Active/Passive Kubernetes deployment for high availability stateful applications

Welcome to my blog where we will be discussing the active/passive Kubernetes deployment for high availability stateful applications. Kubernetes has become the go-to platform for deploying and managing containerized applications. With its ability to provide high availability, scalability, and resiliency, it is no surprise that Kubernetes is widely used for stateful applications that require persistent storage. In this blog, we will explore the active/passive Kubernetes deployment model and how it can be used to ensure high availability for stateful applications.

Active/Passive Deployment Model

The active/passive deployment model is a common approach used to ensure high availability for stateful applications. In this deployment model, there are two identical sets of infrastructure, one active and the other passive. The active set handles all the traffic and workload, while the passive set is on standby, ready to take over in case the active set fails. The passive set is configured to mirror the active set, including network configurations, storage configurations, and application configurations. This ensures that the passive set can take over seamlessly and provide continuity of service without any downtime.

Active/Passive Deployment for Kubernetes

Kubernetes provides several ways to achieve high availability for stateful applications. One such method is the active/passive deployment model. In Kubernetes, an active/passive deployment is achieved by using StatefulSets and a load balancer. StatefulSets are used to manage the stateful application, and the load balancer is used to distribute traffic between the active and passive sets.

To set up an active/passive deployment in Kubernetes, follow these steps:

Step 1: Set up the Active Set

Create a StatefulSet that defines the active set. This StatefulSet should include the desired number of replicas for the application, storage configurations, network configurations, and other application-specific configurations.

Step 2: Set up the Passive Set

Create a second StatefulSet that defines the passive set. This StatefulSet should be identical to the active set, including storage configurations, network configurations, and application-specific configurations. However, it should have zero replicas to ensure that it is not running any workload.

Step 3: Set up the Load Balancer

Set up a load balancer to distribute traffic between the active and passive sets. This can be achieved using a Kubernetes Service object with a LoadBalancer type.

Step 4: Monitoring and Failover

Set up monitoring for the active set. This can be done using Kubernetes health checks or external monitoring tools. If the active set fails, the load balancer should automatically redirect traffic to the passive set. The passive set should be configured to take over seamlessly without any downtime.

Conclusion

In conclusion, the active/passive deployment model is an effective way to ensure high availability for stateful applications in Kubernetes. It provides redundancy and failover capabilities, ensuring continuity of service in case of a failure. By following the steps outlined in this blog, you can set up an active/passive deployment for your stateful application in Kubernetes.