Types of Probes in EKS (Kubernetes)

✅ Types of Probes in EKS (Kubernetes)

🔹 1. Liveness Probe

Purpose: Checks if the container is still alive.

Action: If it fails, Kubernetes kills the container and restarts it.

Use case: Useful when your app hangs or enters a deadlock.

livenessProbe:
  httpGet:
    path: /healthz
    port: 8080
  initialDelaySeconds: 10
  periodSeconds: 15

Example: A Spring Boot app hangs due to a memory leak — the liveness probe fails, and the pod restarts automatically.

🔹 2. Readiness Probe

Purpose: Checks if the container is ready to receive traffic.

Action: If it fails, the pod is removed from Service load balancing.

Use case: Ensures traffic is only routed to healthy and initialized containers.

readinessProbe:
  httpGet:
    path: /readiness
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 10

Example: A microservice needs time to warm up and connect to a DB — readiness ensures no traffic hits it before it's ready.

🔹 3. Startup Probe

Purpose: Checks if the container has started successfully.

Action: Gives the container more time to start before liveness checks begin.

Use case: Ideal for slow-starting applications.

startupProbe:
  httpGet:
    path: /startup
    port: 8080
  failureThreshold: 30
  periodSeconds: 10

Example: A legacy Java app takes 3 minutes to start — startup probe delays liveness checks to avoid premature kills.