Manage node resources

Recommendations on managing node resources and setting eviction thresholds with Redis Enterprise for Kubernetes.

Node eviction thresholds

Kubernetes uses node-pressure eviction to terminate pods and free up node resources. Redis Enterprise for Kubernetes works best when you use the recommendations below.

Eviction thresholds are managed by kubelet arguments.

Redis recommends setting a high soft eviction threshold. This changes the node condition early enough to alert the administrator.

We also recommend setting the eviction-soft-grace-period high enough for the administrator to scale the cluster.

For more information about configuring eviction thresholds on specific platforms, see Freeing node resources for OpenShift or Cluster architecture for GKE.

Monitor node conditions

Redis recommends monitoring the node conditions. If both MemoryPressure and DiskPressure are true, the eviction threshold was met.

> kubectl get nodes -o jsonpath='{range .items[*]}name:{.metadata.name}{"\t"}MemoryPressure:{.status.conditions[?(@.type == "MemoryPressure")].status}{"\t"}DiskPressure:{.status.conditions[?(@.type == "DiskPressure")].status}{"\n"}{end}'
name:gke-55d1ac88-213c	MemoryPressure:False	DiskPressure:False
name:gke-55d1ac88-vrpp	MemoryPressure:False	DiskPressure:False
name:gke-7253cc19-42g0	MemoryPressure:False	DiskPressure:False

For more information about monitoring node conditions, see Node conditions on kubernetes.io.

Resource quotas

Kubernetes uses the ResourceQuota object to limit resource consumption per namespace. This lets you limit the number of objects created by a namespace or the amount of compute resources consumed by a namespace.

The resource settings for Redis Enterprise for Kubernetes are defined in the operator.yaml and the RedisEnterpriseCluster custom resource.

The following settings are the minimum workloads for the operator to function.

  resources:
    limits:
      cpu: 0.5
      memory: 256Mi
    requests:
      cpu: 0.5
      memory: 256Mi

For more details on using resource quotas, see the Kubernetes documentation.