This is a simple service that provides a RESTful API for managing student grades in a school. The service is built using Python and FastAPI, and it uses a PostgreSQL database to store student, subject, and grade information.
- Python 3.10
- Docker
- Docker Compose
- Clone the repository:
git clone git@github.com:ariel1985/linear_scale_grade_sys.git- Change into the project directory:
cd linear-scale-grade-service- Create a
.envfile in the project root directory with the following environment variables:
DATABASE_URL=postgresql://postgres:postgres@db/postgres- Build and start the Docker containers:
docker-compose up --build
# or use the load balancer acting as linear scale
docker-compose up --scale api=3Note: To sync between the database and API service, the loading time takes about 10 seconds.
- The service should now be running at
http://localhost:8000.
To view the API documentation, navigate to http://localhost:8000/docs.
Load Balancer Acting as Linear Scale The Nginx load balancer allows horizontal scaling by distributing incoming HTTP requests across multiple instances of the FastAPI application. Here’s how it works:
Upstream Servers:
The upstream block in the nginx.conf file defines a group of servers (api_servers). Requests to the load balancer are distributed among these servers. Currently, it points to a single instance (api:8000). For true horizontal scaling, you can deploy multiple instances of the FastAPI application. Load Balancing:
Nginx balances the incoming traffic across the defined upstream servers. This means if you scale the api service to multiple replicas, Nginx will distribute the traffic among them.
docker-compose up --scale api=3