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Create a Debezium source connector from MongoDB to Apache Kafka®

Track and write MongoDB database changes to an Apache Kafka® topic in a standard format with the Debezium source connector, enabling transformation and access by multiple consumers using a MongoDB replica set or sharded cluster.


Breaking changes in Debezium 2.5

Debezium version 2.5 introduces significant changes to the connector's configuration and behavior. New setups defaults to version 2.5 while existing setups using version 1.9 remain on that version for stability. Test configurations with version 2.5 before upgrading. Review the specific changes to the MongoDB connector in Debezium 2.5. For help with upgrades or queries, contact Aiven support.


To configure a Debezium source connector for MongoDB, you need either an Aiven for Apache Kafka service with Apache Kafka Connect enabled or a dedicated Aiven for Apache Kafka Connect cluster.


You can view the full set of available parameters and configuration options in the connector's documentation.

Before you begin, gather the necessary information about your source MongoDB database:

  • MONGODB_HOST: The database hostname
  • MONGODB_PORT: The database port
  • MONGODB_USER: The database user to connect
  • MONGODB_PASSWORD: The database password for the MONGODB_USER
  • MONGODB_DATABASE_NAME: The database name to include in the replica
  • MONGODB_REPLICA_SET_NAME: The name of MongoDB's replica set
  • APACHE_KAFKA_HOST: The hostname of the Apache Kafka service, only needed when using Avro as data format
  • SCHEMA_REGISTRY_PORT: The Apache Kafka's schema registry port, only needed when using Avro as data format
  • SCHEMA_REGISTRY_USER: The Apache Kafka's schema registry username, only needed when using Avro as data format
  • SCHEMA_REGISTRY_PASSWORD: The Apache Kafka's schema registry user password, only needed when using Avro as data format

With Aiven for Apache Kafka, you can gather the necessary Apache Kafka details from the service's Overview page on the Aiven console or by using the avn service get command with the Aiven CLI.

Setup a MongoDB Debezium source connector with Aiven Console

The following example demonstrates how to setup a Debezium source connector for Apache Kafka to a MongoDB database using the Aiven Console.

Define a Kafka Connect configuration file

Create a configuration file named debezium_source_mongodb.json with the following connector configurations. While optional, creating this file helps you organize your settings in one place and copy/paste them into the Aiven Console later.

"connector.class": "io.debezium.connector.mongodb.MongoDbConnector",
"mongodb.user": "MONGODB_USER",
"mongodb.password": "MONGODB_PASSWORD",
"key.converter": "io.confluent.connect.avro.AvroConverter",
"key.converter.schema.registry.url": "https://APACHE_KAFKA_HOST:SCHEMA_REGISTRY_PORT",
"key.converter.basic.auth.credentials.source": "USER_INFO",
"value.converter": "io.confluent.connect.avro.AvroConverter",
"value.converter.schema.registry.url": "https://APACHE_KAFKA_HOST:SCHEMA_REGISTRY_PORT",
"value.converter.basic.auth.credentials.source": "USER_INFO",

The configuration file contains the following entries:

  • name: The connector name, replace CONNECTOR_NAME with the name you want to use for the connector

  • MONGODB_HOST, MONGODB_PORT, MONGODB_DATABASE_NAME, MONGODB_USER, MONGODB_PASSWORD and MONGODB_REPLICA_SET_NAME: Source database parameters collected in the prerequisite phase.

  • tasks.max: Maximum number of tasks to execute in parallel. By default this is 1, the connector can use at most 1 task for each collection defined. Replace NR_TASKS with the amount of parallel task based on the number of input collections.

  • key.converter and value.converter: Defines the messages data format in the Apache Kafka topic. The io.confluent.connect.avro.AvroConverter converter pushes messages in Avro format. To store the message schemas, Aiven's Karapace schema registry is used, specified by the schema.registry.url parameter and related credentials.


    The key.converter and value.converter sections are only needed when pushing data in Avro format. Otherwise, messages default to JSON format.

    The USER_INFO is not a placeholder and does not require any parameter substitution.

Create a Kafka Connect connector with the Aiven Console

To create a Kafka Connect connector, follow these steps:

  1. Log in to the Aiven Console.

  2. Select the Aiven for Apache Kafka® or Aiven for Apache Kafka Connect® service to define the connector.

  3. Select Connectors from the sidebar.

  4. Select Create New Connector, which is available only for services that have Apache Kafka Connect enabled.

  5. Select Debezium - MongoDB.

  6. In the Common tab, locate the Connector configuration text box and select on Edit.

  7. Paste the connector configuration (stored in the debezium_source_mongodb.json file) in the form.

  8. Select Apply.


    The Aiven Console reads through the configuration file and automatically populates the relevant UI fields. You can view and modify these fields across different tabs. Any change you make is reflected in JSON format within the Connector configuration text box.

  9. After all the settings are correctly configured, select Create new connector.


    With Aiven for Apache Kafka, topics are not created automatically. You have two options:

  10. Verify the connector status under the Connectors screen.

  11. Verify the presence of the data in the target Apache Kafka topic coming from the MySQL dataset. The topic name is equal to concatenation of the database and table name. To change the target table name, you can use Apache Kafka Connect RegexRouter transformation.

You can also create connectors using the Aiven CLI command.