Replication-3,Consistency-Local_Quorum,Nodes-10,How many nodes
afford to go down so that application is not affected.
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if you have replication factor 3 per datacenter, and you read or write with LOCAL_QUORUM, you can at maximum afford to have one node down before your application is affected.
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To add to Bettina's answer, I think you missed the point.
Requests with consistency level
LOCAL_QUORUM with the recommended replication factor of 3 requires a quorum of 3 replicas -- with quorum being "50% + 1", that means 2 out of 3 replicas are required to satisfy the request.
As I understand it, you've passed the certification for both Administrator Associate and Developer Associate so I think you should be able to work out how many replicas you need for requests to succeed when you have 5 nodes down in a 20-node DC using the formula I provided. Cheers!
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