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Upon receiving a DeleteTopicsRequest, if the IBP is >= MIN_TOPIC_ID_VERSION move the /brokers/topics/[topic] znode payload to /admin/delete_topics_by_id/[topicId], and immediately reply to the DeleteTopicsRequest with a successful response. At this point, the topic is considered deleted, and a topic with the same name can be created.

While Although the topic is considered safely deleted at this point, it must still be garbage collected. The controller will then stage a send StopReplicaRequest(s) to all brokers assigned as replicas for the deleted topic. Upon successfully receiving a response from all replicas, the znode at /admin/delete_topics_by_id/[topicId] will be deleted.

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This leads to the question of what should be done if the controller never receives a successful response from a replica for a StopReplicaRequest. Under such a scenario we need to decide if it is still safe to remove the staged topic deletion from /admin/delete_topics_by_id/[topicId], after a reasonable number of retries and time. Given that LeaderAndIsrRequest v3 includes an is_every_partition flag, any stale partitions will be reconciled and deleted by the a broker on startup upon receiving the first initial LeaderAndIsrRequest. Therefore, it will be safe to remove the staged deletes after a reasonable number of retries, and we can let any brokers which did not receive the request clean these up on their next startup.

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