CQRS demo project

It's a simple demo project contains 2 services:

• master: source of domain models. Stores models in PostgreSQL.
• replica: service which get models from master by CQRS. Stores replicated models in MySQL and Redis

Start project:

docker compose up -d db_pgsql db_mysql
docker compose run master ./manage.py migrate
docker compose run replica ./manage.py migrate
docker compose up -d
docker compose run master ./manage.py cqrs_sync --cqrs-id=user -f={}
docker compose run master ./manage.py cqrs_sync --cqrs-id=product -f={}

It starts master WEB app on http://127.0.0.1:8000 and replica on http://127.0.0.1:8001

You can do something with model instances via WEB interface or django shell on master and see how data changes in replica too.

Domain models:

User:

The most common and simple way for replication is used for this model.

ProductType:

This model isn't being synchronized separately, only with related Product.

Product:

This models uses custom own written serializer and relation optimization.

Purchase:

This models uses Django REST Framework serializer. Replica service stores this model in redis.

Monitoring

You can monitor CQRS queue by tools provided by chosen transport backend.

For this demo we use RabbitMQ with management plugin. You can find it on http://127.0.0.1:15672 with credentials rabbitmq / password.