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Update overbooking ratio (Alpha)

Update the overbooking ratio of the created namespace. You can set the overbooking ratio separately for the namespace based on the resource requirements for CPU and memory in the current namespace. This ensures that the limit and request values for containers set by users in this namespace are within a reasonable range, thereby improving the utilization of computing resources.

Resource Ratio: The ratio of limits to requests.
Limits: The maximum amount of resources that a container can use during runtime. The resource usage during container runtime cannot exceed this value.
Requests: The amount of resources that a container requests when it is created. When Kubernetes schedules containers, it judges based on this value and schedules the container to run on a node where the available resources meet the container’s request value. If there is no node that meets the requirement (for example, when the request value is greater than the available resources on the schedulable nodes), the container cannot start normally.

Cautions

If you need to configure the overbooking ratio for virtual machines in a cluster that has enabled node virtualization, you must first disable the overbooking ratio for the cluster or namespace.

Procedure

In the left navigation pane, click Namespaces > Namespaces.
Click the Namespace Name to be updated.
Click Actions > Update Overcommit in the upper-right corner.
Select the overbooking ratio Configuration Method as needed and set the overbooking ratio for CPU or memory for the namespace.

Parameter	Description
Inherit From Cluster	The overbooking ratio for the namespace is set to Inherit From Cluster by default, and the Value displays the overbooking ratio setting for the cluster it belongs to. For example, if the overbooking ratio for CPU and memory in the cluster is set to 4, the overbooking ratio for CPU and memory in the current namespace is both set to 4 by default. When creating an application, the request value for the container is fixed as Specified Limit / Cluster Overcommit. If no limit value is specified, the limit value is the Default Value set in the container quota of the namespace. Example: Assuming that the overbooking ratio for CPU resources in the cluster is set to 4 and the overbooking ratio for the namespace is inherited from the cluster. When a user creates an application and specifies the CPU limit value as 4c, the CPU request value is 4c/4 = 1c.
Custom	The oversubscription ratio of the namespace is based on the Value set by the administrator, and only supports positive integers greater than 1. If not filled in, it means that the current namespace does not have an oversubscription ratio set. For example, if the CPU and memory oversubscription ratios of the cluster are set to 4 and the custom values here are both set to 2, then the CPU and memory oversubscription ratios of the current namespace are both 2. If the custom values here are not filled in, it means that the CPU and memory oversubscription ratios of the current namespace are not set. When creating an application, the requested value of the container is fixed at Specified Limit / Namespace Overcommit. If the limit value is not specified, the limit value is the Default Value set in the container quota of the namespace. Example: Assuming that the cluster oversubscription ratio for CPU resources is 4 and the namespace oversubscription ratio is customized to 2. When a user creates an application and specifies a CPU limit value of 4c, the CPU request value is 4c/2 = 2c.

Parameter

Description

Inherit From Cluster

The overbooking ratio for the namespace is set to Inherit From Cluster by default, and the Value displays the overbooking ratio setting for the cluster it belongs to. For example, if the overbooking ratio for CPU and memory in the cluster is set to 4, the overbooking ratio for CPU and memory in the current namespace is both set to 4 by default.

When creating an application, the request value for the container is fixed as Specified Limit / Cluster Overcommit. If no limit value is specified, the limit value is the Default Value set in the container quota of the namespace.

Example: Assuming that the overbooking ratio for CPU resources in the cluster is set to 4 and the overbooking ratio for the namespace is inherited from the cluster. When a user creates an application and specifies the CPU limit value as 4c, the CPU request value is 4c/4 = 1c.

Custom

The oversubscription ratio of the namespace is based on the Value set by the administrator, and only supports positive integers greater than 1. If not filled in, it means that the current namespace does not have an oversubscription ratio set. For example, if the CPU and memory oversubscription ratios of the cluster are set to 4 and the custom values here are both set to 2, then the CPU and memory oversubscription ratios of the current namespace are both 2. If the custom values here are not filled in, it means that the CPU and memory oversubscription ratios of the current namespace are not set.

When creating an application, the requested value of the container is fixed at Specified Limit / Namespace Overcommit. If the limit value is not specified, the limit value is the Default Value set in the container quota of the namespace.

Example: Assuming that the cluster oversubscription ratio for CPU resources is 4 and the namespace oversubscription ratio is customized to 2. When a user creates an application and specifies a CPU limit value of 4c, the CPU request value is 4c/2 = 2c.

Click Update.

Caution: Updating the oversubscription ratio value does not affect the requested value of the containers that have already been created and are running. After the Pod is rebuilt, the requested value of the containers will be recalculated based on the latest oversubscription ratio.