In the previous post we’ve seen how data distribution in Cassandra works. But what if one of the nodes fails? If you want to ensure fault tolerance, you need to enable data replication. When you create a keyspace in Cassandra, you must decide the replica placement strategy: the number of replicas and how those replicas are distributed across nodes in the cluster. The replication strategy relies on the cluster-configured snitch to help it determine the physical location of
This strategy places the original row on a node determined by a practitioner and then a copy of the row is placed on the next node walking clock-wise in the cluster.
This is the default snitch used and uses a simple strategy of placing the copy of the row on the next available node walking clockwise through the nodes.
Is used to determine the location of the nodes by referring to the cassandra-topology.properties file.