Kafka 3.8 → 3.9 Upgrade Guide

Kafka 3.9 brings 24 new configs, removes 1, and changes 10 defaults compared to 3.8.

+24 configs −1 configs 10 defaults changed 11 KIPs

Removed Configurations

Config	Category
group.consumer.migration.policy	broker

New Configurations

Config	Category	Default
alter.config.policy.kraft.compatibility.enable	broker	false
controller.quorum.bootstrap.servers	broker
group.share.delivery.count.limit	broker	5
group.share.heartbeat.interval.ms	broker	5000 (5 seconds)
group.share.max.groups	broker	10
group.share.max.heartbeat.interval.ms	broker	15000 (15 seconds)
group.share.max.record.lock.duration.ms	broker	60000 (1 minute)
group.share.max.session.timeout.ms	broker	60000 (1 minute)
group.share.max.size	broker	200
group.share.min.heartbeat.interval.ms	broker	5000 (5 seconds)
group.share.min.record.lock.duration.ms	broker	15000 (15 seconds)
group.share.min.session.timeout.ms	broker	45000 (45 seconds)
group.share.partition.max.record.locks	broker	200
group.share.record.lock.duration.ms	broker	30000 (30 seconds)
group.share.session.timeout.ms	broker	45000 (45 seconds)
remote.log.manager.copier.thread.pool.size	broker	-1
remote.log.manager.expiration.thread.pool.size	broker	-1
sasl.oauthbearer.header.urlencode	consumer	false
sasl.oauthbearer.header.urlencode	producer	false
remote.log.copy.disable	topic	false
remote.log.delete.on.disable	topic	false
sasl.oauthbearer.header.urlencode	connect_default	false
log.summary.interval.ms	stream	120000 (2 minutes)
processing.exception.handler	stream	org.apache.kafka.streams.errors.LogAndFailProcessingExceptionHandler

Changed Defaults

Config	Old Default	New Default
inter.broker.protocol.version	3.8-IV0	3.9-IV0
ssl.enabled.protocols	TLSv1.2,TLSv1.3	TLSv1.2
ssl.protocol	TLSv1.3	TLSv1.2
ssl.enabled.protocols	TLSv1.2,TLSv1.3	TLSv1.2
ssl.protocol	TLSv1.3	TLSv1.2
ssl.enabled.protocols	TLSv1.2,TLSv1.3	TLSv1.2
ssl.protocol	TLSv1.3	TLSv1.2
ssl.enabled.protocols	TLSv1.2,TLSv1.3	TLSv1.2
ssl.protocol	TLSv1.3	TLSv1.2
client.id	<application.id>-<random-UUID>	<application.id&gt-<random-UUID>

Protocol Changes

Fetch v17 · Fetch v17 · ListOffsets v9 · ListOffsets v9 · FindCoordinator v6 · FindCoordinator v6 · ApiVersions v4 · ApiVersions v4 · Vote v1 · Vote v1 · BeginQuorumEpoch v1 · BeginQuorumEpoch v1 · EndQuorumEpoch v1 · EndQuorumEpoch v1 · DescribeQuorum v2 · DescribeQuorum v2 · FetchSnapshot v1 · FetchSnapshot v1 · BrokerRegistration v4 · BrokerRegistration v4

KIPs Released

KIP-853 KRaft Controller Membership Changes
KIP-932 Queues for Kafka
KIP-950 Tiered Storage Disablement
KIP-956 Tiered Storage Quotas
KIP-1005 Expose EarliestLocalOffset and TieredOffset
KIP-1017 Health check endpoint for Kafka Connect
KIP-1025 Optionally URL-encode clientID and clientSecret in authorization header
KIP-1031 Control offset translation in MirrorSourceConnector
KIP-1033 Add Kafka Streams exception handler for exceptions occurring during processing
KIP-1049 Add config log.summary.interval.ms to Kafka Streams
KIP-1057 Add remote log metadata flag to the dump log tool