title: What does the various options in time aggregation field mean?
body: <p>I am trying to use Scale Rule for the first time and am trying to fiddle with "Storage Queue" resource. While trying to set options I see following options in "Time Aggregation": Minimum, Maximum, Average, Total and Last.
  What I learnt is that the value selected from TimeAggregation will be used for the specified "duration" and will be compared against the specified "Threshold".
  However I fail to understand what is the sampling interval for the data that it will try to do. Also consider the following example:</p>
  
  <p>Say I have the following rule:
  If AppxMsgCount >=15, increase the instance count by 3
  where,
  Threshold = 15 and time aggregation is set to "Average"</p>
  
  <p>System state:
  AppxMsgCount = 20
  Current Instance Count = 2</p>
  
  <p>So the first time the auto scale gets kicked in with the above system state, the instance count gets increased to 5.</p>
  
  <p>Now, with the increased instances AppxMsgCount supposed to come down? My hunch says it must be but then what should be the maths for it? Is it 20*2/5 ?</p>
  
  <p>Second thing what does the other options mean here, and when should they be used - i.e. when should I be using total vs when should I be using average</p>
  
  <p>It will be helpful if I can get some link for reference.</p>