Home icon

Announcing in-place ZooKeeper-to-KRaft cluster upgrades for Amazon MSK

Big Data Blog

This article announces in-place ZooKeeper-to-KRaft cluster upgrades for Amazon MSK, preparing existing clusters for Apache Kafka 4.0 which removes ZooKeeper support.

  • Upgrade from ZooKeeper to KRaft metadata mode using the standard version upgrade workflow
  • Clusters must run Kafka 3.9.x in ZooKeeper mode; earlier versions require standard upgrade first
  • Clients must use bootstrap.servers only; ZooKeeper connection strings must be removed before upgrade
  • Multi-phase migration includes controller bootstrap, metadata migration, broker transition, validation, and ZooKeeper decommissioning
  • Cluster remains available for produce/consume traffic with no expected downtime following best practices
  • Built-in recovery automatically reverts to pre-migration state if issues detected
  • Standard brokers require three Availability Zones and ZooKeeper access disabled before upgrade
  • ZooKeeper-specific CloudWatch metrics become unavailable after migration

The in-place upgrade provides a streamlined path for Amazon MSK customers to modernize their clusters and prepare for future Kafka releases with enhanced scalability and resilience.

Go to article

The AWS News Feed is currently looking for gold sponsors. If you want to support the AWS community and reach a large audience of AWS professionals, consider sponsoring the AWS News Feed.

Related articles

Aug 26
2026
Migrate an OAuth 2.0 authenticated Apache Kafka cluster to Amazon MSK with MSK Replicator
Aug 17
2026
Amazon MSK now supports configuring custom domain names for MSK Provisioned clusters
May 29
2024
Amazon MSK launches support for KRaft mode for new Apache Kafka clusters
Aug 25
2026
MSK Replicator now supports OAuth 2.0 (SASL/OAUTHBEARER) authentication for replication from external Apache Kafka clusters to Amazon MSK

The AWS News Feed is currently looking for silver sponsors. If you want to support the AWS community and reach a large audience of AWS professionals, consider sponsoring the AWS News Feed.