Scaling Up for Production
Moving workloads from a local development environment to a production Kubernetes cluster requires a major shift in configuration. Out-of-the-box defaults are rarely sufficient for high-availability systems. Production readiness is about ensuring resilience, resource boundaries, and secure environments.
1. Define Resource Requests and Limits
If you don’t define resource requests and limits for your containers, a single runaway process can consume all CPU and memory on a node, causing neighboring pods to crash. This is known as the “noisy neighbor” problem.
# Recommended resource configuration pattern
resources:
requests:
memory: "256Mi"
cpu: "250m"
limits:
memory: "512Mi"
cpu: "500m"Always set requests to what the pod needs under normal load, and limits to the absolute maximum it should be allowed to consume before being throttled (CPU) or terminated (Memory).
2. Configure Liveness and Readiness Probes
Probes tell Kubernetes if a pod is healthy and ready to receive traffic. Without them, the ingress might route users to a pod that is still initializing or in a locked state.
- Readiness Probe: Checks if the container is ready to accept traffic. If it fails, the pod is removed from service endpoints.
- Liveness Probe: Checks if the container needs to be restarted. If it fails, Kubernetes kills the pod and starts a new one.
3. Implement Network Policies
By default, all pods in a Kubernetes cluster can communicate with all other pods. For production security, you must restrict this. Databases should only accept connections from application pods, and external traffic should only hit public load balancers.