<p>kube-controller-manager has the following property</p>

<pre><code>-deployment-controller-sync-period duration     Default: 30s
Period for syncing the deployments.
</code></pre>

<p>What does this actually control and what does <code>period for syncing the deployments</code> mean?</p>

<p>Haha most curious thing. You'd expect it does something like controlling how often the controller checks whether the status of Deployment objects are compatible with spec or if there is a change needed.</p>

<p>However currently the controller-manager is notified on changes by the apiserver so it always inherently knows this information already.</p>

<p>There is <a href="https://github.com/kubernetes/kubernetes/issues/71510" rel="nofollow noreferrer">Issue #71510</a> where someone points out that parameter seems to be unused. I've done my own <a href="https://github.com/kubernetes/kubernetes/search?utf8=%E2%9C%93&amp;q=deployment-controller-sync-period&amp;type=" rel="nofollow noreferrer">search for the parameter</a> and a related <a href="https://github.com/kubernetes/kubernetes/search?utf8=%E2%9C%93&amp;q=DeploymentControllerSyncPeriod&amp;type=" rel="nofollow noreferrer">search for the variable</a>. As far as I can tell all of these uses are for copying this value around, conversions, declarations, etc, and none of them actually use it for anything at all.</p>

<p>A good test would be setting it to a year and see what happens. I haven't done that though.</p>
