<p>According to <a href="https://kubernetes.io/docs/concepts/workloads/controllers/job/#clean-up-finished-jobs-automatically" rel="nofollow noreferrer">the docs</a>:</p>
<blockquote>
<p>Keeping them (completed jobs) around in the system will put pressure on the API server.</p>
</blockquote>
<p>I understand that regularly going through a long list of completed jobs, only to find out that none needs to run, is a waste of CPU, as well as stopped pods are a waste of disk space, but how much of a problem is this really?</p>
<p>Must I clean them up ASAP because the cluster goes down otherwise?</p>

<p>I think the boundary number will be floating around 150k:
<a href="https://kubernetes.io/docs/setup/best-practices/cluster-large/#support" rel="nofollow noreferrer">https://kubernetes.io/docs/setup/best-practices/cluster-large/#support</a> (see  total pods)</p>
<p>There's a boundary number in any case, so it's a good idea to add some cleaner, especially if you know what is safe to clean.</p>
