When testing changes to a managed instance group handling a high-priority workload, what should you enable to maintain sufficient capacity?

Enabling autoscaling to "Only scale out" while making changes is a strategic approach to maintain sufficient capacity in a managed instance group handling high-priority workloads. This setting allows the instance group to dynamically increase its size in response to demand, ensuring that there are enough resources available to handle workloads even during updates or changes.

The rationale behind this choice lies in the nature of high-priority workloads, which require consistent performance and availability. By allowing the group to only scale out, you prevent situations where the workload might suffer due to insufficient instances during the testing phase of your changes. This ensures that the system can accommodate increased demand without losing capacity, leading to a smoother transition as new changes are tested.

Other options may present potential limitations. For example, changing the managed instance group to run in multiple zones can enhance redundancy and availability, but it doesn't directly address capacity management during changes. Temporarily disabling autoscaling can lead to insufficient resources and possible service disruptions. Enabling predictive autoscaling could adjust capacity based on anticipated future demand, but it may not react as quickly as needed during active changes. Thus, "Only scale out" provides a more immediate and reliable safeguard for high-priority workloads during testing and changes.