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commit 150c14846b9d8f51e612e84443272fce9a6a468e Author: Arpit Goyal <[email protected]> AuthorDate: Tue Feb 10 01:13:54 2026 +0530 KAFKA-20096: Add documentation about the incompatibility of RocksDB file format (#21397) Document the limitation we have in RocksDB upgrade due to file format version change. Reviewers: Matthias J. Sax <[email protected]> --- docs/streams/upgrade-guide.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/docs/streams/upgrade-guide.md b/docs/streams/upgrade-guide.md index c4b0a673e92..2f948c6324a 100644 --- a/docs/streams/upgrade-guide.md +++ b/docs/streams/upgrade-guide.md @@ -53,7 +53,9 @@ Starting in version 4.0.0, Kafka Streams will only be compatible when running ag Downgrading from 3.5.x or newer version to 3.4.x or older version needs special attention: Since 3.5.0 release, Kafka Streams uses a new serialization format for repartition topics. This means that older versions of Kafka Streams would not be able to recognize the bytes written by newer versions, and hence it is harder to downgrade Kafka Streams with version 3.5.0 or newer to older versions in-flight. For more details, please refer to [KIP-904](https://cwiki.apache.org/confluence/x/P5VbD [...] -Downgrading from 3.0.x or newer version to 2.8.x or older version needs special attention: Since 3.0.0 release, Kafka Streams uses a newer RocksDB version whose on-disk format changed. This means that old versioned RocksDB would not be able to recognize the bytes written by that newer versioned RocksDB, and hence it is harder to downgrade Kafka Streams with version 3.0.0 or newer to older versions in-flight. Users need to wipe out the local RocksDB state stores written by the new version [...] +Downgrading from 3.0.x or newer version to 2.8.x or older version needs special attention: Since 3.0.0 release, Kafka Streams uses a newer RocksDB version whose on-disk format changed. This means that old versioned RocksDB would not be able to recognize the bytes written by that newer versioned RocksDB, and hence it is harder to downgrade Kafka Streams with version 3.0.0 or newer to older versions in-flight. Users need to first delete the local RocksDB state stores written by the new ver [...] + +Downgrading from 4.0.x or newer version to older than 4.0.0 needs special attention: Since 4.0.0 release, Kafka Streams upgraded RocksDB from version 7.9.2 to 9.7.3. This upgrade introduces a RocksDB file format version change from version 5 to version 6 (introduced in RocksDB 8.6). While the newer RocksDB version (9.7.3) can read state stores written in the old format (version 5), the older RocksDB versions cannot read state stores written in the new format (version 6). This means that [...] Kafka Streams does not support running multiple instances of the same application as different processes on the same physical state directory. Starting in 2.8.0 (as well as 2.7.1 and 2.6.2), this restriction will be enforced. If you wish to run more than one instance of Kafka Streams, you must configure them with different values for `state.dir`.
