title: AWS Boto3 method "update_auto_scaling_group()" intermittent silent fail
body: <p>I'm trying to update my Auto Scaling Group <strong>"DesiredCapacity"</strong> using python Boto3 command named <strong>"update_auto_scaling_group"</strong>. Generally it works fine but sometimes this command silently fails and doesn't update anything, the response of this method does not give me any clue on what is happening since it's "http Code 200-OK". I'm also making sure that the MaxSize of the auto scaling group is greater than the desired.</p>
  
  <pre><code>response = client.update_auto_scaling_group(AutoScalingGroupName="AutoScalingGroupName",
  DesiredCapacity=2, MaxSize=3)
  </code></pre>
  
  <p>Request response.</p>
  
  <pre><code>{
  'RequestId': '70e5673c-aaad-11t9-9edd-12345678aee1', 
  'HTTPStatusCode': 200, 
  'HTTPHeaders': {'x-amzn-requestid': '70e5673c-aaad-11t9-9edd-12345678aee1', 'content-type': 'text/xml', 'content-length': '231', 'date': 'Tue, 05 Nov 2019 18:52:39 GMT'}, 
  'RetryAttempts': 0
  }
  </code></pre>
  
  <p>I read all the documentation regarding the possible fails on this method, but it says that in all cases of error the response http code is different from 200. 
  <a href="https://docs.aws.amazon.com/pt_br/autoscaling/ec2/APIReference/API_UpdateAutoScalingGroup.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/pt_br/autoscaling/ec2/APIReference/API_UpdateAutoScalingGroup.html</a></p>
  
  <p>I also have a function to check if the value of the desired capacity has changed correctly and it always falsely responds that it was updated. When I check the Desired capacity on AWS console I see that it hasn't change.</p>
  
  <pre><code>def is_autoscaling_updated(desired: int, configs: ConfigParameters):
  client = boto3.client(
  'autoscaling',
  aws_access_key_id="myAccessKeyId",
  aws_secret_access_key="mySecretAccessKey",
  region_name="myRegion"
  )
  
  response = client.describe_auto_scaling_groups(AutoScalingGroupNames=
  ["MyAutoScalingGroupName"])
  
  desired_response = response['AutoScalingGroups'][0]['DesiredCapacity']
  
  if desired_response != desired:
     return False
  
  return True
  </code></pre>
  
  <p>Can someone please help me with this?</p>