<p>In Kubernetes layout, first I have created cluster of nodes (consider as physical PC). Now inside each PC there can be multiple POD. Inside each POD there is again multiple container. Each container can holds multiple application (but ideally should restrict to one).</p>

<p>Now if the above statement is true: </p>

<ol>
<li>We are having cluster around node but inside nodes we are having different application? </li>
<li>For scale-up/down or self-healing we are increasing Node only or POD also?</li>
</ol>

Baharul
<p>Your above understanding is correct </p>

<blockquote>
  <p>1)then we are having cluster around node but inside nodes we are
  having different application?</p>
</blockquote>

<p>Yes you can say we have different application inside nodes but you can also say that we have different application inside kubernetes cluster and kubernetes scheduler schedule those application in different node  in kubernetes cluster as per the resource availability like CPU,ram.</p>

<blockquote>
  <p>2) For scale-up/down or self-healing we are increasing Node only or
  POD</p>
</blockquote>

<p>scale-up/down or self-healing of application in  kubernetes increase/decrease the pod done by the kubernetes scheduler and in case if some pod died kuberenetes scheduler schedule new replacement pod in new node/same node as part of self healing.</p>

<p>Kubernetes use HPA(Horizontal Pod Autoscaller) for scale-up/down application it will increase/decrease the pod according to the metrics define like cpu,memory or custom metrics .</p>
