1.5.4. jobs

jobs是创建一个或者多个pods的，当数量达到成功的个数阈值时候，任务就结束了， job是可以配置并行的。

1.5.4.1. job样例

 1apiVersion: batch/v1
 2kind: Job
 3metadata:
 4  name: pi
 5spec:
 6  ttlSecondsAfterFinished: 100
 7  template:
 8    spec:
 9      containers:
10      - name: pi
11        image: perl
12        command: ["perl",  "-Mbignum=bpi", "-wle", "print bpi(2000)"]
13      restartPolicy: Never   
14  backoffLimit: 4
15  parallelism: 2

应用一下，通过如下命令查看

kubectl get job
NAME   COMPLETIONS   DURATION   AGE
pi     0/1 of 2      4s         4s

kubectl describe job pi
Name:             pi
Namespace:        default
Selector:         controller-uid=d4d9a0cc-92c2-4d62-b632-9f209f765d16
Labels:           controller-uid=d4d9a0cc-92c2-4d62-b632-9f209f765d16
                        job-name=pi
Annotations:      <none>
Parallelism:      2
Completions:      <unset>
Completion Mode:  NonIndexed
Start Time:       Wed, 06 Oct 2021 11:37:21 +0800
Completed At:     Wed, 06 Oct 2021 11:37:45 +0800
Duration:         24s
Pods Statuses:    0 Running / 2 Succeeded / 0 Failed
Pod Template:
Labels:  controller-uid=d4d9a0cc-92c2-4d62-b632-9f209f765d16
        job-name=pi
Containers:
pi:
    Image:      perl
    Port:       <none>
    Host Port:  <none>
    Command:
    perl
    -Mbignum=bpi
    -wle
    print bpi(2000)
    Environment:  <none>
    Mounts:       <none>
Volumes:        <none>
Events:
Type    Reason            Age   From            Message
----    ------            ----  ----            -------
Normal  SuccessfulCreate  51s   job-controller  Created pod: pi--1-rwc87
Normal  SuccessfulCreate  51s   job-controller  Created pod: pi--1-9r6qf
Normal  Completed         27s   job-controller  Job completed

1.5.4.2. job的并行执行

  • 非并行: 通常启用一个pod,当pod终止后，视为pod完成状态。

  • 具有确定完成计数的job: .spec.completions设为一个非0的，当成功的pod个数达到spec.completions后就认为pod完成。spec.completionmod=indexed时候，每个pod会有一个不同的索引。

  • 带有工作队列冰箱的job: .spec.parallelism 多个pod协同，每个pod从队列取出来部分任务，每个pod都可以确定其他的pod是否完成，job任何pod成功终止，不在创建新的pod。