Dynamic snitching

Monitors the performance of reads from the various replicas and chooses the best replica based on this history.

cassandra.yaml

The location of the cassandra.yaml file depends on the type of installation:
Package installations /etc/dse/cassandra/cassandra.yaml
Tarball installations installation_location/resources/cassandra/conf/cassandra.yaml

By default, all snitches use a dynamic snitch layer that monitors read latency and, when possible, routes requests away from poorly-performing nodes. The dynamic snitch is enabled by default and is recommended for use in most deployments. For information on how this works, see the Dynamic snitching in Cassandra: past, present, and future blog post. Configure dynamic snitch thresholds for each node in the cassandra.yaml configuration file. Also, see the properties listed under About failure detection and recovery.