Managing and maintaining containerized applications' health and life-cycle using Kubernetes

In Kubernetes for managing and maintaining containerized applications' health and lifecycle probes are essential tool specially in production environments. They are used to monitor the state of your application and ensure it behaves as expected within a cluster. Here’s how probes contribute to Kubernetes container management

Types of Probes and Their Role

Readiness Probe

Determines if a container is ready to serve traffic.

Used for traffic routing.

Ensures that only healthy containers receive traffic from Kubernetes services.

Scenario: If an application requires some warm-up time (e.g., loading large datasets), the readiness probe prevents traffic until the container is fully ready.

Liveness Probe

Ensures the container is running properly.

Restarts containers that are stuck or in a deadlocked state.

Scenario: If an application process hangs due to a deadlock or memory issue, the liveness probe triggers a container restart.

Startup Probe

Ensures that a container has started successfully before other probes are activated.

Prevents false failures from liveness or readiness probes during slow application startups.

Scenario: A Java application might take a few minutes to initialize. The startup probe allows it to complete initialization without being prematurely restarted by the liveness probe.