OpenShift Resource Management Concepts

External

• https://docs.openshift.com/container-platform/latest/dev_guide/compute_resources.html#dev-guide-compute-resources
• https://docs.openshift.com/container-platform/latest/admin_guide/quota.html

Internal

• OpenShift Concepts

Overview

OpenShift provides API-level support for establishing and enforcing resource quotas. The runtime monitors resource usage and intervenes when the quotas are reached or exceeded. Resource quotas can be set up and managed on the following type of resources: the quantity of objects that can be created per project, the amount of compute resources (requests and limits on CPU and memory) consumed by the project and individually by project entities such as pods and containers, the amount of storage consumed by project entities. Opaque integer resources can also be set and monitored.

Resource monitoring and consumption is important because it insures that no projects are using more resources that is appropriate for the cluster size. Primarily, resource constraints are set by the cluster administrators, but developers can also set request and limits on compute resources.

Quota

A resource quota specifies constraints that limit aggregate resource consumption per project, and they are set by cluster administrators. The resource quota is defined by a ResourceQuota object. The resource quota limits:

• the quantity of objects, per type, that can be created in a project.
• the total amount of compute resources consumed by the project.
• the total amount of storage consumed by the project.

Organizatorium

ResourceQuota object enumerates hard resource usage limits per project.

ClusterResourceQuota object enumerates hard resource usage limits across the cluster.

Resource Quota Definition

Operations:

• oc get quota
• oc describe quota
• oc create

Enforcement

With cgroups?

Limits

Memory Limit

Propagates as /sys/fs/cgroup/memory/memory.limit_in_bytes in container.