CMAK: Cluster Manager for Apache Kafka

CMAK (Cluster Manager for Apache Kafka) is an open-source tool providing a web-based management interface for Apache Kafka clusters. Originally released as Kafka Manager by Yahoo and later renamed CMAK, it has become one of the most widely adopted utilities for teams operating Kafka in production environments.

It surfaces cluster topology, topic configuration, partition assignments, broker health, and consumer group state through a browser UI. Instead of running individual CLI commands to inspect and modify cluster state, operators get a single dashboard that covers the information needed to manage Kafka deployments day to day. Teams managing event-driven and streaming infrastructure use it to reduce operational overhead without introducing proprietary tooling.

CMAK supports the full lifecycle of Kafka topic management: creating topics with custom partition counts and replication factors, modifying retention settings, and deleting obsolete topics. Partition reassignment is available through the UI, allowing operators to rebalance load across brokers when cluster topology changes without taking clusters offline.

Broker management surfaces the current state of each broker, including configuration and the partitions it is currently leading. This visibility is essential for capacity planning and identifying imbalanced load distributions before they affect throughput or latency.

Consumer group monitoring is one of the most operationally critical views in CMAK. It displays current offsets, committed offsets, and consumer lag for each partition across all active consumer groups. Persistent or growing lag is typically the first signal of a downstream processing bottleneck, and having this visible in a dashboard rather than requiring CLI queries speeds up incident detection significantly.

Consumer group details also show which consumers are actively connected and which partitions they hold, supporting both debugging and capacity planning for consumer scaling decisions. Engineering teams running high-throughput data pipelines as part of a software engineering engagement commonly use CMAK as the primary operational interface for their Kafka infrastructure.

CMAK integrates with Prometheus and Grafana for metric collection and visualization, allowing teams to extend its operational views with alerting rules and long-term trend dashboards. Datadog and other APM platforms can also pull Kafka metrics alongside CMAK for a unified observability picture.

Because CMAK is a standard web application, it sits naturally behind an identity provider for SSO access control, and its RBAC model governs which operations each user can perform within the Kafka environment. This makes it suitable for shared engineering environments where multiple teams need visibility without unrestricted cluster access.

CMAK is released under Apache License 2.0, permitting free use, modification, and redistribution in both open-source and commercial projects. It is maintained on GitHub with periodic updates from the contributor community.

CMAK is designed for ZooKeeper-based Kafka deployments. Organisations that have migrated to KRaft mode (Kafka without ZooKeeper, available from Kafka 3.3 onwards) should evaluate whether CMAK's ZooKeeper dependency aligns with their cluster configuration before adopting it as their primary management tool.