func resourceAwsAutoscalingGroupUpdate(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).autoscalingconn

	opts := autoscaling.UpdateAutoScalingGroupInput{
		AutoScalingGroupName: aws.String(d.Id()),
	}

	if d.HasChange("default_cooldown") {
		opts.DefaultCooldown = aws.Int64(int64(d.Get("default_cooldown").(int)))
	}

	if d.HasChange("desired_capacity") {
		opts.DesiredCapacity = aws.Int64(int64(d.Get("desired_capacity").(int)))
	}

	if d.HasChange("launch_configuration") {
		opts.LaunchConfigurationName = aws.String(d.Get("launch_configuration").(string))
	}

	if d.HasChange("min_size") {
		opts.MinSize = aws.Int64(int64(d.Get("min_size").(int)))
	}

	if d.HasChange("max_size") {
		opts.MaxSize = aws.Int64(int64(d.Get("max_size").(int)))
	}

	if d.HasChange("health_check_grace_period") {
		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
	}

	if d.HasChange("health_check_type") {
		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
		opts.HealthCheckType = aws.String(d.Get("health_check_type").(string))
	}

	if d.HasChange("vpc_zone_identifier") {
		opts.VPCZoneIdentifier = expandVpcZoneIdentifiers(d.Get("vpc_zone_identifier").(*schema.Set).List())
	}

	if d.HasChange("availability_zones") {
		if v, ok := d.GetOk("availability_zones"); ok && v.(*schema.Set).Len() > 0 {
			opts.AvailabilityZones = expandStringList(d.Get("availability_zones").(*schema.Set).List())
		}
	}

	if d.HasChange("placement_group") {
		opts.PlacementGroup = aws.String(d.Get("placement_group").(string))
	}

	if d.HasChange("termination_policies") {
		// If the termination policy is set to null, we need to explicitly set
		// it back to "Default", or the API won't reset it for us.
		// This means GetOk() will fail us on the zero check.
		v := d.Get("termination_policies")
		if len(v.([]interface{})) > 0 {
			opts.TerminationPolicies = expandStringList(v.([]interface{}))
		} else {
			// Policies is a slice of string pointers, so build one.
			// Maybe there's a better idiom for this?
			log.Printf("[DEBUG] Explictly setting null termination policy to 'Default'")
			pol := "Default"
			s := make([]*string, 1, 1)
			s[0] = &pol
			opts.TerminationPolicies = s
		}
	}

	if err := setAutoscalingTags(conn, d); err != nil {
		return err
	} else {
		d.SetPartial("tag")
	}

	log.Printf("[DEBUG] AutoScaling Group update configuration: %#v", opts)
	_, err := conn.UpdateAutoScalingGroup(&opts)
	if err != nil {
		d.Partial(true)
		return fmt.Errorf("Error updating Autoscaling group: %s", err)
	}

	if d.HasChange("load_balancers") {

		o, n := d.GetChange("load_balancers")
		if o == nil {
			o = new(schema.Set)
		}
		if n == nil {
			n = new(schema.Set)
		}

		os := o.(*schema.Set)
		ns := n.(*schema.Set)
		remove := expandStringList(os.Difference(ns).List())
		add := expandStringList(ns.Difference(os).List())

		if len(remove) > 0 {
			_, err := conn.DetachLoadBalancers(&autoscaling.DetachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    remove,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}

		if len(add) > 0 {
			_, err := conn.AttachLoadBalancers(&autoscaling.AttachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    add,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}
	}

	return resourceAwsAutoscalingGroupRead(d, meta)
}
func resourceAwsAutoscalingGroupUpdate(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).autoscalingconn
	shouldWaitForCapacity := false

	opts := autoscaling.UpdateAutoScalingGroupInput{
		AutoScalingGroupName: aws.String(d.Id()),
	}

	if d.HasChange("default_cooldown") {
		opts.DefaultCooldown = aws.Int64(int64(d.Get("default_cooldown").(int)))
	}

	if d.HasChange("desired_capacity") {
		opts.DesiredCapacity = aws.Int64(int64(d.Get("desired_capacity").(int)))
		shouldWaitForCapacity = true
	}

	if d.HasChange("launch_configuration") {
		opts.LaunchConfigurationName = aws.String(d.Get("launch_configuration").(string))
	}

	if d.HasChange("min_size") {
		opts.MinSize = aws.Int64(int64(d.Get("min_size").(int)))
		shouldWaitForCapacity = true
	}

	if d.HasChange("max_size") {
		opts.MaxSize = aws.Int64(int64(d.Get("max_size").(int)))
	}

	if d.HasChange("health_check_grace_period") {
		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
	}

	if d.HasChange("health_check_type") {
		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
		opts.HealthCheckType = aws.String(d.Get("health_check_type").(string))
	}

	if d.HasChange("vpc_zone_identifier") {
		opts.VPCZoneIdentifier = expandVpcZoneIdentifiers(d.Get("vpc_zone_identifier").(*schema.Set).List())
	}

	if d.HasChange("availability_zones") {
		if v, ok := d.GetOk("availability_zones"); ok && v.(*schema.Set).Len() > 0 {
			opts.AvailabilityZones = expandStringList(v.(*schema.Set).List())
		}
	}

	if d.HasChange("placement_group") {
		opts.PlacementGroup = aws.String(d.Get("placement_group").(string))
	}

	if d.HasChange("termination_policies") {
		// If the termination policy is set to null, we need to explicitly set
		// it back to "Default", or the API won't reset it for us.
		if v, ok := d.GetOk("termination_policies"); ok && len(v.([]interface{})) > 0 {
			opts.TerminationPolicies = expandStringList(v.([]interface{}))
		} else {
			log.Printf("[DEBUG] Explictly setting null termination policy to 'Default'")
			opts.TerminationPolicies = aws.StringSlice([]string{"Default"})
		}
	}

	if err := setAutoscalingTags(conn, d); err != nil {
		return err
	} else {
		d.SetPartial("tag")
	}

	log.Printf("[DEBUG] AutoScaling Group update configuration: %#v", opts)
	_, err := conn.UpdateAutoScalingGroup(&opts)
	if err != nil {
		d.Partial(true)
		return fmt.Errorf("Error updating Autoscaling group: %s", err)
	}

	if d.HasChange("load_balancers") {

		o, n := d.GetChange("load_balancers")
		if o == nil {
			o = new(schema.Set)
		}
		if n == nil {
			n = new(schema.Set)
		}

		os := o.(*schema.Set)
		ns := n.(*schema.Set)
		remove := expandStringList(os.Difference(ns).List())
		add := expandStringList(ns.Difference(os).List())

		if len(remove) > 0 {
			_, err := conn.DetachLoadBalancers(&autoscaling.DetachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    remove,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}

		if len(add) > 0 {
			_, err := conn.AttachLoadBalancers(&autoscaling.AttachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    add,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}
	}

	if shouldWaitForCapacity {
		waitForASGCapacity(d, meta, capacitySatifiedUpdate)
	}

	if d.HasChange("enabled_metrics") {
		updateASGMetricsCollection(d, conn)
	}

	return resourceAwsAutoscalingGroupRead(d, meta)
}
func resourceAwsAutoscalingGroupUpdate(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).autoscalingconn

	opts := autoscaling.UpdateAutoScalingGroupInput{
		AutoScalingGroupName: aws.String(d.Id()),
	}

	if d.HasChange("default_cooldown") {
		opts.DefaultCooldown = aws.Long(int64(d.Get("default_cooldown").(int)))
	}

	if d.HasChange("desired_capacity") {
		opts.DesiredCapacity = aws.Long(int64(d.Get("desired_capacity").(int)))
	}

	if d.HasChange("launch_configuration") {
		opts.LaunchConfigurationName = aws.String(d.Get("launch_configuration").(string))
	}

	if d.HasChange("min_size") {
		opts.MinSize = aws.Long(int64(d.Get("min_size").(int)))
	}

	if d.HasChange("max_size") {
		opts.MaxSize = aws.Long(int64(d.Get("max_size").(int)))
	}

	if d.HasChange("health_check_grace_period") {
		opts.HealthCheckGracePeriod = aws.Long(int64(d.Get("health_check_grace_period").(int)))
	}

	if d.HasChange("health_check_type") {
		opts.HealthCheckGracePeriod = aws.Long(int64(d.Get("health_check_grace_period").(int)))
		opts.HealthCheckType = aws.String(d.Get("health_check_type").(string))
	}

	if d.HasChange("vpc_zone_identifier") {
		opts.VPCZoneIdentifier = expandVpcZoneIdentifiers(d.Get("vpc_zone_identifier").(*schema.Set).List())
	}

	if d.HasChange("availability_zones") {
		if v, ok := d.GetOk("availability_zones"); ok && v.(*schema.Set).Len() > 0 {
			opts.AvailabilityZones = expandStringList(d.Get("availability_zones").(*schema.Set).List())
		}
	}

	if err := setAutoscalingTags(conn, d); err != nil {
		return err
	} else {
		d.SetPartial("tag")
	}

	log.Printf("[DEBUG] AutoScaling Group update configuration: %#v", opts)
	_, err := conn.UpdateAutoScalingGroup(&opts)
	if err != nil {
		d.Partial(true)
		return fmt.Errorf("Error updating Autoscaling group: %s", err)
	}

	if d.HasChange("load_balancers") {

		o, n := d.GetChange("load_balancers")
		if o == nil {
			o = new(schema.Set)
		}
		if n == nil {
			n = new(schema.Set)
		}

		os := o.(*schema.Set)
		ns := n.(*schema.Set)
		remove := expandStringList(os.Difference(ns).List())
		add := expandStringList(ns.Difference(os).List())

		if len(remove) > 0 {
			_, err := conn.DetachLoadBalancers(&autoscaling.DetachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    remove,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}

		if len(add) > 0 {
			_, err := conn.AttachLoadBalancers(&autoscaling.AttachLoadBalancersInput{
				AutoScalingGroupName: aws.String(d.Id()),
				LoadBalancerNames:    add,
			})
			if err != nil {
				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
			}
		}
	}

	return resourceAwsAutoscalingGroupRead(d, meta)
}