title: What does Kubernetes cronjobs `startingDeadlineSeconds` exactly mean?
body: <p>In Kubernetes <a href="https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/" rel="noreferrer">cronjobs</a>, It is stated in the <a href="https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/#cron-job-limitations" rel="noreferrer">limitations section</a> that </p>
  
  <blockquote>
    <p>Jobs may fail to run if the CronJob controller is not running or broken for a span of time from before the start time of the CronJob to start time plus startingDeadlineSeconds, or if the span covers multiple start times and concurrencyPolicy does not allow concurrency.</p>
  </blockquote>
  
  <p>What I understand from this is that, If the <code>startingDeadlineSeconds</code> is set to <code>10</code> and the cronjob couldn't start for some reason at its scheduled time, then it can still be attempted to start again as long as those <code>10</code> seconds haven't passed, however, after the <code>10</code> seconds, it for sure won't be started, is this correct?</p>
  
  <p>Also, If I have <code>concurrencyPolicy</code> set to <code>Forbid</code>, does K8s count it as a fail if a cronjob tries to be scheduled, when there is one already running?</p>