Updates the configuration for the specified AutoScalingGroup.

NOTE: To update an Auto Scaling group with a launch configuration that has the InstanceMonitoring flag set to False, you must first ensure that collection of group metrics is disabled. Otherwise, calls to UpdateAutoScalingGroup will fail. If you have previously enabled group metrics collection, you can disable collection of all group metrics by calling DisableMetricsCollection.

The new settings are registered upon the completion of this call. Any launch configuration settings take effect on any triggers after this call returns. Scaling activities that are currently in progress aren't affected.

NOTE: If a new value is specified for MinSize without specifying the value for DesiredCapacity, and if the new MinSize is larger than the current size of the Auto Scaling Group, there will be an implicit call to SetDesiredCapacity to set the group to the new MinSize. If a new value is specified for MaxSize without specifying the value for DesiredCapacity, and the new MaxSize is smaller than the current size of the Auto Scaling Group, there will be an implicit call to SetDesiredCapacity to set the group to the new MaxSize. All other optional parameters are left unchanged if not passed in the request.