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Now that we include the leader epoch in the Metadata API, the producer will be able to add it to Produce requests to verify metadata consistency between the client and the leader. If the producer sees either the FENCED_LEADER_EPOCH or the in a produce response, it will refresh metadata and retry. Alternatively, in the case of UNKNOWN_LEADER_EPOCH in the response from , which means the producer has more recent metadata than the broker, it will refresh metadata the producer will simply backoff and retry. 

We think it may also be useful to add some randomness to the producer's periodic metadata refreshes to reduce the likelihood of the producer getting stuck on stale metadata, but this is an internal detail and not explicitly in the scope of the KIP.

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