简介
Priority plugin提供了job、task排序的实现，以及计算牺牲作业的函数preemptableFn。job的排序根据priorityClassName，task的排序依次根据priorityClassName、createTime、id。
场景
当集群运行了多个Job，但资源不足，并且每个Job下有不等数量的Pod等待被调度的时候，如果使用Kubernetes默认调度器，那么最终，具有更多Pod数量的Job将分得更多的集群资源。在这种情况下，volcano-scheduler提供算法支持不同的Job以fair-share的形式共享集群资源。
Priority plugin能够让用户自定义job、task优先级，根据自己的需求在不同层次来定制调度策略。根据job的priorityClassName在应用层面进行优先级排序，例如集群中有金融场景、物联网监控场景等需要较高实时性的应用，Priority plugin能够保证其优先得到调度。
/home/margin/code/volcano/pkg/scheduler/plugins/priority/priority_test.go
piVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
annotations:
controller-gen.kubebuilder.io/version: v0.15.0
name: podgroups.scheduling.volcano.sh
spec:
group: scheduling.volcano.sh
names:
kind: PodGroup
listKind: PodGroupList
plural: podgroups
shortNames:
- pg
- podgroup-v1beta1
singular: podgroup
scope: Namespaced
versions:
- additionalPrinterColumns:
- jsonPath: .status.phase
name: STATUS
type: string - jsonPath: .spec.minMember
name: minMember
type: integer - jsonPath: .status.running
name: RUNNINGS
type: integer - jsonPath: .metadata.creationTimestamp
name: AGE
type: date - jsonPath: .spec.queue
name: QUEUE
priority: 1
type: string
name: v1beta1
schema:
openAPIV3Schema:
description: PodGroup is a collection of Pod; used for batch workload.
properties:
apiVersion:
description: |-
APIVersion defines the versioned schema of this representation of an object.
Servers should convert recognized schemas to the latest internal value, and
may reject unrecognized values.
More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
type: string
kind:
description: |-
Kind is a string value representing the REST resource this object represents.
Servers may infer this from the endpoint the client submits requests to.
Cannot be updated.
In CamelCase.
More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
type: string
metadata:
type: object
spec:
description: |-
Specification of the desired behavior of the pod group.
More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#spec-and-status
properties:
minMember:
description: |-
MinMember defines the minimal number of members/tasks to run the pod group;
if there's not enough resources to start all tasks, the scheduler
will not start anyone.
format: int32
type: integer
minResources:
additionalProperties:
anyOf:
- type: integer
- type: string
pattern: ^(+|-)?(([0-9]+(.[0-9])?)|(.[0-9]+))(([KMGTPE]i)|[numkMGTPE]|(eE?(([0-9]+(.[0-9])?)|(.[0-9]+))))?$
x-kubernetes-int-or-string: true
description: |-
MinResources defines the minimal resource of members/tasks to run the pod group;
if there's not enough resources to start all tasks, the scheduler
will not start anyone.
type: object
minTaskMember:
additionalProperties:
format: int32
type: integer
description: |-
MinTaskMember defines the minimal number of pods to run each task in the pod group;
if there's not enough resources to start each task, the scheduler
will not start anyone.
type: object
priorityClassName:
description: |-
If specified, indicates the PodGroup's priority. "system-node-critical" and
"system-cluster-critical" are two special keywords which indicate the
highest priorities with the former being the highest priority. Any other
name must be defined by creating a PriorityClass object with that name.
If not specified, the PodGroup priority will be default or zero if there is no
default.
type: string
- jsonPath: .status.phase
