Health Check Pattern

ELI5 — The Vibe Check

Health Checks are the 'are you alive?' ping that load balancers send to your servers. If a server stops responding, the load balancer stops sending traffic to it. It's like a teacher taking attendance — if you don't say 'here,' you don't get any work assigned to you.

Real Talk

Health check patterns involve periodic probes (HTTP, TCP, gRPC) to verify service availability and readiness. Kubernetes uses liveness probes (restart unhealthy containers), readiness probes (remove from service), and startup probes (slow-starting apps). Load balancers use health checks to route traffic only to healthy instances.

Show Me The Code

# Kubernetes health checks
livenessProbe:
  httpGet:
    path: /healthz
    port: 8080
  periodSeconds: 10
readinessProbe:
  httpGet:
    path: /ready
    port: 8080
  periodSeconds: 5

When You'll Hear This

"The readiness probe removes pods from the service during deployments." / "Our /healthz endpoint checks database connectivity, not just 'is the process alive.'"