Scalability is the ability to accommodate increasing workload or resource demands while keeping operation acceptable. In deployment work, it means running multiple application instances and distributing traffic among them instead of relying on one container. section 7.4.1 section 8.3.3
A practical scaling path moves from manual duplication toward declarative management:
- Docker Compose can run several services from the same application container image. section 7.4.1
- NGINX can define those services as an upstream and load-balance requests across them. section 7.4.1
- Kubernetes Deployments declare a desired replica count, and Services load-balance traffic to available, ready Pods. section 8.3.3
Scaling an NGINX application
A Kubernetes Deployment can declare replicas: 15 for an NGINX container. Applying the manifest with kubectl apply -f my-first-deployment.yaml creates the desired group of Pods; kubectl get deployments and kubectl get pods --selector app=my-nginx verify the result. section 8.3.3
