Page History

...

1. Format time:  An administrator prepares a new broker with log.segment.bytes=1024 in server.properties and runs kafka-storage format --release-version 4.4. Before writing any data to disk, the tool validates the static configs against the constraints of IBP_4_4_IV1 and finds that log.segment.bytes=1024 violates the minimum of 3 MB. The command fails with a descriptive error, prompting the administrator to fix server.properties before retrying.
2. AlterConfigs at runtime: Once the cluster is running at IBP_4_4_IV1, an administrator attempts to set log.segment.bytes=1024 on a topic via AlterConfigs. The controller validates the proposed value against the current MV's constraints and immediately rejects the request with an INVALID_CONFIG error before any change is persisted.
3. Metadata version upgrade: A cluster is running at IBP_4_3_IV0. Topic payments has a long-standing dynamic override of log.segment.bytes=1024. , where brokers do not yet report static configs to the controller, leaving it with no visibility into each broker's server.properties. Broker node-3 also has has log.segment.bytes=2048 in its server.properties; since log.segment.bytes has an MV validator, this value was reported to the controller during registration and persisted in the metadata log. When the administrator , but the controller is unaware of this. As the administrator performs a rolling binary upgrade, each restarted broker begins sending StaticConfigs in  BrokerRegistrationRequest version 6; since log.segment.bytes now has an MV validator registered, it is included in the payload and stored by the controller in memory even while the cluster is still at  IBP_4_3_IV0. When the administrator then requests an upgrade to IBP_4_4_IV1, the controller audits all effective configs — both dynamic overrides and the static configs reported by each broker — and finds two violations — the version that simultaneously introduces static config reporting and the new log.segment.bytes minimum constraint — the  controller performs a pre-flight audit using the reported static configs and finds that node-3's log.segment.bytes=2048 violates the new minimum of 3 MB. The upgrade is rejected with a descriptive error listing both  the topic and the broker. The administrator fixes both values and retries, at which point identifying the broker and the offending value. Since the cluster is still at IBP_4_3_IV0 and fully operational, the administrator can issue an AlterConfigs request to set a cluster-wide dynamic override for log.segment.bytes to a compliant value, which takes precedence over the static value in server.properties without requiring any file editing or broker restart. The administrator then retries the upgrade, the pre-flight audit finds all effective configs compliant, and the upgrade proceeds successfully.

...