Health checker for Kafka brokers and clusters that operates by

• inserting a message in a dedicated health check topic and waiting for it to become available on the consumer side,
• checking whether the broker is in the in-sync replica set for all partitions it replicates,
• checking whether under-repicated partitions exist, and
• checking whether offline partitions exist.

kafka-health-check usage:
  -broker-id uint
    	id of the Kafka broker to health check (default 0)
  -broker-port uint
    	Kafka broker port (default 9092)
  -check-interval duration
    	how frequently to perform health checks (default 10s)
  -no-topic-creation
    	disable automatic topic creation and deletion.
  -server-port uint
    	port to open for http health status queries (default 8000)
  -topic string
    	name of the topic to use - use one per broker, defaults to broker-<id>-health-check
  -zookeeper string
    	ZooKeeper connect string (e.g. node1:2181,node2:2181,.../chroot)

Broker health can be queried at /:

$ curl -s localhost:8000/
sync

Return codes and response bodies are:

• 200 with sync for a healthy broker that is fully in sync with all leaders.
• 200 with imok for a healthy broker that replays messages of its health check topic, but is not fully in sync.
• 500 with nook for an unhealthy broker that fails to replay messages in its health check topic within 100 milliseconds.

Cluster health can be queried at /cluster:

$ curl -s localhost:8000/cluster
green

Return codes and response bodies are:

• 200 with green if all replicas of all partitions of all topics are in sync.
• 200 with yellow if one or more partitions are under-replicated.
• 500 with red if one or more partitions are offline.

Tested with the following Kafka versions:

• 0.10.0.1
• 0.10.0.0
• 0.9.0.1
• 0.9.0.0

Kafka 0.8 is not supported.

see the compatibility spec for the full list of executed compatibility checks. To execute the compatibility checks, run make compatibility. Running the checks require Docker.

Run make to build after running make deps to restore the dependencies using govendor.

• Make to run the Makefile
• Go 1.6 since it's written in Go

• When first started, the checker tries to find the Kafka broker to check in the cluster metadata. Then, it tries to find the health check topic, and creates it if missing by communicating directly with ZooKeeper(configuration: 10 seconds message lifetime, one single partition assigned to the broker to check). This behavior can be disabled by using -no-topic-creation.
• When shutting down, the checker deletes to health check topic partition by communicating directly with ZooKeeper. This behavior can be disabled by using -no-topic-creation.
• The check will try to create the health check topic only on its first connection after startup. If the topic disappears later while the check is running, it will not try to re-create its health check topic.
• If the broker health check fails, the cluster health will be set to red.