A snitch determines the datacenters and racks to which nodes belong. Snitches inform the database about the network topology, ensuring requests are routed efficiently. Snitches enable DataStax Enterprise (DSE) to distribute replicas by grouping machines into datacenters and racks. Specifically, the replication strategy places the replicas using the information that the new snitch provides.

All nodes in a cluster must use the same snitch.

DSE strives to avoid placing more than one replica on the same rack (which is not necessarily a physical location).