K
Q

Kubernetes Cron Job Terminate Pod before creation of next schedule

7/29/2019

I have a Kubernetes Cron Job for running a scheduled task every 5 minutes. I want to make sure that when a new pod is created at next schedule time, the earlier pod should have been terminated. The earlier pod should get terminated before creation of new. Can Kubernetes terminate the earlier pod before creation of new?

My yaml is:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: my-scheduled
spec:
  schedule: "*/5 * * * *"
  concurrencyPolicy: Forbid
  successfulJobsHistoryLimit: 1
  failedJobsHistoryLimit: 1
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: cmm-callout
            env:
              - name: SCHEDULED
                value: "true"
            livenessProbe:
              httpGet:
                path: /myapp/status
                port: 7070
                scheme: HTTPS
              initialDelaySeconds: 120
              timeoutSeconds: 30
              periodSeconds: 120                
            image: gcr.io/projectid/folder/my-app:9.0.8000.34
          restartPolicy: Never

How can I make sure the earlier pod is terminated before new is created?

-- user5155835
google-cloud-platform
google-kubernetes-engine
kubernetes
yaml

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2 Answers

7/30/2019

Did you try to set the concurrencyPolicy to Replace? Forbid means to skip the new job run if the previous one hasn't finished yet.

https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/#concurrency-policy

Allow (default): The cron job allows concurrently running jobs

Forbid: The cron job does not allow concurrent runs; if it is time for a new job run and the previous job run hasn’t finished yet, the cron job skips the new job run

Replace: If it is time for a new job run and the previous job run hasn’t finished yet, the cron job replaces the currently running job run with a new job run

-- Hang Du
Source: StackOverflow
8/5/2019

If i understood your case correctly (the earlier pod should have been terminated before creation of new one).

1. Please use spec.jobTemplate.spec.activeDeadlineSeconds instead.

By setting this parameter once a Job reaches activeDeadlineSeconds - all of running Pods will be terminated and the Job status will become type: Failed with reason DeadlineExceeded.

example:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/5 * * * *"
  jobTemplate:
    spec:
      activeDeadlineSeconds: 60
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            args:
            - /bin/sh
            - -c
            - date; echo Hello from the Kubernetes cluster && sleep 420
          restartPolicy: Never

2. The second solution is to set-up concurrencyPolicy. and replace the currently running job with a new job.

example:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: hello
spec:
  schedule: "*/2 * * * *"
  concurrencyPolicy: Replace
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: busybox
            args:
            - /bin/sh
            - -c
            - date; echo Hello from the Kubernetes cluster && sleep 420
          restartPolicy: Never

Resources:

-- Hanx
Source: StackOverflow