Debezium-demo project

This project offers a sandbox for playing around with debezium. It offers a basic database with some data records and some sample configuration files.

Feel free to play around with all features that debezium offers.

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Pre requisits

For using that demo it is necessary to have the following things pre setup:

1. you need to have docker-compose installed
2. if you want to see the kafka messages in a convenient way it is also preferred you have kafka installed on your machine
3. if you like to have a proper console output you should also install jq

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How to start the demo

Just start the docker-compose file and all necessary containers will boot up :

docker-compose up

On the database execute the databasefiles/sonic_chars_schema.sql to create the schema in the database. All other sql-files are then for testing purpose. You can also execute them to see Debezium's snapshot behaviour when you upload the connector, or you can execute them later to see the change capturing in the kafka broker.

Also, feel free to add additional datarecords and play around with updates, deletions, inserts to get a full experience on how those transactions are captured.

Interact with Kafka Connect instance with the helperfiles

In the connect-helper folder you can find some useful shells to quickly interact with the kafka-connect instance.

• get-connectors: get a list of all connectors
• get-connector-details connector-name : get the currently uploaded detail configuration of a connector
• get-connector-status connector-name : get the status of a connector
• upload-connector file-to-upload: uploads a file to the kafka-connect
• delete-connector connector-name: deletes a connection by using the connector name also listed with get_connectors

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Visualization with Kafka UI

With the docker-compose file there is also a Kafka-UI image starting up. On http://localhost:8005 you have a Web UI showing you all important information like schemas, connector status, topics etc.

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Upload a Connector configuration

The default way to upload a connector configuration is to use curl.

curl -i -X POST -H "Accept:application/json" -H  "Content-Type:application/json" http://localhost:8083/connectors/ -d @your-file.json

For a simple test you can use one of the configuration files that are in the example directory.

Using the helper shell

If you want to use the project's shell commands you can upload a configuration by doing

connect-helper/upload-connector <your_file>

You can check the success of the upload using the browser and go to

http://localhost:8083/connectors

and see if the connector is in the list.

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Consume Kafka messages

Within the docker container

You need another terminal to start consuming kafka messages. With the following command you get into the Docker container:

docker exec -it docker_kafka_1 bash

In the interactive shell of the docker container, you should now start to consume kafka messages by using the following:

bin/kafka-console-consumer.sh \
    --bootstrap-server kafka:9092 \
    --from-beginning \
    --property print.key=true \
    --topic _thetopic_

Only you have to select for yourself is the topic which consists of databasename.schema.table

Using installed kafka

You can also use your locally installed kafka to see the messages running through the broker. A preferred way, also for readability is the following:

kafka-console-consumer.sh 
    --bootstrap-server localhost:9092  
    --from-beginning 
    --property print.key=true 
    --topic <topic_name> | jq

Concrete examples

After you uploaded example_files/debezium_sonic_chracters.json, you can do this:

bin/kafka-console-consumer.sh \
    --bootstrap-server kafka:9092 \
    --from-beginning \
    --property print.key=true \
    --topic sonic.public.character

or if you use your local installed kafka

kafka-console-consumer.sh 
    --bootstrap-server localhost:9092  
    --from-beginning 
    --property print.key=true 
    --topic sonic.public.character | jq