kowshik commented on a change in pull request #9001: URL: https://github.com/apache/kafka/pull/9001#discussion_r498574911
########## File path: clients/src/main/java/org/apache/kafka/common/feature/SupportedVersionRange.java ########## @@ -17,9 +17,16 @@ package org.apache.kafka.common.feature; import java.util.Map; +import java.util.Objects; +import org.apache.kafka.common.utils.Utils; /** - * An extended {@link BaseVersionRange} representing the min/max versions for supported features. + * An extended {@link BaseVersionRange} representing the min, max and first active versions for a + * supported feature: + * - minVersion: This is the minimum supported version for the feature. + * - maxVersion: This the maximum supported version for the feature. + * - firstActiveVersion: This is the first active version for the feature. Versions in the range Review comment: @junrao My response below. > I was thinking what if we relax the current check by just making sure that maxVersion of finalized is within the supported range. Basically in your example, if supported minVersion goes to 2, it's still allowed since it's less than maxVersion of finalized. However, if supported minVersion goes to 7, this fails the broker since it's more than maxVersion of finalized. If we relaxed the current check like you suggested, then, as of today the following will happen: The controller can not effectively finalize `minVersionLevel` for the feature, because, with a relaxed check we do not know whether all brokers in the cluster support a particular `minVersion` when the controller finalizes the `minVersionLevel` at a particular value. Supposing we want to keep the concept of `minVersionLevel` like the way it is now (i.e. it is the lowest version guaranteed to be supported by any broker in the cluster for a feature), then, `firstActiveVersion` provides the door to mutate it safely whenever the need arises. So when thinking about your suggestion, it is not clear to me if you are intending to alter the meaning of `minVersionLevel`? If so, please could you tell me what is the new meaning of `minVersionLevel` that you are proposing? > Your concern for the relaxed check seems to be around deploying a wrong version of the broker by mistake. Not exactly, my concern is a bit different. It is to be noted that `minVersionLevel` can not be changed through the `UPDATE_FEATURES` api. Assuming we want to maintain the meaning of `minVersionLevel` the way it is today, my concern is about how would one alter `minVersionLevel` for a feature when the need arises? This needs to be done without letting the versioning system misconstrue the intent with a feature version incompatibility. This is where usage of `firstActiveVersion` acts as a solution. It is a community driven change to advance `firstActiveVersion` in an AK release. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org