BroadcastJob

    In the end, BroadcastJob does not consume any resources after each Pod succeeds on every node. This controller is particularly useful when upgrading a software, e.g., Kubelet, or validation check in every node, which is typically needed only once within a long period of time or running an adhoc full cluster inspection script.

    Optionally, a BroadcastJob can keep alive after all Pods on desired nodes complete so that a Pod will be automatically launched for every new node after it is added to the cluster.

    describes the Pod template used to run the job. Note that for the Pod restart policy, only Never or OnFailure is allowed for BroadcastJob.

    Parallelism

    Parallelism specifies the maximal desired number of Pods that should be run at any given time. By default, there’s no limit.

    CompletionPolicy

    CompletionPolicy specifies the controller behavior when reconciling the BroadcastJob.

    Always (default)

    Always policy means the job will eventually complete with either failed or succeeded condition. The following parameters take effect with this policy:

    • ActiveDeadlineSeconds specifies the duration in seconds relative to the startTime that the job may be active before the system tries to terminate it. For example, if ActiveDeadlineSeconds is set to 60 seconds, after the BroadcastJob starts running for 60 seconds, all the running pods will be deleted and the job will be marked as Failed.

    Never

    Type

    Type indicates the type of FailurePolicyType.

    • Continue means the job will be still running, when failed pod is found.
    • FailFast(default) means the job will be failed, when failed pod is found.
    • Pause means the job will be paused, when failed pod is found.

    RestartLimit

    • RestartLimit specifies the number of retries before marking the pod failed. Currently, the number of retries are defined as the aggregated number of restart counts across all Pods created by the job, i.e., the sum of the for all containers in every Pod. If this value exceeds , the job is marked as Failed and all running Pods are deleted. No limit is enforced if RestartLimit is not set.

    Examples

    Monitor BroadcastJob status

    Assuming the cluster has only one node, run kubectl get bcj (shortcut name for BroadcastJob) and we will see the following:

    • Desired : The number of desired Pods. This equals to the number of matched nodes in the cluster.
    • Active: The number of active Pods.
    • SUCCEEDED: The number of succeeded Pods.
    • FAILED: The number of failed Pods.

    ttlSecondsAfterFinished

    Run a BroadcastJob that each Pod computes a pi, with ttlSecondsAfterFinished set to 30. The job will be deleted in 30 seconds after it is finished.

    Run a BroadcastJob that each Pod sleeps for 50 seconds, with activeDeadlineSeconds set to 10 seconds. The job will be marked as Failed after it runs for 10 seconds, and the running Pods will be deleted.

    completionPolicy

    failurePolicy

    restartLimit

    Run a BroadcastJob with FailFast failurePolicy. The job will be failed, when failed pod is found.