Scaling Dockerized Back Ends

1. Introduction

Scaling Dockerized back ends efficiently is crucial for modern applications. This lesson covers essential concepts, methods, and best practices for scaling services packaged in Docker containers.

2. Key Concepts

3. Scaling Methods

Scaling can be achieved through various methods:

• Horizontal Scaling: Adding more instances of containers.
• Vertical Scaling: Increasing resources (CPU, RAM) of existing containers.
• Auto-Scaling: Automatically adjusting the number of running containers based on load.

3.1 Horizontal Scaling Example

docker run -d --name myapp-1 myapp:latest
docker run -d --name myapp-2 myapp:latest

4. Load Balancing

Load balancing distributes incoming traffic across multiple container instances:

• Use a reverse proxy like NGINX or HAProxy.
• Configure your load balancer to route traffic evenly.
• Monitor performance and adjust configurations as needed.

4.1 Example NGINX Configuration

http {
    upstream myapp {
        server myapp-1:80;
        server myapp-2:80;
    }

    server {
        location / {
            proxy_pass http://myapp;
        }
    }
}

5. Best Practices

• Use environment variables for configuration.
• Keep images small to reduce deployment time.
• Regularly update dependencies and images.

6. FAQ