The Total Hints metric group contains metrics regarding the hints for nodes and their status on success. Hint metrics can be used to determine if Cassandra nodes are not acknowledging one another. Should a node in a Cassandra Cluster fail to respond, its neighbours will generate hints and wait till it rejoins the cluster to begin replaying hints.
The metrics available are:
Total Hints – Number of hint messages written to this node from the time Cassandra service starts. Includes one entry for each host to be hinted per hint.
Hints Succeeded – Number of the hints successfully delivered.
Hints Failed – Number of the hints that failed deliver.
Hints TimedOut – Number of the hints that timed out.