1.4. Preparing your hub cluster for installation

Before you install Red Hat Advanced Cluster Management for Kubernetes, review the following installation requirements and recommendations for setting up your hub cluster:

1.4.1. Confirm your Red Hat OpenShift Container Platform installation

  • You must have a supported Red Hat OpenShift Container Platform version, including the registry and storage services, installed and working in your cluster. For more information about installing the Red Hat OpenShift Container Platform, see the Red Hat OpenShift documentation.
  • For Red Hat OpenShift Container Platform version 4.3, see Red Hat OpenShift Container Platform 4.3 Documentation.

  • To ensure that the Red Hat OpenShift Container Platform cluster is set up correctly, access the Red Hat OpenShift Container Platform web console.

    Run the kubectl -n openshift-console get route command to access the Red Hat OpenShift Container Platform web console. See the following example output: 

      openshift-console          console             console-openshift-console.apps.new-coral.purple-chesterfield.com                       console                  https   reencrypt/Redirect     None

    The console URL in this example is https:// console-openshift-console.apps.new-coral.purple-chesterfield.com. Open the URL in your browser and check the result. If the console URL displays console-openshift-console.router.default.svc.cluster.local, set openshift_master_default_subdomain when you install the Red Hat OpenShift Container Platform.

See Sizing your cluster to learn about setting up capacity for your hub cluster.

1.4.2. Sizing your cluster

Each Red Hat Advanced Cluster Management for Kubernetes cluster has its own characteristics. There are guidelines that provide sample deployment sizes. They have been classified by size and purpose. The considerations are focused on clusters that are either deployed to VMware or OpenStack environments.

Red Hat Advanced Cluster Management applies the following 3 dimensions for sizing and placement of supporting services:

  • Availability Zones that isolate potential fault domains across the cluster. Typical clusters should have roughly equivalent worker node capacity in 3 or more availability zones.
  • vCPU reservations and limits establish vCPU capacity on a worker node to assign to a container. A vCPU is equivalent to a Kubernetes compute unit. For more information, see Kubernetes Meaning of CPU.
  • Memory reservations and limits establish memory capacity on a worker node to assign to a container. Reservations establish a lower bound of CPU or memory and limits establish an upper bound.

The persistent data managed by the product is stored in the cluster-wide etcd data store. Best practices for OpenShift recommend distributing the master nodes of the cluster across three (3) availability zones, as well.

Note: The requirements that are listed are not minimum requirements.

1.4.2.1. Red Hat Advanced Cluster Management for Kubernetes environment

表 1.1. Table of the product environment

OpenShift node roleAvailability zonesData storesTotal reserved memory (lower bound)Total reserved CPU (lower bound)

master

3

etcd x 3

Per OpenShift sizing guidelines

Per OpenShift sizing guidelines

worker

3

redisgraph or redis x 1

12 Gi

6 CPU

In addition to Red Hat Advanced Cluster Management for Kubernetes, the OpenShift cluster runs additional services to support cluster features. The following list contains the recommended sizes of the three (3) installed nodes that are distributed across availability zones for each of the providers.

  • Creating an OpenShift cluster on Amazon Web Services

    See the Amazon Web Services information in the Red Hat OpenShift product documentation for more information. Also learn more about machine types.

    • Node Count: 3
    • Availability zones: 3

    • Instance size: m5.xlarge

      • vCPU: 4
      • Memory: 16 GB
      • Storage size: 120 GB

  • Creating an OpenShift cluster on Google Cloud Platform

    See the Google Cloud Platform product documentation for more information about quotas. Also learn more about machine types.

    • Node Count: 3
    • Availability zones: 3

    • Instance size: N1-standard-4 (0.95—​6.5 GB)

      • vCPU: 6
      • Memory: 15 GB
      • Storage size: 120 GB

  • Creating an OpenShift cluster on Microsoft Azure See the following product documentation for more details.

    • Node Count: 3
    • Availability zones: 3

    • Instance size: Standard_D2s_v3

      • vCPU: 6
      • Memory: 16 GB
      • Storage size: 120 GB

  • Creating an OpenShift cluster on bare metal See the following product documentation for more details.

    • CPU: 6 (minimum)
    • Memory: 16 GB (minimum)
    • Storage size: 50 GB (minimum)