Move data by using a Kafka connector

Apache Kafka is a popular distributed streaming platform that allows you to publish and subscribe to streams of records in a fault-tolerant way. Microsoft Azure offers a seamless integration with Kafka through the Kafka Connect feature. In this article, we will explore how to move data using a Kafka connector in the context of designing and implementing native applications using Azure Cosmos DB.

Setting Up Kafka Cluster and Azure Cosmos DB Account

To start moving data from Kafka to Azure Cosmos DB, we need to set up a Kafka cluster and an Azure Cosmos DB account. Follow the documentation on how to provision a Kafka cluster and an Azure Cosmos DB account with the desired API.

Configuring the Kafka Connector

Once you have your Kafka cluster and Azure Cosmos DB account ready, you can proceed with configuring the Kafka connector to move data between the two. Begin by creating a Kafka topic where you can publish the records you want to push to Azure Cosmos DB. Use the Kafka producer API or any other Kafka-compatible tool to produce records into this topic.

Next, you need to install and configure the Kafka Connect Azure Cosmos DB Sink connector. This connector will be responsible for taking the records from the Kafka topic and inserting them into Azure Cosmos DB. Start by downloading and extracting the connector package from the Confluent Hub website.

Open a terminal window and navigate to the extracted directory. As the next step, create a configuration file for the connector. Here’s an example of a configuration file for the Azure Cosmos DB Sink connector:

name=sink-connector
connector.class=com.azure.cosmos.kafka.connect.sink.CosmosDBSinkConnector
topics=kafka-topic
tasks.max=1
key.converter=org.apache.kafka.connect.storage.StringConverter
value.converter=org.apache.kafka.connect.json.JsonConverter
value.converter.schemas.enable=false
cosmos.connection.endpoint=https://your-cosmos-host.documents.azure.com:443/
cosmos.connection.key=your-cosmos-access-key
cosmos.database=your-cosmos-database
cosmos.collection=your-cosmos-collection

In this configuration file, you need to replace the placeholders with the appropriate values for your environment. Ensure that you provide the correct endpoint URL and access key for your Azure Cosmos DB account. Specify the Kafka topic you created earlier in the topics property. You can also customize the number of tasks (parallelism) based on your requirements.

Save the configuration file as cosmos-sink.properties. Now, start the Kafka Connect distributed worker by running the following command:

./bin/connect-distributed.sh ./etc/schema-registry/connect-avro-standalone.properties

The Kafka Connect worker will start up and read the cosmos-sink.properties file. It will load the Azure Cosmos DB Sink connector with the specified configuration. The connector will listen to the Kafka topic and start moving the records to Azure Cosmos DB.

Verifying the Data Flow

Verify that the data is successfully streaming from Kafka to Azure Cosmos DB by querying your Azure Cosmos DB account. You should see the records inserted into the specified database and collection.

By leveraging the Kafka Connect feature in Azure, you can seamlessly move data from your Kafka cluster to Azure Cosmos DB without writing any application code. This approach allows you to decouple your data ingestion pipeline and take advantage of the scalability and reliability of both Kafka and Azure Cosmos DB.

In this article, we explored the process of moving data from Kafka to Azure Cosmos DB using a Kafka connector. We discussed the steps involved, including setting up a Kafka cluster, configuring the Kafka Connect Azure Cosmos DB Sink connector, and verifying the data flow. To learn more about designing and implementing native applications using Microsoft Azure Cosmos DB, refer to the official Microsoft documentation.