Tell about your experience working with Kafka: how did you monitor the cluster, what consensus mechanism was used?

In working with Kafka, I used several approaches for cluster monitoring:

• Using monitoring tools such as Prometheus and Grafana to track performance metrics, delays, and broker status.
• Setting up alerts based on key metrics (e.g., consumer lag, broker status).
• Using Kafka Manager or Confluent Control Center for visual cluster status monitoring.

For coordination and state management in a Kafka cluster, the Zookeeper mechanism is used, which provides coordination and metadata storage. In newer Kafka versions, it gradually transitions to its own KRaft (Kafka Raft) mechanism, replacing Zookeeper for cluster management.

An example of consumer lag monitoring with Prometheus:

- job_name: 'kafka_consumer'
  static_configs:
    - targets: ['kafka-broker1:9092']

Thus, monitoring and coordination ensure stable operation and high availability of the Kafka cluster.