Request Flow Overview
This diagram illustrates the complete flow of a request through a Kubernetes cluster, from the external client to the application pod and back. Understanding this flow is crucial for system design interviews and troubleshooting Kubernetes applications.
The flow typically involves multiple components working together: external load balancer, ingress controller, service, and pods. Each component has a specific role in routing, load balancing, and managing the request lifecycle.
External Load Balancer
Distributes incoming traffic across multiple ingress controllers for high availability and load distribution.
Ingress Controller
Manages external access to services, handles SSL termination, and provides HTTP/HTTPS routing rules.
Service
Provides stable network identity and load balancing for a set of pods, abstracting pod IPs.
Pod
Contains the actual application containers and handles the business logic of the request.
Interview Questions
System Design Questions
- How would you design a highly available Kubernetes cluster?
- What happens if the ingress controller fails?
- How would you implement canary deployments in this flow?
- Explain the role of service mesh in this architecture.
Technical Deep Dives
- How does kube-proxy implement load balancing?
- What's the difference between a Service and an Ingress?
- Explain the role of etcd in this flow.
- How does service discovery work in Kubernetes?
Troubleshooting Scenarios
- A user reports the application is slow, how do you debug?
- Requests are failing, where would you look first?
- How do you monitor a Kubernetes application?
- What happens when a pod becomes unhealthy?