title: why does google appengine deployment take several minutes to update service
body: <p>I'm using nodejs flexible environment documented <a href="https://cloud.google.com/appengine/docs/flexible/nodejs/configuring-your-app-with-app-yaml" rel="noreferrer">here</a></p>
  
  <p>Nothing fancy in the config</p>
  
  <pre><code>runtime: nodejs
  vm: true
  service: SimpleExpressService
  health_check:
    enable_health_check: False
  automatic_scaling:
    min_num_instances: 1
    max_num_instances: 4
    cool_down_period_sec: 120
    cpu_utilization:
      target_utilization: 0.5
  </code></pre>
  
  <p>Here is my deployment command</p>
  
  <pre><code>gcloud app deploy -q --promote --version $VER
  </code></pre>
  
  <p>Whenever I deploy a new version, almost everything goes really fast. However, the step 'Updating service [SimpleExpressServer]' takes several minutes. </p>
  
  <p>Is there anyway to optimize this step?</p>
  
  <p><a href="https://i.stack.imgur.com/7oUVt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/7oUVt.png" alt="enter image description here"></a></p>