# Monitor and Track Metrics in Docker with JMX in Confluent Platform You can monitor Confluent Platform deployments by using Java Management Extensions (JMX) and MBeans. #### NOTE Confluent offers some alternatives to using JMX monitoring. - **Health+**: Consider monitoring and managing your environment with [Monitor Confluent Platform with Health+](../../../health-plus/index.md#health-plus). Ensure the health of your clusters and minimize business disruption with intelligent alerts, monitoring, and proactive support based on best practices created by the inventors of Kafka. - **Confluent Control Center**: You can deploy [Confluent Control Center](/control-center/current/overview.html) for out-of-the-box Kafka cluster monitoring so you don’t have to build your own monitoring system. ## Configure JMX environment variables JMX is enabled for Apache Kafka® by default. To expose JMX on a Kafka container, set `KAFKA_JMX_PORT` and `KAFKA_JMX_HOSTNAME` in your Compose file, Dockerfile, or `docker run` command. For a complete example, see [Run Kafka with JMX enabled](#start-kafka-docker). `KAFKA_JMX_PORT` : The JMX Port. `KAFKA_JMX_HOSTNAME` : The hostname associated with locally created remote objects. `KAFKA_JMX_OPTS` : JMX options. Use this variable to override the default JMX options such as whether authentication is enabled. A JMX client must be able to connect to the `java.rmi.server.hostname` specified in the `KAFKA_JMX_OPTS`.
The default options are set as follows:
```bash -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 ```
The default for a bridged network is the bridged IP address, which means that you can only connect to it from another Docker container. For the host network, this is the IP that the hostname on the host resolves to. Use `hostname -i` to see what the hostname is set to in the Docker container. If you have more than one network configured for the container, `hostname -i` gives you all the IPs, and the default is the first IP address. ## Available JMX MBeans For the list of JMX MBeans you can monitor on Kafka, see [Monitor Kafka with JMX in Confluent Platform](../../../kafka/monitoring.md#kafka-monitoring). ## Configure security Password authentication and TLS/SSL are disabled for JMX by default in Kafka, however in a production environment, you should enable authentication and TLS/SSL to prevent unauthorized users from accessing your brokers. You override the default JMX settings to enable authentication and SSL. To learn about how to secure JMX, follow the TLS/SSL and authentication sections in [Monitoring and Management Using JMX Technology](https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html). ## Run Kafka with JMX enabled To expose JMX on a Kafka container, add `KAFKA_JMX_PORT` and `KAFKA_JMX_HOSTNAME` to your `docker run` command or Compose file. The following Docker `run` command starts Kafka with JMX configured: ```bash docker run -d \ --name=kafka-jmx \ -h kafka-jmx \ -p 9101:9101 \ -e KAFKA_NODE_ID=1 \ -e KAFKA_LISTENER_SECURITY_PROTOCOL_MAP='CONTROLLER:PLAINTEXT,PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT' \ -e KAFKA_ADVERTISED_LISTENERS='PLAINTEXT://kafka-jmx:29092,PLAINTEXT_HOST://localhost:9092' \ -e KAFKA_JMX_PORT=9101 \ -e KAFKA_JMX_HOSTNAME=localhost \ -e KAFKA_PROCESS_ROLES='broker,controller' \ -e KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1 \ -e KAFKA_CONTROLLER_QUORUM_VOTERS='1@kafka-jmx:29093' \ -e KAFKA_LISTENERS='PLAINTEXT://kafka-jmx:29092,CONTROLLER://kafka-jmx:29093,PLAINTEXT_HOST://0.0.0.0:9092' \ -e KAFKA_INTER_BROKER_LISTENER_NAME='PLAINTEXT' \ -e KAFKA_CONTROLLER_LISTENER_NAMES='CONTROLLER' \ -e CLUSTER_ID='MkU3OEVBNTcwNTJENDM2Qk' \ confluentinc/cp-kafka:8.3.1 ``` ## View MBeans with JConsole To confirm you have successfully configured JMX monitoring with a Docker container, you can start [JConsole](https://docs.oracle.com/javase/8/docs/technotes/guides/management/jconsole.html), a command-line utility provided with Java. To start JConsole, use the `jconsole` command, and connect to the Kafka process. For this example, the JMX settings for a Docker container running locally might look like the following: ```bash KAFKA_JMX_PORT: 9101 KAFKA_JMX_HOSTNAME: localhost ``` After JConsole starts, under **Remote Process**, enter the hostname and port you specified in your JMX configuration, and click **Connect**.  If you have not configured authentication, you may be prompted to make an **Insecure connection**.  After JConsole is running, you can select the **MBeans** tab and expand the folders to see the JMX events and attributes for those events.  ## Configure other Confluent Platform components Use the following environment variables to override the default JMX options such as authentication settings for other 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 | ## Related content - [Install Confluent Platform Using Docker](../installation.md#cpdocker-intro) - [Docker Image Reference for Confluent Platform](../image-reference.md#image-reference) - [Configure Kafka Logs for Docker in Confluent Platform](logging.md#docker-operations-logging) - [Mount Docker External Volumes in Confluent Platform](external-volumes.md#external-volumes)