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Connect your Apache Spark application with Azure Event Hubs

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This tutorial walks you through connecting your Spark application to Event Hubs for real-time streaming. This integration enables streaming without having to change your protocol clients, or run your own Kafka or Zookeeper clusters. This tutorial requires Apache Spark v2.4+ and Apache Kafka v2.0+.

Note

This sample is available on GitHub

In this tutorial, you learn how to:

  • Create an Event Hubs namespace
  • Clone the example project
  • Run Spark
  • Read from Event Hubs for Kafka
  • Write to Event Hubs for Kafka

Prerequisites

Before you start this tutorial, make sure that you have:

Note

The Spark-Kafka adapter was updated to support Kafka v2.0 as of Spark v2.4. In previous releases of Spark, the adapter supported Kafka v0.10 and later but relied specifically on Kafka v0.10 APIs. As Event Hubs for Kafka does not support Kafka v0.10, the Spark-Kafka adapters from versions of Spark prior to v2.4 are not supported by Event Hubs for Kafka Ecosystems.

Create an Event Hubs namespace

An Event Hubs namespace is required to send and receive from any Event Hubs service. See Creating an event hub for instructions to create a namespace and an event hub. Get the Event Hubs connection string and fully qualified domain name (FQDN) for later use. For instructions, see Get an Event Hubs connection string.

Clone the example project

Clone the Azure Event Hubs repository and navigate to the tutorials/spark subfolder:

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

Read from Event Hubs for Kafka

With a few configuration changes, you can start reading from Event Hubs for Kafka. Update BOOTSTRAP_SERVERS and EH_SASL with details from your namespace and you can start streaming with Event Hubs as you would with Kafka. For the full sample code, see sparkConsumer.scala file on the GitHub.

//Read from your Event Hub!
val df = spark.readStream
    .format("kafka")
    .option("subscribe", TOPIC)
    .option("kafka.bootstrap.servers", BOOTSTRAP_SERVERS)
    .option("kafka.sasl.mechanism", "PLAIN")
    .option("kafka.security.protocol", "SASL_SSL")
    .option("kafka.sasl.jaas.config", EH_SASL)
    .option("kafka.request.timeout.ms", "60000")
    .option("kafka.session.timeout.ms", "30000")
    .option("kafka.group.id", GROUP_ID)
    .option("failOnDataLoss", "true")
    .load()

//Use dataframe like normal (in this example, write to console)
val df_write = df.writeStream
    .outputMode("append")
    .format("console")
    .start()

If you receive an error similar to the following error, add .option("spark.streaming.kafka.allowNonConsecutiveOffsets", "true") to the spark.readStream call and try again.

IllegalArgumentException: requirement failed: Got wrong record for <spark job name> even after seeking to offset 4216 got offset 4217 instead. If this is a compacted topic, consider enabling spark.streaming.kafka.allowNonConsecutiveOffsets

Write to Event Hubs for Kafka

You can also write to Event Hubs the same way you write to Kafka. Don't forget to update your configuration to change BOOTSTRAP_SERVERS and EH_SASL with information from your Event Hubs namespace. For the full sample code, see sparkProducer.scala file on the GitHub.

df = /**Dataframe**/

//Write to your Event Hub!
df.writeStream
    .format("kafka")
    .option("topic", TOPIC)
    .option("kafka.bootstrap.servers", BOOTSTRAP_SERVERS)
    .option("kafka.sasl.mechanism", "PLAIN")
    .option("kafka.security.protocol", "SASL_SSL")
    .option("kafka.sasl.jaas.config", EH_SASL)
    .option("checkpointLocation", "./checkpoint")
    .start()

Next steps

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