KAFKA-9938; Debug consumer should be able to fetch from followers #8585
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| // Restrict fetching to leader if request is from follower or from a client with older version (no ClientMetadata) | ||
| val fetchOnlyFromLeader = isFromFollower || (isFromConsumer && clientMetadata.isEmpty) | ||
| // Restrict fetching to leader if request is from follower or from an ordinary consumer | ||
| // with an older version (which is implied by no ClientMetadata) |
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Seems like this comment is a bit redundant. The main useful info is that no ClientMetadata means older version, could we have a method name that made that clear and then the comment would not be needed?
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The second question is: do we want to allow this debugging consumer id behavior at all? Is it useful in the new world?
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Yeah, I was debating the latter. It's probably unlikely that this is used outside of the ReplicaVerificationTest. As far as I know, no one has filed an issue about it, so maybe we could drop this support. I decided to err on the side of compatibility, but I could probably be convinced to change my mind.
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Can we remove DebuggingConsumerId altogether or is there any functionality that it provides in today's world? If it doesn't provide any useful functionality now, I would just remove it and it's one less concept to support and think about. As you said, I don't think anyone actually uses this outside of the ReplicaVerificationTool.
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If there are any use cases which rely on it, users can upgrade their clients to regain the ability. Since no one has evidently noticed that this functionality was lost, I think it's probably fine to remove it.
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retest this please |
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Only known flaky test failures: |
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I am going to close this. Since the new |
There was a minor regression in the fetch protocol introduced in 2.4 as part of the KIP-392 work. We should allow the "debug consumer" to read from follower regardless of the protocol version.
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