kafka-spring-cloud-stream

Spring Cloud Stream Showcase with Apache Kafka

Produce Data

Add products to topic product-in-topic, e.g.:

{"id": "001", "name": "IPad", "description": "The new 2021 IPad Pro"}
{"id": "002", "name": "Nokia X20", "description": "Middleclass Nokia Phone"}

Consume Data

Get products with:

http://localhost:8080/product/[id]

Interactive Query Service

When scaling the application, the state is distributed among the state stores of the different instances. The interactive query service can detect the instance that is holding the requested key and can query it over RPC Mechanisms. See documentation on Confluent and Spring Cloud Stream .

To test this behaviour:

1. Create the topic product-in-topic with multiple partitions (e.g. 3)
2. Create multiple instances of the application by overwriting the server.port property (e.g. 8080, 8081, 8082)
3. Produce some data to the topic
4. Query a product from different instances. The log now states Loading local product or Loading remote product, depending on the source

Get Topology

The Topology can be shown using the following endpoint:

http://localhost:8080/actuator/kafkastreamstopology/showcase