdejaConsultantApache Cassandra Consulting