I have an existing production application which is deployed on 5 racks; our application is sized for two rack failure. Now we are adding cassandra as new technology into our application.
I am thinking of going with 5 node cassandra cluster where each rack will have one node, all nodes will be active and will be part of cluster. The replication factor is 3 in our case and we sized the nodes appropriately so we can survive two node/rack failure.
The question is what is the better topology for this requirement?
1. 5 nodes on 5 racks
2. 6 nodes on 3 racks
What would be some of the design consideration I should be made.