This variable ensures that Kafka resets are not allowed by default, so as to provide safeguard against accidental misconfiguration causing a cluster split (see Switching Kafka for more information on Kafka resets).

With this variable unset by default, a change in the Kafka cluster ID or the HUMIO_KAFKA_TOPIC_PREFIX will cause nodes to crash until these two values match what is in the global snapshot. This prevents the cluster from acting on the change to Kafka until an administrator assents to having a Kafka reset performed.

To intentionally perform a Kafka reset, set ALLOW_KAFKA_RESET_UNTIL_TIMESTAMP_MS to an epoch timestamp in near future (for instance now + one hour), which will make sure that the setting is automatically disabled again once the reset is complete.