kafka-outbox-pattern

Implementation of the outbox pattern using Spring Cloud Stream Kafka

Running the app:

Download the Confluent Platform:

git clone https://github.com/confluentinc/cp-docker-images

Configure transactional support in development mode (1 broker) in examples/cp-all-in-one/docker-compose.yml:

• Necessary for transactional producers:

KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1

• Necessary for exactly_once KStreams:

KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1

Start the Confluent Platform:

cd cp-docker-images
git checkout 5.2.2-post
cd examples/cp-all-in-one/
docker-compose up -d --build

Go to the root of the sample project and do:

./gradlew clean build -b ./account-service/build.gradle.kts

./gradlew clean build -b ./message-relay-service/build.gradle.kts

./gradlew clean build -b ./transfer-service/build.gradle.kts

java -jar account-service/build/libs/account-service-1.0.0-SNAPSHOT.jar

java -jar account-service/build/libs/message-relay-service-1.0.0-SNAPSHOT.jar

java -jar transfer-service/build/libs/transfer-service-1.0.0-SNAPSHOT.jar

Create two accounts:

curl -X POST http://localhost:8080/accounts -H "content-type: application/json" -d '{"ownerId": "1234D", "ownerName": "John Doe", "funds": 2000.00}'

curl -X POST http://localhost:8080/accounts -H "content-type: application/json" -d '{"ownerId": "2225X", "ownerName": "Anne Mary", "funds": 2000.00}'

Create some transfers between the existing accounts:

curl -X PUT http://localhost:8080/accounts/transfers -H "content-type: application/json" -d '{"sourceAccountId": 1, "destinationAccountId": 2, "ammount": 100.00}'

Observe the state of:

• The account database table (account-service): http://localhost:8080/accounts

• The outbox database table (message-relay-service): http://localhost:8085/outbox

• The transfer database table (transfer-service): http://localhost:8084/transfers