第3章 Installing OpenShift Serverless

重要

You are viewing documentation for a release of Red Hat OpenShift Serverless that is no longer supported. Red Hat OpenShift Serverless is currently supported on OpenShift Container Platform 4.3 and newer.

重要

OpenShift Serverless is not tested or supported for installation in a restricted network environment.

3.1. Cluster size requirements

The cluster must be sized appropriately to ensure that OpenShift Serverless can run correctly. You can use the MachineSet API to manually scale your cluster up to the desired size.

An OpenShift cluster with 10 CPUs and 40 GB memory is the minimum requirement for getting started with your first serverless application. This usually means you must scale up one of the default MachineSets by two additional machines.

注記

For this configuration, the requirements depend on the deployed applications. By default, each pod requests ~400m of CPU and recommendations are based on this value. In the given recommendation, an application can scale up to 10 replicas. Lowering the actual CPU request of the application further pushes the boundary.

注記

The numbers given only relate to the pool of worker machines of the OpenShift cluster. Master nodes are not used for general scheduling and are omitted.

For more advanced use-cases, such as using OpenShift logging, monitoring, metering, and tracing, you must deploy more resources. Recommended requirements for such use-cases are 24 vCPUs and 96GB of memory.

Additional resources

For more information on using the MachineSet API, see Creating MachineSets.

3.1.1. Scaling a MachineSet manually

If you must add or remove an instance of a machine in a MachineSet, you can manually scale the MachineSet.

Prerequisites

  • Install an OpenShift Container Platform cluster and the oc command line.
  • Log in to oc as a user with cluster-admin permission.

Procedure

  1. View the MachineSets that are in the cluster: 

    $ oc get machinesets -n openshift-machine-api

    The MachineSets are listed in the form of <clusterid>-worker-<aws-region-az>.

  2. Scale the MachineSet: 

    $ oc scale --replicas=2 machineset <machineset> -n openshift-machine-api

    Or: 

    $ oc edit machineset <machineset> -n openshift-machine-api

    You can scale the MachineSet up or down. It takes several minutes for the new machines to be available.

    重要

    By default, the OpenShift Container Platform router pods are deployed on workers. Because the router is required to access some cluster resources, including the web console, do not scale the worker MachineSet to 0 unless you first relocate the router pods.