Upgrade Redis Enterprise for Kubernetes
Redis implements rolling updates for software upgrades in Kubernetes deployments. The upgrade process includes updating three components:
- Upgrade the Redis Enterprise operator
- Upgrade the Redis Enterprise cluster (REC)
- Upgrade Redis Enterprise databases (REDB)
To use OpenShift container platform CLI to upgrade your Redis Enterprise, see Upgrade Redis Enterprise with OpenShift CLI.
For all other Kubernetes distributions, see Upgrade Redis Enterprise for Kubernetes.
How does the REC upgrade work?
The Redis Enterprise cluster (REC) uses a rolling upgrade, meaning it upgrades pods one by one. Each pod is updated after the last one completes successfully. This helps keep your cluster available for use.
To upgrade, the cluster terminates each pod and deploys a new pod based on the new image. Before each pod goes down, the operator checks if the pod is a primary (master) for the cluster, and if it hosts any primary (master) shards. If so, a replica on a different pod is promoted to primary. Then when the pod is terminated, the API remains available through the newly promoted primary pod.
After a pod is updated, the next pod is terminated and updated. After all of the pods are updated, the upgrade process is complete.