Monitoring

Using JMX

For JMX to work with docker containers, the following properties must be set:

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 that one network configured for the container, hostname -i gives you all the IPs, the default is to pick the first IP (or network).

Security on JMX

To set security on JMX, you can follow the SSL and authentication sections in this guide: https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html

Kafka & Zookeeper

Settings

KAFKA_JMX_PORT
JMX Port.
KAFKA_JMX_OPTS
JMX options.
KAFKA_JMX_HOSTNAME

hostname associated with locally created remote objects.

The default setting is 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

Launching Kafka and Zookeeper with JMX Enabled

The steps for launching Kafka and Zookeeper with JMX enabled are the same as we saw in the quickstart guide, 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 \
  -e KAFKA_JMX_HOSTNAME=`docker-machine ip confluent`
  confluentinc/cp-zookeeper:3.2.0

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_JMX_HOSTNAME=`docker-machine ip confluent`
  confluentinc/cp-kafka:3.2.0

Note: in the KAFKA_JMX_HOSTNAME environment variable example above, it assumes you have a docker machine named “Confluent”. You should substitute with your docker machine name where appropriate.