Google Associate Cloud Engineer

Explanation

To have exactly one VM running in a Managed Instance Group (MIG), you should set the MIG size to 1.

Why option B is correct:

• Setting the Managed Instance Group size to 1 ensures that exactly one instance is always running
• This is the direct configuration parameter that controls the number of instances in a MIG
• The MIG will automatically maintain exactly one instance, replacing it if it fails

Why other options are incorrect:

• Option A (Enable autoscaling min/max = 1): While this would keep exactly one instance, autoscaling is designed for dynamic scaling based on metrics, not for fixed instance counts. It's more complex and less direct than simply setting the MIG size.
• Option C (Use multiple zones): This is about high availability across zones, not about controlling the number of instances. A MIG can span multiple zones but still have multiple instances.
• Option D (Use Cloud Run): Cloud Run is a serverless container platform, not a VM-based solution. This doesn't address the requirement for a Managed Instance Group with VMs.

Best Practice: When you need a fixed number of instances in a MIG, always use the size parameter rather than autoscaling with identical min/max values, as it's simpler and more straightforward for the intended purpose.