What are readiness probes in Kubernetes and why are they important?

Readiness probes are checks that Kubernetes can use to determine if a pod is ready to receive traffic. They are important because, without proper configuration, traffic could initially be sent to pods that are not fully started, which can lead to outages.

How does graceful shutdown work in Kubernetes and why should it be implemented?

Graceful shutdown in Kubernetes ensures that old pods finish ongoing requests before they are terminated. This can be achieved by properly handling the SIGTERM signal in the application to avoid data loss and incomplete transactions.

What are the recommended maxSurge and maxUnavailable values for a zero-downtime deployment strategy?

It is recommended to set maxSurge to 25-50% to start new pods before removing old ones. maxUnavailable should be set to 0 to ensure that the desired number of pods is available at all times and to prevent outages.

How can I test if my zero-downtime deployment setup is working?

To test your setup, you should regularly check deployments under load. Tools like k6 or Locust can be used to continually send requests while the deployment is running, helping to identify issues early, such as 5xx errors.

What are pre-stop hooks and what is their purpose in Kubernetes?

Pre-stop hooks allow for a short delay before a pod is shut down. This gives the load balancer time to remove the pod from rotation, ensuring that no new requests are sent to the soon-to-be-terminated pod.

Zurück zu: Kubernetes Operations for SMEs

Kubernetes & Container 6 min. read

Zero-Downtime Deployments with Kubernetes: Configuring Rolling Updates Correctly

A misconfigured rolling update can still cause downtime even with Kubernetes. We show the most common mistakes and how to avoid them.

devRocks Engineering · 05. March 2026 · Aktualisiert: 31. March 2026 ·

Kubernetes Deployment Zero-Downtime DevOps

Zero-Downtime Deployments with Kubernetes: Configuring Rolling Updates Correctly

Why Rolling Updates Alone Are Not Enough

Kubernetes rolling updates replace pods incrementally — but without proper configuration of readiness probes, graceful shutdown, and pre-stop hooks, outages still occur.

The Three Pillars of Zero Downtime

Readiness Probes: Kubernetes needs to know when a new pod is ready to receive traffic. Without a readiness probe, traffic is sent to pods that are still starting up.
Graceful Shutdown: Old pods must complete in-flight requests before being terminated. The SIGTERM signal must be handled correctly by your application.
Pre-Stop Hooks: A short sleep (5-10 seconds) in the pre-stop hook gives the load balancer time to remove the pod from rotation before it shuts down.

Deployment Strategy

maxSurge: Set to 25-50% — allows Kubernetes to start new pods before removing old ones.
maxUnavailable: Set to 0 — ensures that the desired number of pods is always available.
minReadySeconds: Set to 10-30 seconds — prevents overly rapid rollouts in the case of creeping errors.

Test Your Setup

We recommend testing deployments regularly under load. Tools like k6 or Locust can continuously send requests during a deployment — every 5xx error reveals a gap in your zero-downtime configuration.