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Using Akka Streams with Event Hubs for Apache Kafka

  • Article

This tutorial shows you how to connect Akka Streams through the Event Hubs support for Apache Kafka without changing your protocol clients or running your own clusters.

In this tutorial, you learn how to:

  • Create an Event Hubs namespace
  • Clone the example project
  • Run Akka Streams producer
  • Run Akka Streams consumer

Note

This sample is available on GitHub

Prerequisites

To complete this tutorial, make sure you have the following prerequisites:

  • Read through the Event Hubs for Apache Kafka article.
  • An Azure subscription. If you do not have one, create a free account before you begin.
  • Java Development Kit (JDK) 1.8+
    • On Ubuntu, run apt-get install default-jdk to install the JDK.
    • Be sure to set the JAVA_HOME environment variable to point to the folder where the JDK is installed.
  • Download and install a Maven binary archive
    • On Ubuntu, you can run apt-get install maven to install Maven.
  • Git
    • On Ubuntu, you can run sudo apt-get install git to install Git.

Create an Event Hubs namespace

An Event Hubs namespace is required to send or receive from any Event Hubs service. See Create an event hub for detailed information. Make sure to copy the Event Hubs connection string for later use.

Clone the example project

Now that you have a Event Hubs connection string, clone the Azure Event Hubs for Kafka repository and navigate to the akka subfolder:

git clone https://github.com/Azure/azure-event-hubs-for-kafka.git
cd azure-event-hubs-for-kafka/tutorials/akka/java

Run Akka Streams producer

Using the provided Akka Streams producer example, send messages to the Event Hubs service.

Provide an Event Hubs Kafka endpoint

Producer application.conf

Update the bootstrap.servers and sasl.jaas.config values in producer/src/main/resources/application.conf to direct the producer to the Event Hubs Kafka endpoint with the correct authentication.

akka.kafka.producer {
    #Akka Kafka producer properties can be defined here


    # Properties defined by org.apache.kafka.clients.producer.ProducerConfig
    # can be defined in this configuration section.
    kafka-clients {
        bootstrap.servers="{YOUR.EVENTHUBS.FQDN}:9093"
        sasl.mechanism=PLAIN
        security.protocol=SASL_SSL
        sasl.jaas.config="org.apache.kafka.common.security.plain.PlainLoginModule required username=\"$ConnectionString\" password=\"{YOUR.EVENTHUBS.CONNECTION.STRING}\";"
    }
}

Important

Replace {YOUR.EVENTHUBS.CONNECTION.STRING} with the connection string for your Event Hubs namespace. For instructions on getting the connection string, see Get an Event Hubs connection string. Here's an example configuration: sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username="$ConnectionString" password="Endpoint=sb://mynamespace.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=XXXXXXXXXXXXXXXX";

Run producer from the command line

To run the producer from the command line, generate the JAR and then run from within Maven (or generate the JAR using Maven, then run in Java by adding the necessary Kafka JAR(s) to the classpath):

mvn clean package
mvn exec:java -Dexec.mainClass="AkkaTestProducer"

The producer begins sending events to the event hub at topic test, and prints the events to stdout.

Run Akka Streams consumer

Using the provided consumer example, receive messages from the event hub.

Provide an Event Hubs Kafka endpoint

Consumer application.conf

Update the bootstrap.servers and sasl.jaas.config values in consumer/src/main/resources/application.conf to direct the consumer to the Event Hubs Kafka endpoint with the correct authentication.

akka.kafka.consumer {
    #Akka Kafka consumer properties defined here
    wakeup-timeout=60s

    # Properties defined by org.apache.kafka.clients.consumer.ConsumerConfig
    # defined in this configuration section.
    kafka-clients {
       request.timeout.ms=60000
       group.id=akka-example-consumer

       bootstrap.servers="{YOUR.EVENTHUBS.FQDN}:9093"
       sasl.mechanism=PLAIN
       security.protocol=SASL_SSL
       sasl.jaas.config="org.apache.kafka.common.security.plain.PlainLoginModule required username=\"$ConnectionString\" password=\"{YOUR.EVENTHUBS.CONNECTION.STRING}\";"
    }
}

Important

Replace {YOUR.EVENTHUBS.CONNECTION.STRING} with the connection string for your Event Hubs namespace. For instructions on getting the connection string, see Get an Event Hubs connection string. Here's an example configuration: sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username="$ConnectionString" password="Endpoint=sb://mynamespace.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=XXXXXXXXXXXXXXXX";

Run consumer from the command line

To run the consumer from the command line, generate the JAR and then run from within Maven (or generate the JAR using Maven, then run in Java by adding the necessary Kafka JAR(s) to the classpath):

mvn clean package
mvn exec:java -Dexec.mainClass="AkkaTestConsumer"

If the event hub has events (for instance, if your producer is also running), then the consumer begins receiving events from topic test.

Check out the Akka Streams Kafka Guide for more detailed information about Akka Streams.

Next steps

To learn more about Event Hubs for Kafka, see the following articles: