title: How databricks do auto scaling for a cluster
body: <p>I have a databricks cluster setup with auto scale upto 12 nodes. 
  I have often observed databricks scaling cluster from 6 to 8, then 8 to 11 and then 11 to 14 nodes.</p>
  
  <p>So my queries -
  1. Why is it picking up 2-3 nodes to be added at one go 
  2. Why auto scale is triggered as I see not many jobs are active or heavy processing on cluster. CPU usage is pretty low.
  3. While auto scaling why is it leaving notebook in waiting state<br>
  4. Why is it taking up to 8-10 min to auto scale </p>
  
  <p>Thanks</p>
  
  <p>I am trying to investigate why data bricks is auto scaling cluster when its not needed</p>