Kafka Monitoring and Metrics Using JMX with Docker¶

You can monitor Confluent Platform deployments by using Java Management Extensions (JMX).

Configure Environment¶

To use JMX with Docker containers, set the following properties:

java.rmi.server.hostname=<JMX_HOSTNAME>
com.sun.management.jmxremote.local.only=false
com.sun.management.jmxremote.rmi.port=<JMX_PORT>
com.sun.management.jmxremote.port=<JMX_PORT>

Note about hostname:

The JMX client needs to be able to connect to java.rmi.server.hostname. The default for bridged network is the bridged IP so you will only be able to connect from another Docker container. For host network, this is the IP that the hostname on the host resolves to.

The hostname is set to hostname -i in the Docker container. If you have more than one network configured for the container, hostname -i gives you all the IPs, the default is to pick the first IP (or network).

Configure Security¶

To set security on JMX, you can follow the SSL and authentication sections in Monitoring and Management Using JMX Technology.

Configure Kafka and ZooKeeper¶

Settings¶

Use the following environment variables to configure JMX monitoring for Kafka and ZooKeeper.

KAFKA_JMX_PORT

JMX Port.

KAFKA_JMX_OPTS

JMX options. Use this variable to override the default JMX options. The default options are set as follows:

-Djava.rmi.server.hostname=127.0.0.1 -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.authenticate=false  -Dcom.sun.management.jmxremote.ssl=false

KAFKA_JMX_HOSTNAME

Hostname associated with locally created remote objects.

Launching Kafka and ZooKeeper with JMX Enabled¶

The steps for launching Kafka and ZooKeeper with JMX enabled are the same as shown in the Quick Start for Confluent Platform, with the only difference being that you set KAFKA_JMX_PORT and KAFKA_JMX_HOSTNAME for both. Here are examples of the Docker run commands for each service:

docker run -d \
  --name=zk-jmx \
  --net=host \
  -e ZOOKEEPER_TICK_TIME=2000 \
  -e ZOOKEEPER_CLIENT_PORT=32181 \
  -e KAFKA_JMX_PORT=39999 \
  confluentinc/cp-zookeeper:7.2.12

docker run -d \
  --name=kafka-jmx \
  --net=host \
  -e KAFKA_BROKER_ID=1 \
  -e KAFKA_ZOOKEEPER_CONNECT=localhost:32181/jmx \
  -e KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://localhost:39092 \
  -e KAFKA_JMX_PORT=49999 \
  -e KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1 \
  confluentinc/cp-kafka:7.2.12

Configure other Confluent Platform components¶

Authentication is disabled for JMX by default in Kafka. The default JMX configuration binds an unauthenticated JMX interface to all network interfaces. You must use environment variables to override this default.

Use the following environment variables to override the default JMX options for Confluent Platform components.

Component	Environment Variable
Confluent Control Center	CONTROL_CENTER_JMX_OPTS
REST Proxy	KAFKAREST_JMX_OPTS
ksqlDB	KSQL_JMX_OPTS
Rebalancer	REBALANCER_JMX_OPTS
Schema Registry	SCHEMA_REGISTRY_JMX_OPTS