MithaJoseph created KAFKA-19704: ----------------------------------- Summary: Kafka Broker Fails to Start After Upgrade to 4.1.0 Due to Invalid segment.bytes Configuration Key: KAFKA-19704 URL: https://issues.apache.org/jira/browse/KAFKA-19704 Project: Kafka Issue Type: Bug Reporter: MithaJoseph
After upgrading our Kafka brokers to version {*}4.1.0{*}, the broker fails to start due to a misconfigured topic-level {{segment.bytes}} setting. The new version enforces a *minimum value of 1MB (1048576 bytes)* for this configuration, and any value below this threshold causes the broker to terminate during startup. *Error Details:* ** {code:java} [2025-09-12 14:39:51,285] ERROR Encountered fatal fault: Error starting LogManager (org.apache.kafka.server.fault.ProcessTerminatingFaultHandler) org.apache.kafka.common.config.ConfigException: Invalid value 75000 for configuration segment.bytes: Value must be at least 1048576 at org.apache.kafka.common.config.ConfigDef$Range.ensureValid(ConfigDef.java:989) ~[kafka-clients-4.1.0.jar:?] {code} In our setup, some topics were previously configured with a lower segment.bytes value (e.g., 75000), which was allowed in earlier Kafka versions but is now invalid. As a result Kafka broker cannot start, leading to downtime and unavailability.No snapshot file exists yet, so the {{kafka-metadata-shell}} tool cannot be used to patch the config offline. Please help us with the following: * Are there any supported methods from Kafka 4.1.0 to override or bypass this validation at startup to recover without losing data? * If not, is there a documented approach to fix such configuration issues when snapshots are not yet available? -- This message was sent by Atlassian Jira (v8.20.10#820010)