Cloud Digital Leader Google Cloud Products and Services 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 regional Persistent Disk

  Why this is correct

  Regional Persistent Disk synchronously replicates data across two zones in the selected region, providing zone-failure resilience with write-consistent, read-after-write semantics. This makes it the correct choice for a critical stateful application because VM instances can be recreated or failed over to another zone while retaining the same disk data. It supports live migration, snapshots, and resizing, and is the recommended block storage for applications that require high availability without sacrificing durability.

• ✗

  Place instances in a zonal managed instance group

  Why it's wrong here

  A zonal managed instance group runs all its instances in a single zone, meaning the entire group is unavailable if that zone experiences an outage. Even if the group has multiple instances and auto-healing, it cannot provide cross-zone failover or maintain quorum because the compute capacity is not spread across zones. For a critical stateful application that must survive a zonal failure, a zonal MIG is insufficient because it does not offer the geographic or availability-zone redundancy needed for high availability.

• ✗

  Enable object versioning on a Cloud Storage bucket

  Why it's wrong here

  Enabling object versioning on a Cloud Storage bucket is designed to preserve, retrieve, and restore previous versions of objects in a bucket, which is a form of data protection for object storage. However, a running application's stateful data on a Compute Engine instance is typically stored on block Persistent Disks, not on Cloud Storage objects, and Cloud Storage cannot be attached as a file system or boot disk without additional layers like FUSE adapters. Object versioning does not provide block-level replication or low-latency I/O, so it cannot replace Persistent Disks for a critical VM-based stateful workload.

• ✓

  Place instances in a regional managed instance group

  Why this is correct

  A regional managed instance group distributes instances across multiple zones within a region, so if one zone fails, the remaining instances in other zones continue serving traffic, providing high availability for the compute layer. When combined with regional Persistent Disks, a regional MIG supports stateful applications by ensuring that at least one instance is always running and can access the same replicated data. This approach directly addresses the requirement to run a critical stateful application in a way that tolerates zonal outages, making it a correct architectural component.

• ✗

  Use zonal Persistent Disk

  Why it's wrong here

  Zonal Persistent Disk stores data in a single zone, so it becomes inaccessible if that zone has a service disruption, potentially leading to data loss or extended downtime. While zonal Persistent Disks are cheaper and suitable for many workloads, they lack the synchronous cross-zone replication that regional Persistent Disks provide. For a critical stateful application where availability and durability are paramount, using a zonal disk creates a single point of failure that violates the high-availability requirement.

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