What is Debezium?

Debezium is a distributed platform for change data capture (CDC). It provides a set of connectors for various database systems (MySQL, PostgreSQL, MongoDB, Kafka, and others) that monitor changes (inserts, updates, deletes) in these databases and publish them as event streams in Apache Kafka.

Key components and features:

• Connectors: Specific to each database and use native CDC mechanisms (e.g., MySQL binary logs, PostgreSQL write-ahead logs).
• Apache Kafka: Used as the transport layer for event streams. Each data change is transformed into a Kafka message.
• Message format: Debezium uses a standardized message format that includes the old and new state of the changed row, the operation type (create, update, delete), and metadata.
• Guaranteed delivery: Ensures all changes are delivered in the correct order.
• Snapshots: Allows performing an initial snapshot of the database state when the connector starts.
• Change event format: Allows configuring the message format.

Use cases:

• Data replication: Creating up-to-date copies of data in other systems.
• Updating search indexes: Automatic updating of Elasticsearch or Solr when changes occur in the database.
• Microservices: Data exchange between microservices via events instead of direct API calls or shared databases.
• Audit: Creating logs of data changes.
• Event sourcing: Building a system where the application's state is determined by a sequence of events.

# Example of a basic Debezium Source Connector configuration for PostgreSQL
apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaConnector
metadata:
  name: debezium-source-connector
  labels:
    strimzi.io/cluster: my-kafka-cluster
spec:
  class: io.debezium.connector.postgresql.PostgresConnector
  tasksMax: 1
  config:
    database.hostname: postgresql
    database.port: 5432
    database.user: myuser
    database.password: mypassword
    database.dbname: mydb
    database.server.name: my-server
    plugin.name: pgoutput
    slot.name: debezium_slot
    topic.prefix: my-app