As an example, to set kafkastore.connection.url, host.name, listeners and debug youd run the following: SCHEMA_REGISTRY_KAFKASTORE_CONNECTION_URL. The image will then convert these environment variables to corresponding Connect config variables. A unique string that identifies the Connect cluster group this worker belongs to. Process the input data with Kafka Streams, Running further Confluent demo applications for the Kafka Streams API, Upgrading from CP 3.3.x (Kafka 0.11.0.x-cp1) to CP 4.0.0 (Kafka 1.0.0-cp1), Upgrading older Kafka Streams applications to CP 4.0.0, Confluent Support Metrics (add-on package). This section provides an overview of Confluents Docker images for the Confluent Platform. The images are available for Confluent Platform 3.0.1 and greater. Also notice that we set KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR to 1. As an example, to set broker.id, advertised.listeners, zookeeper.connect, offsets.topic.replication.factor, and confluent.support.customer.id youd run the following command: If you want to enable Proactive support or use Confluent Auto Data Balancing features, please follow the Proactive support and ADB documentation at Confluent documentation. Advertised listeners is how it gives out a host name that can be reached by the client. This ensures that the containers will retain their proper state when stopped and restarted.
Furthermore, it can add a network hop and may not be as performant as the host network, which shares the network stack. This must be the same for all workers with the same, The name of the topic in which to store offset data for connectors. How can I use plain JSON data with Connect? Hostname must be resolveable because slave nodes serve registration requests indirectly by simply forwarding them to the current master, and returning the response supplied by the master. Advertised host name is how Connect gives out a host name that can be reached by the client. In summary, host networking is the recommended option in the following cases: Docker containers should be launched with Restart=always unless you are using a process manager.
Images are available on DockerHub for each component of the Confluent Platform. For a full list of all available configuration options for each Confluent Platform component, you should refer to their respective documentation. Tells ZooKeeper where to listen for connections by clients such as Kafka. What is included in the Confluent Platform? The following settings must be passed to run the Confluent Control Center image. Please report any inaccuracies on this page or suggest an edit. Alternatively, the source files for the images are available on Github if you would prefer to extend and/or rebuild the images and upload them to your own DockerHub repository. If so the consumer should use the same chroot path in its connection string. This is an important setting, as it will make Kafka accessible from outside the container by advertising its location on the Docker host. That package enables the deployed connectors to collect the metrics visualized in Confluent Control Center. The ZooKeeper image uses variables prefixed with ZOOKEEPER_ with the variables expressed exactly as they would appear in the zookeeper.properties file. Hostname is required because it defaults to the Java canonical host name for the container, which may not always be resolvable in a Docker environment. We recommend that you bind this to a volume on the host machine so that data is persisted across runs. This must be the same for all workers with the same, The name of the topic in which to store state for connectors. For more details, please refer to the Confluent Platform documentation on. Note: The Kafka Connect image is labeled as Enterprise simply because it contains the Confluent Control Center package. To expose Kafka to clients outside of the bridge network, you need to find the container IP and put it in advertised.listeners. This ensures that intermittent failures in the Docker environment do not result in unnecessary failures of the Confluent services. Sets the server ID in the. "connector.class":"io.confluent.connect.replicator.ReplicatorSourceConnector". 
For more information, please refer to the Schema Registry documentation on, The host name used to generate absolute URLs in responses. Hostname is required because it defaults to the Java canonical host name for the container, which may not always be resolvable in a Docker environment. The table below lists the available images and the Confluent software packages they contain. 
Only required when running in clustered mode. The other images maintain their state directly in Kafka topics, so mounted volumes are not usually required for those containers. This can be difficult to achieve depending on how youre using the images. Do I need to write custom code to use Kafka Connect? Why is CPU usage high for my Connect worker when no connectors have been deployed? Enabling or disabling the Metrics feature, Recommended Proactive Support configuration settings for licensed Confluent customers, Sharing Proactive Support Metadata with Confluent manually, Configuring Kafka Connect with External Jars, Confluent Enterprise Kafka (cp-enterprise-kafka), Multi-host clusters without using Swarm/Kubernetes host network is the best approach, If you need clients to be able to access Kafka outside the bridge/overlay network, Build a new Docker image that has the connector installed. The server may also have a ZooKeeper chroot path as part of its ZooKeeper connection string which puts its data under some path in the global ZooKeeper namespace. This is needed when you are running with a single-node cluster.
File descriptor limit: Control Center may require many open files so we recommend setting the file descriptor limit to at least 16384. If you dont want to create a new Docker image, please see our documentation on, Confluent Control Center with Security Enabled.
We recommend setting this to 3 in a production environment. We do not recommend using these images with Docker for Mac at this time. This makes it difficult to access the containerized cluster with client applications running directly on the Mac. For the Kafka REST Proxy image use variables prefixed with KAFKA_REST_ with an underscore (_) separating each word instead of periods. "key.converter": "io.confluent.connect.replicator.util.ByteArrayConverter".
Why should I use distributed mode instead of standalone? After testing a connector in standalone mode, restarting it doesnt write the data again? This controls the format of the data that will be written to Kafka for source connectors or read from Kafka for sink connectors. This must be the same for all workers with the same. More specifically, we use the Docker -e or --env flags for setting various settings in the respective images when starting up the images. This field is always required. As an example, to set broker.id, advertised.listeners, zookeeper.connect, and offsets.topic.replication.factor, youd run the following command: Youll notice that we set the KAFKA_ADVERTISED_LISTENERS variable to localhost:29092. For example, if you need to set ssl.key.password, the environment variable name would be CONNECT_SSL_KEY_PASSWORD. Can I use a newer version of connect with older brokers? a custom client? As an example, to set the required properties like bootstrap.servers, the topic names for config, offsets and status as well the key or value converter, run the following command: The following settings must be passed to run the Kafka Connect Docker image. The images are not currently tested on Docker Swarm. The Enterprise Kafka image uses variables prefixed with KAFKA_ for Apache Kafka and with CONFLUENT_ for Confluent components. The Confluent Control Center image uses variables prefixed with CONTROL_CENTER_ with an underscore (_) separating each word instead of periods. with _, converting the resulting string to uppercase and prefixing it with CONNECT_. Does source connector X support output format Y? As an example, to set the listeners, schema.registry.url and zookeeper.connect youd run the following command: The following settings must be passed to run the REST Proxy Docker image. Is the Schema Registry a required service to run Kafka Connect? Converter class for values. "src.zookeeper.connect": "zookeeper-src:2181".
You can install the Confluent Platform using Docker images. We have outlined those variables below for each component along with an example of how to pass them. There are currently two ways to add new connectors to the Kafka Connect image. "dest.zookeeper.connect": "zookeeper-dest:2181", "topic.rename.format": "${topic}.replica"}}'. Can connect sink connectors read data written by other clients, e.g. Make sure to set this if running Schema Registry with multiple nodes. To enable Control Center to interact with a Kafka Connect cluster, set this parameter to the REST endpoint URL for the Kafka Connect cluster. Other JDKs (including Oracle Java) are supported, but you must extend the images yourself to implement that change. In a Docker environment, you will need to make sure that your clients can connect to Kafka and other services. The Kafka Connect image uses variables prefixed with CONNECT_ with an underscore (_) separating each word instead of periods. Converter class for internal keys that implements the, Converter class for internal values that implements the. Adding Connectors to the Kafka Connect Image. Get an overview of an Apache Kafka-centric microservices architecture. Get early-bird pricing for Kafka Summit London, April 23-24, 2018. hostname1:port1,hostname2:port2,hostname3:port3/chroot/path, "org.apache.kafka.connect.json.JsonConverter", hostname1:port1,hostname2:port2,hostname3:port3. "src.kafka.bootstrap.servers": "kafka-src:9082". Converter class for keys. For example to give a chroot path of /chroot/path you would give the connection string as hostname1:port1,hostname2:port2,hostname3:port3/chroot/path. Which metadata and data is not being collected? This controls the format of the data that will be written to Kafka for source connectors or read from Kafka for sink connectors. The Enterprise Kafka image includes the packages for Confluent Auto Data Balancing and Proactive support in addition to Kafka. Specifies the ZooKeeper connection string in the form hostname:port where host and port are the host and port of a ZooKeeper server. The following features/environments are not currently tested: Some configuration variables are required when starting up the Docker images.
The Confluent Platform Docker images support passing configuration variables dynamically using environment variables. Youll note that some images are identified as `cp-enterprise-${component_name}`. In a Docker environment, you will need to make sure that your clients can connect to Connect and other services. Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down). You can follow the examples found in, Add the connector jars via volumes. The client will make use of all servers irrespective of which servers are specified here for bootstrapping; this list only impacts the initial hosts used to discover the full set of servers. "value.converter": "io.confluent.connect.replicator.util.ByteArrayConverter". More details on these issues can be found at: When deploying the Kafka and ZooKeeper images, you should always use mounted volumes for the file systems those images use for their persistent data. The following settings must be passed to run the Kafka Connect Docker image: Copyright 2018, Confluent, Inc. All other trademarks, servicemarks, and copyrights are the property of their respective owners. If you have three or more nodes, you do not need to change this from the default. Confluent Kafka Replicator is a Kafka connector and runs on a Kafka Connect cluster. Data persistence: the Control Center image stores its data in the /var/lib/confluent-control-center directory. To allow connecting through other ZooKeeper nodes when that ZooKeeper machine is down you can also specify multiple hosts in the form hostname1:port1,hostname2:port2,hostname3:port3. The Confluent Docker images are tested and shipped with Azul Zulu OpenJDK. These images include proprietary components that must be licensed from Confluent when deployed. As an example, to set clientPort, tickTime, and syncLimit run the command below: The Kafka image uses variables prefixed with KAFKA_ with an underscore (_) separating each word instead of periods. As an example, the following command runs Control Center, passing in its ZooKeeper, Kafka, and Connect configuration parameters.
Installing Control Center on Apache Kafka, Install and Configure Kafka Connect Cluster for Replicator, Configure and run a Confluent Replicator on the Connect Cluster, Getting More Throughput From Replicator Tasks, Comparing Mirror Maker to Confluent Replicator, Migration from Zookeeper master election to Kafka master election, Security: Data Volumes for Configuring Secrets, Modifying SASL mechanisms in a Running Cluster, Required ACL setting for secure Kafka clusters. The host name advertised in ZooKeeper. No explicit license is required when using the Kafka Connect image on its own. The name of the topic in which to store connector and task configuration data. Why does a connector configuration update trigger a task rebalance?
Tells Kafka how to get in touch with ZooKeeper. For the Schema Registry image, use variables prefixed with SCHEMA_REGISTRY_ with an underscore (_) separating each word instead of periods. All other settings for Connect like security, monitoring interceptors, producer and consumer overrides can be passed to the Docker images as environment variables. The names of these environment variables are derived by replacing . The primary reason is that Docker for Mac does not update the local /etc/hosts file with the hostnames of the deployed containers. Advertised host name is required for starting up the Docker image because it is important to think through how other clients are going to connect to Connect REST API. Learn about KSQL, Streaming SQL for Apache Kafka and what it can do. Bridge networking is currently only supported on a single host. A list of host/port pairs to use for establishing the initial connection to the Kafka cluster. The image uses variables prefixed with CONNECT_ with an underscore (_) separating each word instead of periods. These variables have an underscore (_) separating each word instead of periods. Additionally, the semantics of --net=host are not clear, so deploying containers with host networking on Docker for Mac is not reliable. How do I change the output data format of a SinkConnector? Replication factor for Control Center topics. Advertised listeners is required for starting up the Docker image because it is important to think through how other clients are going to connect to kafka. As an example, to set the required properties like bootstrap.servers, the topic names for config, offsets and status as well the key or value converter, run the following command: The following example shows how to create a Confluent Kafka Replicator connector which replicates topic confluent from source Kafka cluster (src) to a destination Kafka cluster (dest). For multiple hosts, you will need to use overlay networks which are not currently supported.
