Create a MySQL (Debezium) Source Connector

You can use a MySQL (Debezium) Source connector to import a stream of changes from MySQL, AmazonRDS, and Amazon Aurora.

Prerequisites

  • A MySQL database that is accessible from the connector instance.

  • A MySQL user exists. This database user for the Debezium connector must have LOCK TABLES privileges. For details, see MySQL Creating a user.

  • A binlog must be enabled for the source MySQL cluster.

Limitations

  • Only JSON, CloudEvents or AVRO formats can be used as a a Kafka message key and value format.

  • The MySQL (Debezium) Source connector can work with only a single task at a time.

Create a MySQL (Debezium) Source connector

To create the MySQL (Debezium) Source connector:

  1. In Redpanda Cloud, click Connectors in the navigation menu, and then click Create Connector.

  2. Select Import from MySQL (Debezium).

  3. On the Create Connector page, specify the following required connector configuration options:

    Property name Property key Description

    Topic prefix

    topic.prefix

    A topic prefix that identifies and provides a namespace for the particular database server/cluster that is capturing changes. The topic prefix should be unique across all other connectors because it is used as a prefix for all Kafka topic names that receive events emitted by this connector. Only alphanumeric characters, hyphens, dots, and underscores are accepted.

    Hostname

    database.hostname

    A resolvable hostname or IP address of the MySQL database server.

    Port

    database.port

    Integer port number of the MySQL database server.

    User

    database.user

    Name of the MySQL user to be used when connecting to the MySQL database.

    Password

    database.password

    The password of the MySQL database user who will be connecting to the MySQL database.

    SSL mode

    database.ssl.mode

    Specifies whether to use an encrypted connection to the MySQL server. Select disable to use an unencrypted connection. Select 'preferred' to use an encrypted connection if the server supports secure connections. If the server does not support secure connections, falls back to an unencrypted connection. Select require to use a secure, or encrypted connection. If a secure connection cannot be established when required is selected, then the connector fails.

    Kafka message key format

    key.converter

    Format of the key in the Redpanda topic.

    Message key JSON contains schema

    key.converter.schemas.enable

    Enable to specify that the message key contains schema in the schema field.

    Kafka message value format

    value.converter

    Format of the value in the Redpanda topic.

    Message value JSON contains schema

    value.converter.schemas.enable

    Enable to specify that the message value contains schema in the schema field.

    Connector name

    name

    Globally-unique name to use for this connector.

  4. Click Next. Review the connector properties specified, then click Create.

Map data

Use Include databases, Include tables, and Include columns to define data mapping. Alternatively, use Exclude databases, Exclude tables, and Exclude columns.

Following is an example table in db database:

CREATE TABLE IF NOT EXISTS Persons
(
    Id        int PRIMARY KEY,
    FirstName varchar(255),
    LastName  varchar(255)
);
sql

The table has one record:

INSERT INTO Persons (FirstName, LastName) VALUES (1, 'Winnie', 'the Pooh');
sql

The connector configuration for the table:

column.include.list = db\\.Persons\\.(Id|FirstName|LastName)
table.include.list = db\\.Persons
database.include.list = db
topic.prefix = frommysql
bash

The connector configuration will create the Redpanda topic frommysql.db.Persons.

For Kafka message value format = JSON (org.apache.kafka.connect.json.JsonConverter), the connector produces JSON messages with a schema like the following:

{
   "payload": {
      "schema": {
         // schema definition
      },
      "payload": {
         "before": null,
         "after": {
            "Id": 1,
            "FirstName": "Winnie",
            "LastName": "the Pooh"
         },
         ...
      }
   },
   "encoding": "json",
   "schemaId": 0
}
json

For Kafka message value format = AVRO (io.confluent.connect.avro.AvroConverter), the connector creates a Schema Registry frommysql.db.Persons-value record and produces messages like the following:

{
   "payload": {
      "before": null,
      "after": {
         "mysql.db.Persons.Value": {
            "Id": 1,
            "FirstName": {
               "string": "Winnie"
            },
            "LastName": {
               "string": "the Pooh"
            }
         }
      },
      ...
   },
   "encoding": "avro",
   "schemaId": 2
}
js

For Kafka message value format = CloudEvents (io.debezium.converters.CloudEventsConverter), the connector uses JSON or AVRO data serializer.

  • For JSON data serializer, enable Message value CloudEvents JSON contains schema to include JSON schema in message

  • For AVRO data serializer, connector creates schema in Schema Registry and produces messages in CloudEvents data format.

Test the connection

After the connector is created:

  • Check the connector status and confirm that there are no errors in logs and in Redpanda Console.

  • Review the Redpanda topic to confirm that it contains the expected data.

Troubleshoot

If the connector configuration is invalid, an error appears upon clicking Finish. If the connector fails, check the error message or select Show Logs to view error details.

  • Topics not created by the connector

    Create the topic manually or let the connector create it by setting (use desired number of partitions and replication factor):

    Topic creation enabled: true
Topic creation partitions: 1
Topic creation replication factor: -1

    Or in JSON:

    "topic.creation.enable": true,
"topic.creation.default.partitions": "1",
"topic.creation.default.replication.factor": "-1"
    json

  • Connector requires binlog file 'mysql-bin-changelog.257116', but MySQL only has mysql-bin-changelog.257123

    Task threw an uncaught and unrecoverable exception. Task is being killed and will not recover until manually restarted"
Connector requires binlog file 'mysql-bin-changelog.257116', but MySQL only has mysql-bin-changelog.257123, mysql-bin-changelog.257124, mysql-bin-changelog.257125

    The connector needs a binlog file that was already purged. Change the Snapshot mode property from the default to when_needed.

Additional errors and corrective actions follow.

Message Action

Unable to connect: Public Key Retrieval is not allowed

Set Allow public key retrieval property to true.

Unable to connect: Communications link failure

Confirm that Hostname and Port are correct.

Access denied for user

Confirm that User and Password credentials are valid.

Caused by: io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException: Invalid schema Invalid namespace: from-mysql.db.Persons; error code: 422

The Schema Registry namespace is incorrect. Consider changing the Topic prefix value, remove unallowed characters.

Suggested reading