Google ACE Deploy a web application on Compute Engine Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Use a single large instance and rely on Cloud Load Balancing

  Why it's wrong here

  A single large instance can only scale vertically, hitting the machine type's vCPU and memory ceiling, and Cloud Load Balancing merely routes traffic to whatever backend instances exist—it does not create new VMs or trigger horizontal scaling. This architecture also creates a single point of failure, since a single instance outage takes the entire application down unless a separate manual failover process is implemented.

• ✗

  Use an unmanaged instance group and manually add or remove instances

  Why it's wrong here

  Unmanaged instance groups require you to manually create, provision, and register each VM instance, and they do not support autoscaling at all. You would have to continuously monitor CPU utilization yourself and then manually add or remove instances, which defeats the purpose of decoupling scaling from operational effort. Google Cloud Autoscaler only works with managed instance groups, so an unmanaged group cannot automatically adjust capacity in response to load.

• ✓

  Use a managed instance group with an autoscaling policy based on CPU utilization

  Why this is correct

  A managed instance group (MIG) automatically creates and manages instances from an instance template, and attaching an autoscaler with a CPU utilization target lets the group dynamically add or remove VMs to keep average CPU near the desired threshold. The autoscaler continually polls Cloud Monitoring metrics and can also use load balancing signals, making it appropriate for a Compute Engine web application that needs horizontal scaling. MIGs integrate with Cloud Load Balancing and instance health checks, enabling both scale-out and automatic recovery of unhealthy instances.

• ✗

  Deploy the application on App Engine Standard environment

  Why it's wrong here

  App Engine Standard is a fully managed serverless platform that abstracts away virtual machines entirely—you deploy application code and Google manages the underlying runtime and infrastructure. The question explicitly requires deployment on Compute Engine, so App Engine Standard is the wrong service; even though it scales automatically, it does not give you direct control over VMs, persistent disks, or the OS, which are key aspects of Compute Engine-based architecture.

Go deeper

Related to this question