Overview of machine management

You can use machine management to flexibly work with underlying infrastructure such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), OpenStack, oVirt, and VMware vSphere to manage the OKD cluster. You can control the cluster and perform auto-scaling, such as scaling up and down the cluster based on specific workload policies.

It is important to have a cluster that adapts to changing workloads. The OKD cluster can horizontally scale up and down when the load increases or decreases.

Machine management is implemented as a custom resource definition (CRD). A CRD object defines a new unique object Kind in the cluster and enables the Kubernetes API server to handle the object’s entire lifecycle.

The Machine API Operator provisions the following resources:

• MachineSet

• Machine

• ClusterAutoscaler

• MachineAutoscaler

• MachineHealthCheck

Managing compute machines

As a cluster administrator, you can perform the following actions:

• Create a compute machine set for the following cloud providers:

  • AWS

  • Azure

  • GCP

  • OpenStack

  • oVirt

  • vSphere

• Manually scale a compute machine set by adding or removing a machine from the compute machine set.

• Modify a compute machine set through the MachineSet YAML configuration file.

• Delete a machine.

• Create infrastructure compute machine sets.

• Configure and deploy a machine health check to automatically fix damaged machines in a machine pool.

Managing control plane machines

As a cluster administrator, you can perform the following actions:

• Update your control plane configuration with a control plane machine set for the following cloud providers:

  • AWS

  • Azure

  • vSphere

• Configure and deploy a machine health check to automatically recover unhealthy control plane machines.

Applying autoscaling to an OKD cluster

You can automatically scale your OKD cluster to ensure flexibility for changing workloads. To autoscale your cluster, you must first deploy a cluster autoscaler, and then deploy a machine autoscaler for each compute machine set.

• The cluster autoscaler increases and decreases the size of the cluster based on deployment needs.

• The machine autoscaler adjusts the number of machines in the compute machine sets that you deploy in your OKD cluster.

Adding compute machines on user-provisioned infrastructure

User-provisioned infrastructure is an environment where you can deploy infrastructure such as compute, network, and storage resources that host the OKD. You can add compute machines to a cluster on user-provisioned infrastructure during or after the installation process.

Adding RHEL compute machines to your cluster

As a cluster administrator, you can perform the following actions:

• Add Red Hat Enterprise Linux (RHEL) compute machines, also known as worker machines, to a user-provisioned infrastructure cluster or an installation-provisioned infrastructure cluster.

• Add more Red Hat Enterprise Linux (RHEL) compute machines to an existing cluster.