ResourceQuotas

ResourceQuotas, also known as ResourceQuota objects, are namespace-scoped API resources in Kubernetes that limit the total amount of resources and the number of objects that can be created within a namespace. They help prevent resource exhaustion, enable fair sharing among teams, and provide predictable resource availability.

A quota defines hard limits in spec.hard. Each entry maps a resource name to a quantity. Common keys include pods, services, persistentvolumeclaims, and secrets, as well as numeric resources such as requests.cpu, limits.cpu, requests.memory, limits.memory, and requests.storage. The quota tracks the resource requests of objects (and, for some resources, actual usage) and denies requests that would exceed the configured limits.

Enforcement happens at admission time. When a pod, service, or other object is created or updated, the API server checks the resulting usage against spec.hard. If the new usage would exceed the quota, the operation is rejected with an error. Quotas are namespace-scoped and do not automatically apply across the entire cluster.

Status and management. The status field records how much of each resource has been used in the namespace. Administrators can monitor quota usage and adjust quotas as needs change. Quotas work alongside LimitRange, which can enforce per-container resource limits and defaults.

Notes. Quotas are not retroactive to existing resources beyond the namespace as of their creation; reducing quotas may require deleting or resizing existing objects. They are a key tool for multi-tenant cluster management in Kubernetes.