In this tutorial, we will re-implement the stream-query with ksqldb instead of Kafka Streams. Codegen The README.md and config.json to scaffold a project in the light-example-4j can be found at the following URL. https://github.com/networknt/model-config/tree/master/kafka/ksqldb-query The generated project can be found at https://github.com/networknt/light-example-4j/tree/master/kafka/ksqldb-query Start Confluent Download and install the confluent 6.0.1 locally with tar.gz file and start the services confluent local services start The ksqlDB server will be started along with other services. Read More »

In the previous stream-query tutorial, we have demonstrated how to build a Kafka Streams service with light-rest-4j. This tutorial will create another microservice with Kafka Streams to consume the same topic with the event sourcing. In the real business environment, this service might be created several years later when the CEO asks how many registered users per country per year since the beginning. The project is the report service that has /report get endpoint. Read More »

In the previous producer-consumer tutorial, we have demonstrated how to build a producer and consumer with light-rest-4j. In this tutorial, we will create a microservice with Kafka Streams to simulate the event sourcing. The previously built producer will be reused to simulate the command side for the CQRS. The project is the query service that has /query and /query/{userId} get endpoints. Codegen As usual, you can find the specification, config.json and a README. Read More »

This tutorial will build a microservice that produces a list of users to a Kafka topic and consumes the list of users with another get endpoint. Codegen To scaffold a new project, we put the README.md, openapi.yaml and config.json to the model-config repo in the following folder. https://github.com/networknt/model-config/tree/master/kafka/producer-consumer The command line is in the README.md, and the specification has two endpoints. The generated project is located in the light-example-4j. https://github.com/networknt/light-example-4j/tree/master/kafka/producer-consumer Read More »