Project 05

Spring Boot Postgres - CQRS (Multiple Database)

https://gitorko.github.io/post/distributed-locking-postgres

Version

Check version

$java --version
openjdk 21.0.3 2024-04-16 LTS

Postgres DB

Start 2 Database Servers

docker-compose -f docker/docker-compose.yaml up -d

Enable replication after liquibase creates the tables, run this only after spring boot application is started.

docker-compose -f docker/enable-publication.yaml up -d
docker-compose -f docker/enable-subscription.yaml up -d

Command to verify replication

docker exec -it pg-source psql -U test -d source_db -c "SELECT * FROM pg_roles WHERE rolname = 'replicator';"
docker exec -it pg-source psql -U test -d source_db -c "SELECT * FROM pg_publication;"
docker exec -it pg-target psql -U test -d target_db -c "SELECT * FROM pg_subscription;"

docker exec -it pg-source psql -U test -d source_db -c "SELECT * FROM pg_replication_slots;"
docker exec -it pg-target psql -U test -d target_db -c "SELECT * FROM pg_stat_subscription;"

docker exec -it pg-source psql -U test -d source_db -c "SELECT * FROM pg_create_logical_replication_slot('employee_slot', 'pgoutput');"

Clean up

docker-compose -f docker/docker-compose.yaml down --rmi all --remove-orphans --volumes

Dev

To run the backend in dev mode.

./gradlew clean build
./gradlew bootRun