Tips for using Managed Service for Kubernetes

Use these recommendations for your PRODUCTION applications that require:

• High availability and fault tolerance.
• Load scaling.
• Resource isolation.

High availability and fault toleranceHigh availability and fault tolerance

• Use the REGULAR or STABLE release channel. NodeLocal DNS and Pod Topology Constraints are available in all Kubernetes versions.

• Update your cluster and your node groups manually. To do this, disable automatic master and node group updates.

• Select the highly available master type located in three zones. Kubernetes services will be available in the event of an availability zone level failure. The Managed Service for Kubernetes [Service Level Agreement] applies to the configuration with a highly available master located in three zones.

• Deploy your Deployment and StatefulSet type services in multiple instances in different availability zones. Use the Pod Topology Constraints and the AntiAffinity strategies to ensure high service availability and efficient usage of Kubernetes cluster resources.

  Use the label combinations below for all strategies:

  • topology.kubernetes.io/zone to keep the services available in the event of an availability zone failure.
  • kubernetes.io/hostname to keep the services available in the event of a cluster node failure.

  Tip

  Test the strategies in a test environment before migrating them to PRODUCTION.

Load scalingLoad scaling

Use these recommendations if the load on your Managed Service for Kubernetes cluster is constantly growing:

• To make your cluster more robust, create node groups with automatic scaling in multiple availability zones.
• To reduce the load on the Kubernetes DNS, use NodeLocal DNS. If the cluster contains over 50 nodes, use automatic DNS scaling.
• To reduce horizontal traffic within the cluster, use a Network Load Balancer and the externalTrafficPolicy:Local rule where possible.
• Consider node storage requirements in advance:
  • Review disk limits for Yandex Compute Cloud.
  • Load test your disk subsystem in a test environment.
• To reduce latency at high IOPS, use non-replicated disks.

Isolating resourcesIsolating resources

Follow these recommendations for applications that use shared Kubernetes cluster resources.

Adjust limits and requests for all the cluster services:

---
...
containers:
...
  resources:
    limits:
      cpu: 250m
      memory: 128Mi
    requests:
      cpu: 100m
      memory: 64Mi
...

Specify vCPU availability in thousandths and RAM in megabytes. The service will not exceed the vCPU or RAM limits specified in limits. Customized requests allow you to autoscale cluster nodes.

To manage pod resources automatically, configure Kubernetes policies:

• Quality of Service for Pods to create pods of different availability classes.
• Limit Ranges to set limits at the namespace level.