Kafka demo

sboot/kotlin reusable building blocks for kafka event-driven pipelines

• clustering / replication / partitioning
• Avro schema / registry
• transactional outbox publish
• idempotent transactional inbox consume
• manual CDC
• automatic CDC / outbox publish with Debezium
• backoff / retry / rescue
• dead lettering
• GraalVM
• mTLS / ACLs

overview

env

can be modified using compose.yaml and .env

components

kafka-demo/ # parent pom
├── commons/ # shared libs/abstractions, Avro schemas/codegen, test fixtures
├── order-api/
├── inventory-service/

order-api

inventory-service

run

docker compose pull && docker compose up

order-api | kafbat UI | jaeger | grafana

test

curl -iLX 'POST' \
  'http://localhost:8080/api/order' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{"customerId":"user_2203","items":[{"sku":"sku-01","quantity":10,"unitPriceCents":199}]}'

load test

oha

oha -n 5000 -c 500 --redirect 0 \
  -m POST \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{"customerId":"user_2203","items":[{"sku":"sku-01","quantity":10,"unitPriceCents":199}]}' \
  http://localhost:8080/api/order

# -n total request
# -c concurrent connection

expect n to land in orders.placed and around 50% of n to land in orders.[accepted|rejected] each

chaos test

pause or stop any Kafka container mid-load test, order-api | inventory-service | debezium/connect should recover automatically after 1st timeout

build

sdkman | nvm

nvm use && npm i && sdk env install

JVM

./gradlew clean ktlintFormat ktlintCheck build jibDockerBuild -x processAot -x processTestAot
docker compose -f compose.jvm.yaml up

GraalVM

./gradlew clean ktlintFormat ktlintCheck build -PgenerateMetadata
./gradlew buildImage
docker compose up