# Configure Quality of Service for Pods
LLMS index: [llms.txt](/llms.txt)
---
This page shows how to configure Pods so that they will be assigned particular
Quality of Service (QoS) classes.
Kubernetes uses QoS classes to make decisions about evicting Pods when Node resources are exceeded.
When Kubernetes creates a Pod it assigns one of these QoS classes to the Pod:
* [Guaranteed](/docs/concepts/workloads/pods/pod-qos/#guaranteed)
* [Burstable](/docs/concepts/workloads/pods/pod-qos/#burstable)
* [BestEffort](/docs/concepts/workloads/pods/pod-qos/#besteffort)
Note:
Kubernetes assigns the QoS class when the Pod is created, and it remains unchanged
for the lifetime of the Pod. If you attempt to
resize the Pod's resources
to values that would result in a different QoS class, control plane rejects your request with an error message.
You need to have a Kubernetes cluster, and the kubectl command-line tool must
be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a
cluster, you can create one by using
minikube
or you can use one of these Kubernetes playgrounds:
You also need to be able to create and delete namespaces.
## Create a namespace
Create a namespace so that the resources you create in this exercise are
isolated from the rest of your cluster.
```shell
kubectl create namespace qos-example
```
## Create a Pod that gets assigned a QoS class of Guaranteed
For a Pod to be given a QoS class of `Guaranteed`:
* Every Container in the Pod must have a memory limit and a memory request.
* For every Container in the Pod, the memory limit must equal the memory request.
* Every Container in the Pod must have a CPU limit and a CPU request.
* For every Container in the Pod, the CPU limit must equal the CPU request.
These restrictions apply to init containers and app containers equally.
[Ephemeral containers](/docs/concepts/workloads/pods/ephemeral-containers/)
cannot define resources so these restrictions do not apply.
Here is a manifest for a Pod that has one Container. The Container has a memory limit and a
memory request, both equal to 200 MiB. The Container has a CPU limit and a CPU request, both equal to 700 milliCPU:
apiVersion: v1
kind: Pod
metadata:
name: qos-demo
namespace: qos-example
spec:
containers:
- name: qos-demo-ctr
image: nginx
resources:
limits:
memory: "200Mi"
cpu: "700m"
requests:
memory: "200Mi"
cpu: "700m"
Create the Pod:
```shell
kubectl apply -f https://k8s.io/examples/pods/qos/qos-pod.yaml --namespace=qos-example
```
View detailed information about the Pod:
```shell
kubectl get pod qos-demo --namespace=qos-example --output=yaml
```
The output shows that Kubernetes gave the Pod a QoS class of `Guaranteed`. The output also
verifies that the Pod Container has a memory request that matches its memory limit, and it has
a CPU request that matches its CPU limit.
```yaml
spec:
containers:
...
resources:
limits:
cpu: 700m
memory: 200Mi
requests:
cpu: 700m
memory: 200Mi
...
status:
qosClass: Guaranteed
```
Note:
If a Container specifies its own memory limit, but does not specify a memory request, Kubernetes
automatically assigns a memory request that matches the limit. Similarly, if a Container specifies its own
CPU limit, but does not specify a CPU request, Kubernetes automatically assigns a CPU request that matches
the limit.
#### Clean up {#clean-up-guaranteed}
Delete your Pod:
```shell
kubectl delete pod qos-demo --namespace=qos-example
```
## Create a Pod that gets assigned a QoS class of Burstable
A Pod is given a QoS class of `Burstable` if:
* The Pod does not meet the criteria for QoS class `Guaranteed`.
* At least one Container in the Pod has a memory or CPU request or limit.
Here is a manifest for a Pod that has one Container. The Container has a memory limit of 200 MiB
and a memory request of 100 MiB.
apiVersion: v1
kind: Pod
metadata:
name: qos-demo-2
namespace: qos-example
spec:
containers:
- name: qos-demo-2-ctr
image: nginx
resources:
limits:
memory: "200Mi"
requests:
memory: "100Mi"
Create the Pod:
```shell
kubectl apply -f https://k8s.io/examples/pods/qos/qos-pod-2.yaml --namespace=qos-example
```
View detailed information about the Pod:
```shell
kubectl get pod qos-demo-2 --namespace=qos-example --output=yaml
```
The output shows that Kubernetes gave the Pod a QoS class of `Burstable`:
```yaml
spec:
containers:
- image: nginx
imagePullPolicy: Always
name: qos-demo-2-ctr
resources:
limits:
memory: 200Mi
requests:
memory: 100Mi
...
status:
qosClass: Burstable
```
#### Clean up {#clean-up-burstable}
Delete your Pod:
```shell
kubectl delete pod qos-demo-2 --namespace=qos-example
```
## Create a Pod that gets assigned a QoS class of BestEffort
For a Pod to be given a QoS class of `BestEffort`, the Containers in the Pod must not
have any memory or CPU limits or requests.
Here is a manifest for a Pod that has one Container. The Container has no memory or CPU
limits or requests:
apiVersion: v1
kind: Pod
metadata:
name: qos-demo-3
namespace: qos-example
spec:
containers:
- name: qos-demo-3-ctr
image: nginx
Create the Pod:
```shell
kubectl apply -f https://k8s.io/examples/pods/qos/qos-pod-3.yaml --namespace=qos-example
```
View detailed information about the Pod:
```shell
kubectl get pod qos-demo-3 --namespace=qos-example --output=yaml
```
The output shows that Kubernetes gave the Pod a QoS class of `BestEffort`:
```yaml
spec:
containers:
...
resources: {}
...
status:
qosClass: BestEffort
```
#### Clean up {#clean-up-besteffort}
Delete your Pod:
```shell
kubectl delete pod qos-demo-3 --namespace=qos-example
```
## Create a Pod that has two Containers
Here is a manifest for a Pod that has two Containers. One container specifies a memory
request of 200 MiB. The other Container does not specify any requests or limits.
apiVersion: v1
kind: Pod
metadata:
name: qos-demo-4
namespace: qos-example
spec:
containers:
- name: qos-demo-4-ctr-1
image: nginx
resources:
requests:
memory: "200Mi"
- name: qos-demo-4-ctr-2
image: redis
Notice that this Pod meets the criteria for QoS class `Burstable`. That is, it does not meet the
criteria for QoS class `Guaranteed`, and one of its Containers has a memory request.
Create the Pod:
```shell
kubectl apply -f https://k8s.io/examples/pods/qos/qos-pod-4.yaml --namespace=qos-example
```
View detailed information about the Pod:
```shell
kubectl get pod qos-demo-4 --namespace=qos-example --output=yaml
```
The output shows that Kubernetes gave the Pod a QoS class of `Burstable`:
```yaml
spec:
containers:
...
name: qos-demo-4-ctr-1
resources:
requests:
memory: 200Mi
...
name: qos-demo-4-ctr-2
resources: {}
...
status:
qosClass: Burstable
```
## Retrieve the QoS class for a Pod
Rather than see all the fields, you can view just the field you need:
```bash
kubectl --namespace=qos-example get pod qos-demo-4 -o jsonpath='{ .status.qosClass}{"\n"}'
```
```none
Burstable
```
## Clean up
Delete your namespace:
```shell
kubectl delete namespace qos-example
```
## What's next
### For app developers
* [Assign Memory Resources to Containers and Pods](/docs/tasks/configure-pod-container/assign-memory-resource/)
* [Assign CPU Resources to Containers and Pods](/docs/tasks/configure-pod-container/assign-cpu-resource/)
### For cluster administrators
* [Configure Default Memory Requests and Limits for a Namespace](/docs/tasks/administer-cluster/manage-resources/memory-default-namespace/)
* [Configure Default CPU Requests and Limits for a Namespace](/docs/tasks/administer-cluster/manage-resources/cpu-default-namespace/)
* [Configure Minimum and Maximum Memory Constraints for a Namespace](/docs/tasks/administer-cluster/manage-resources/memory-constraint-namespace/)
* [Configure Minimum and Maximum CPU Constraints for a Namespace](/docs/tasks/administer-cluster/manage-resources/cpu-constraint-namespace/)
* [Configure Memory and CPU Quotas for a Namespace](/docs/tasks/administer-cluster/manage-resources/quota-memory-cpu-namespace/)
* [Configure a Pod Quota for a Namespace](/docs/tasks/administer-cluster/manage-resources/quota-pod-namespace/)
* [Configure Quotas for API Objects](/docs/tasks/administer-cluster/quota-api-object/)
* [Control Topology Management policies on a node](/docs/tasks/administer-cluster/topology-manager/)
