title: instance latency in Google App Engine
body: <p>I am running a free application and using 1 max idle instance using GAE's Python runtime.</p>
  
  <p>According to <a href="http://code.google.com/appengine/docs/adminconsole/instances.html" rel="nofollow">http://code.google.com/appengine/docs/adminconsole/instances.html</a>, </p>
  
  <blockquote>
    <p>Your application's latency has the biggest impact on the number of
    instances needed to serve your traffic. If you service requests
    quickly, a single instance can handle a lot of requests.</p>
  </blockquote>
  
  <p>This seems to suggest that adjusting the slider in 'Application Settings' to minimum latency would be best.</p>
  
  <p>However, according to <a href="http://code.google.com/appengine/docs/adminconsole/performancesettings.html#Setting_the_Minimum_Pending_Latency" rel="nofollow">http://code.google.com/appengine/docs/adminconsole/performancesettings.html#Setting_the_Minimum_Pending_Latency</a>,</p>
  
  <p>it seems like having a high latency is good for preventing load spikes from spinning up new instances.</p>
  
  <p>So is latency basically a tradeoff between ability to respond to request spikes (high latency) vs. number of requests handled over a given time period (low latency)?</p>