What Is a Rolling Update?

Rolling Update is a deployment strategy that gradually replaces old instances of an application with new ones, one or a few at a time, rather than updating all simultaneously. During the update, both old and new versions run concurrently, ensuring the service remains available throughout. Rolling updates are the default deployment strategy in Kubernetes Deployments and the most commonly used approach for production releases.

Why Rolling Updates Matter

Updating all application instances at once causes downtime because there is a period where no instances are available. Rolling updates avoid this by ensuring a minimum number of healthy instances are always running. If the new version has issues, the update can be paused or rolled back before all instances are affected, making it a safe default for most production deployments.

Teams that understand and adopt rolling update gain a significant operational advantage, reducing manual effort and improving the reliability and scalability of their infrastructure. As cloud-native adoption accelerates, familiarity with rolling update has become a core competency for DevOps engineers, platform teams, and site reliability engineers working in production Kubernetes and cloud environments.

How Rolling Updates Work

The update process creates new pods running the updated version while keeping old pods running. As each new pod passes health checks and becomes ready, an old pod is terminated. This continues until all pods run the new version. You can configure the maximum unavailable pods and maximum surge of extra pods using maxUnavailable and maxSurge parameters in the Deployment spec for fine-grained control over the rollout pace.

Understanding how rolling update fits into the broader cloud-native ecosystem is important for making informed architecture decisions. It works alongside other tools and practices in the DevOps and platform engineering space, and choosing the right combination depends on your team's specific requirements, scale, and operational maturity.

Key Features

Zero Downtime

By maintaining a minimum number of available instances, rolling updates keep the service accessible throughout deployment.

Configurable Pace

Control how many pods are updated simultaneously using maxUnavailable and maxSurge parameters.

Health Check Integration

New pods must pass readiness probes before old pods are terminated, preventing traffic to unhealthy instances.

Automatic Rollback

If new pods fail health checks, the update halts and can be rolled back to the previous working version.

Common Use Cases

Deploying application updates to production without any service interruption for end users.

Updating microservices that need to maintain continuous availability during every deployment.

Rolling out security patches across a fleet of pods while keeping the service fully operational.

Upgrading container images to new versions as the default deployment strategy in Kubernetes.

How Obsium Helps

Obsium's DevOps solutions team helps organizations implement and optimize rolling update as part of production-grade infrastructure. Whether you are adopting rolling update for the first time or looking to improve an existing implementation, our engineers bring hands-on experience across cloud platforms and Kubernetes environments. Learn more about our DevOps solutions services →