Scheduling Tasks

You can execute short-lived workflows by running them as Tasks. Running Tasks describes how to run Tasks under Apps.

You can also schedule Tasks to run at recurring intervals specified using the unix-cron format. With scheduled Tasks, you first push an App running the Task as you do with an unscheduled Task, then create a Job to schedule the Task.

You can define a schedule so that your Task runs multiple times a day, or on specific days and months.

Push an App for running scheduled Tasks

  1. Clone the test-app repo.

    git clone https://github.com/cloudfoundry-samples/test-app test-app
cd test-app

  2. Push the App.

    Push the App with the kf push APP_NAME --task command. The --task flag indicates that the App is meant to be used for running Tasks, and thus no routes will be created on the App and it will not be deployed as a long-running application.

    kf push test-app --task

  3. Confirm that no App instances or routes were created by listing the App.

    kf apps

    Notice that the App is not started and has no URLs.

    Listing Apps in Space: test-space
Name                     Instances  Memory  Disk  CPU   URLs
test-app                 stopped    1Gi     1Gi   100m  <nil>

Create a Job

To run a Task on a schedule, you must first create a Job that describes the Task.

kf create-job test-app test-job "printenv"

The Job starts suspended, or unscheduled, and does not create Tasks until it is manually executed by kf run-job or scheduled by kf schedule-task.

Running manually

Jobs can be run ad hoc similar to running Tasks by kf run-task. This option can be useful for testing the Job before scheduling or running as needed in addition to the schedule.

kf run-job test-job

This command runs the Task defined by the Job a single time immediately.

Scheduling a Job

To schedule the Job for execution, you must provide a unix-cron schedule in the kf schedule-job command.

kf schedule-job test-job "* * * * *"

This command triggers the Job to automatically create Tasks on the specified schedule. In this example a Task runs every minute.

You can update a Job's schedule by running kf schedule-task with a new schedule. Jobs in Kf can only have a single cron schedule. This differs from the PCF Scheduler which allows multiple schedules for a single Job. If you require multiple cron schedules then you can achieve that with multiple Jobs.

Managing Jobs and Schedules

View all Jobs, both scheduled and unscheduled, in the current Space by using the kf jobs command.

$ kf jobs
Listing Jobs in Space: test space
Name               Schedule    Suspend  LastSchedule  Age  Ready  Reason
test-job           * * * * *   <nil>    16s           2m   True   <nil>
unscheduled-job    0 0 30 2 *  true     16s           2m   True   <nil>

Additionally, you can view only Jobs which are actively scheduled with the kf job-schedules command.

$ kf job-schedules
Listing job schedules in Space: test space
Name           Schedule   Suspend  LastSchedule  Age  Ready  Reason
test-job       * * * * *  <nil>    16s           2m   True   <nil>

Notice how the unscheduled-job is not listed in the kf job-schedules output.

Cancelling a Job's schedule

You can stop a scheduled Job with the kf delete-job-schedule command.

kf delete-job-schedule test-job

This command suspends the Job and stops it from creating Tasks on the previous schedule. The Job is not deleted and can be scheduled again by kf schedule-job to continue execution.

Delete a Job

The entire Job can be deleted with the kf delete-job command.

kf delete-job test-job

This command deletes the Job and all Tasks which were created by the Job, both scheduled and manual executions. If any Tasks are still running, this command forcefully deletes them.

If you want to ensure that running Tasks are not interrupted, then first delete the Jobs schedule with kf delete-job-schedule, wait for all Tasks to complete, and then delete the job by calling kf delete-job.