Cluster
The set of brokers that together store and serve all topics in a Kafka installation.
The cluster is Kafka's unit of deployment: a group of brokers coordinated with each other (via KRaft in current versions) that together provide fault tolerance and load distribution. Topics and their partitions are spread across the cluster's brokers; losing one broker doesn't bring down the whole cluster, as long as the affected partitions have replicas on other brokers.
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