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Luke Chen commented on KAFKA-15537: ----------------------------------- [~fvaleri], thanks for raising this issue. Since you've dived into this issue, are you interested in submitting a PR for this issue? > Unsafe metadata.version downgrade is not supported > -------------------------------------------------- > > Key: KAFKA-15537 > URL: https://issues.apache.org/jira/browse/KAFKA-15537 > Project: Kafka > Issue Type: Bug > Reporter: Federico Valeri > Priority: Major > > In KIP-778 we introduced the "unsafe" downgrade functionality in case one of > the metadata versions between current and target have changes, as defined in > MetadataVersion. This is a lossy downgrade where each node rebuilds its > metadata snapshots, omitting the metadata changes. Currently, this is not > supported, as shown by the following command. > {code} > bin/kafka-features.sh --bootstrap-server :9092 downgrade --metadata 3.4 > --unsafe > Could not downgrade metadata.version to 8. Invalid metadata.version 8. > Unsafe metadata downgrade is not supported in this version. > 1 out of 1 operation(s) failed. > {code} > Also note that documentation says it's possible: "Note that the cluster > metadata version cannot be downgraded to a pre-production 3.0.x, 3.1.x, or > 3.2.x version once it has been upgraded. However, it is possible to downgrade > to production versions such as 3.3-IV0, 3.3-IV1, etc." > The error message could be improved: "Unsafe metadata downgrade is not > supported in this Kafka version." -- This message was sent by Atlassian Jira (v8.20.10#820010)