Google PCA Ensure solution and operations reliability Practice Test 5 — 15 Questions

Question 1

You are designing a Dataflow streaming pipeline for real-time event processing. The pipeline must be cost-effective while tolerating worker failures without data loss. Which configuration should you use?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use a Dataflow streaming job with Streaming Engine, autoscaling, and non-preemptible workers.. A standard Dataflow streaming job (non-FlexRS) with non-preemptible workers and Streaming Engine enabled provides failure tolerance without data loss. Non-preemptible workers are not subject to termination, reducing failure frequency, and Streaming Engine's durable state checkpointing preserves progress across any worker failures. While preemptible workers are cheaper, they introduce higher failure risk; FlexRS is batch-only and cannot be used for streaming pipelines. Therefore, option D is the correct choice for a cost-effective (via autoscaling) and reliable streaming pipeline.

Answer

Use a batch Dataflow job with preemptible workers.

Answer

Use high-memory machine types for all workers to avoid preemption.

Answer

Use FlexRS with preemptible workers and enable streaming engine.

Question 2

Your company runs a critical multi-tier application: a global HTTP(S) load balancer, multiple regional managed instance groups (MIGs) for the web tier, and Cloud Spanner for the data tier. You need to design for zone-level and region-level failures. What architecture ensures the highest availability?

Accepted Answer

Use a global HTTP(S) load balancer with regional MIGs in multiple regions, each spanning zones, and a multi-region Cloud Spanner instance.. It combines a global HTTP(S) load balancer (which can route traffic to healthy backends across regions), regional MIGs that span multiple zones within each region (providing zone-level redundancy), and a multi-region Cloud Spanner instance (which provides synchronous replication across regions for strong consistency and automatic failover). This architecture ensures that if an entire zone or region fails, traffic is automatically redirected to healthy backends in other zones/regions, and Spanner continues to serve reads and writes without manual intervention.

Answer

Use a global HTTP(S) load balancer with a single global MIG and a multi-region Cloud Spanner instance.

Answer

Use a global HTTP(S) load balancer with a single zonal MIG and Cloud Spanner single-region.

Answer

Use a regional HTTP(S) load balancer with a regional MIG and Cloud SQL with cross-region replication.

Question 3

You are responsible for incident management for a production service. You want to reduce manual toil during the initial response to common issues like high latency. What is the best approach?

Accepted Answer

Use Cloud Monitoring to trigger a Cloud Function that performs automated checks and rolls back the last deployment if latency spikes.. It directly reduces manual toil by automating the initial response to common issues like high latency. Cloud Monitoring triggers a Cloud Function that performs automated checks and, if latency spikes, rolls back the last deployment, eliminating the need for human intervention during the critical first response phase.

Answer

Set up Cloud Monitoring alerts with email notifications to the on-call engineer.

Answer

Create detailed runbooks and require the on-call to follow them step by step.

Answer

Enable Cloud Logging and set up a custom dashboard for the on-call.

Question 4

You are deploying a stateless web application on Compute Engine. Which TWO actions improve availability? (Choose 2)

Accepted Answer

Use a regional managed instance group.. A regional managed instance group (MIG) distributes instances across multiple zones within a region, ensuring that if one zone fails, traffic is automatically routed to healthy instances in other zones. This provides high availability by eliminating a single zone of failure, which is critical for stateless web applications that can serve requests from any instance.

Answer

Enable Cloud CDN for the static content.

Answer

Purchase 1-year committed use contracts for the instances.

Answer

Use preemptible VMs to reduce cost.

Question 5

Your organization is implementing a Disaster Recovery plan for a critical database. Which THREE components are essential for a robust DR strategy? (Choose 3)

Accepted Answer

Automated failover process to switch traffic to the DR region.. An automated failover process is essential for minimizing Recovery Time Objective (RTO) in a Disaster Recovery strategy. Without automation, manual intervention introduces delays and risks of human error, which can extend downtime significantly. In cloud or on-premises environments, automated failover typically relies on health checks, DNS updates, or traffic manager rules to seamlessly redirect traffic to the DR region when the primary fails.

Answer

A single global load balancer for both regions.

Answer

Using a single zone for the primary region.

Question 6

Your service has a 99.99% uptime SLO (monthly error budget ~ 4 minutes). Which TWO monitoring practices best support this SLO? (Choose 2)

Accepted Answer

Use a combination of availability (e.g., HTTP 200 rate) and latency (e.g., p99) as SLIs.. Options B and E are correct. A good SLI combines availability and latency into a single measure; the error budget approach is the standard way to manage SLOs. Option A is wrong: CPU alone is not a user-facing SLI. Option C is wrong: synthetic monitoring is useful but not alone sufficient; a combination of real and synthetic is recommended. Option D is wrong: alerting on every 5xx error can lead to alert fatigue; better to alert based on error budget burn rate.

Answer

Monitor CPU utilization and alert when average exceeds 80%.

Answer

Use only synthetic monitoring from multiple locations.

Answer

Alert on every 5xx error immediately.

Question 7

The exhibit shows the output of a 'gcloud compute instances describe' command for an instance. What is the most likely impact on reliability if the host machine needs maintenance?

Accepted Answer

The instance will be terminated and then restarted, causing a brief downtime.. When a host machine requires maintenance, Google Compute Engine instances that are not configured for live migration will be terminated and then restarted on another host. This behavior is determined by the 'onHostMaintenance' setting; if it is set to 'TERMINATE' (the default for instances with GPUs or preemptible VMs), the instance stops and restarts, causing brief downtime. The exhibit likely shows 'onHostMaintenance: TERMINATE' or the instance lacks live migration support, making termination and restart the expected outcome.

Answer

The instance will not be affected because automatic restart is enabled.

Answer

The instance will be backed up automatically before maintenance.

Answer

The instance will be live migrated to another host without interruption.

Question 8

The exhibit shows a Cloud Storage bucket configuration. What does this configuration ensure?

Accepted Answer

Objects can only be permanently deleted after the retention period expires.. The exhibit shows a bucket configured with a retention policy. When a retention policy is set on a Cloud Storage bucket, objects cannot be deleted or overwritten until the retention period expires. This ensures that objects can only be permanently deleted after the retention period ends, which is exactly what option C describes.

Answer

Older versions of objects are automatically transferred to a different storage class.

Answer

Data is replicated to another region for disaster recovery.

Answer

Objects older than 30 days will be automatically deleted.

Question 9

The exhibit shows a managed instance group configuration. What is the primary purpose of the 'autoHealingPolicies' section?

Accepted Answer

Automatically replace instances that are deemed unhealthy based on the health check.. The 'autoHealingPolicies' section in a managed instance group configuration is specifically designed to automatically replace instances that are deemed unhealthy based on a configured health check. When a health check probe (e.g., HTTP, TCP, or SSL) fails for a sustained period, the managed instance group terminates the unhealthy instance and creates a new one from the instance template, ensuring the desired number of healthy instances is maintained. This is distinct from autoscaling, which adjusts instance count based on load metrics.

Answer

Distribute incoming traffic evenly across the instances.

Answer

Automatically add more instances when CPU utilization exceeds 60%.

Answer

Automatically update instances to a new instance template.

Question 10

A company runs a global e-commerce site on GKE. They want to ensure disaster recovery with multi-region deployment. What is the best practice for configuring GKE clusters?

Accepted Answer

Deploy separate regional clusters in two or more regions.. For disaster recovery with a multi-region deployment, the best practice is to deploy separate regional clusters in two or more regions. This ensures that if an entire region fails, traffic can be redirected to the other region's cluster, providing true geographic redundancy. A single cluster, whether zonal or regional, cannot survive a regional outage because it is bound to a single control plane location.

Answer

Use a single zonal cluster with node auto-repair.

Answer

Deploy a single cluster with multi-master setup.

Answer

Use a single regional cluster with multiple zones.

Question 11

An application running on Compute Engine instances behind a load balancer experiences intermittent failures. Health checks show instances passing, but some users get errors. What should be the first troubleshooting step?

Accepted Answer

Review the application logs for errors.. The correct first step is to review the application logs (Option B) because the issue is intermittent failures despite healthy load balancer health checks. Since health checks confirm the instances are reachable and responding correctly at the health check endpoint, the problem likely lies within the application itself—such as request handling errors, timeouts, or resource contention. Application logs provide the most direct evidence of what is happening when users encounter errors, enabling targeted debugging before modifying infrastructure.

Answer

Increase instance size.

Answer

Enable HTTP health checks.

Answer

Check the load balancer's backend service configuration for session affinity.

Question 12

A company uses Cloud SQL for PostgreSQL. They want to minimize downtime during maintenance. Which feature should they enable?

Accepted Answer

High availability with a standby in another zone.. High availability (HA) with a standby in another zone ensures that Cloud SQL for PostgreSQL automatically fails over to a standby instance in a different zone if the primary zone experiences an outage. This minimizes downtime during maintenance because Cloud SQL performs a controlled failover to the standby, typically completing within a few seconds, rather than requiring a full instance restart or rebuild.

Answer

Read replicas.

Answer

Point-in-time recovery.

Answer

Automated backups.

Question 13

A company has a microservices architecture on GKE. One service is failing due to resource exhaustion. How can they proactively prevent this?

Accepted Answer

Configure a horizontal pod autoscaler with custom metrics.. A horizontal pod autoscaler with custom metrics (e.g., memory, request queue depth) can detect resource exhaustion early and scale pods before failure. Option A (vertical pod autoscaling) may not react fast enough or may not scale horizontally, which is needed for stateless microservices. Option B (CPU-based autoscaling) may not capture all types of resource exhaustion (e.g., memory leaks). Option D (cluster autoscaler) scales nodes, not pods, so it does not directly address pod-level resource exhaustion.

Answer

Use vertical pod autoscaling.

Answer

Set up autoscaling based on CPU utilization.

Answer

Implement a cluster autoscaler.

Question 14

A company wants to monitor their Cloud Run services for errors and latency. Which Google Cloud product should they use?

Accepted Answer

Cloud Monitoring. Cloud Monitoring (formerly Stackdriver Monitoring) provides comprehensive observability for Cloud Run services, including built-in dashboards for request latency, error rates, and resource utilization. It collects metrics like request count, request latencies, and container instance counts, and allows you to set alerting policies based on these metrics. While Cloud Trace can help with latency analysis and Cloud Logging captures logs, Cloud Monitoring is the primary product for monitoring both errors and latency in a unified view.

Answer

Cloud Trace

Answer

Cloud Logging

Answer

Error Reporting

Question 15

An organization needs to meet a RTO of 1 hour for a critical application running on GCE with persistent disks. What is the most cost-effective approach?

Accepted Answer

Use regional persistent disks.. Regional persistent disks (PD) provide synchronous replication of data between two zones in the same region, enabling automatic failover for a GCE instance without manual intervention. This meets the 1-hour RTO by allowing the instance to be recreated or failed over to the secondary zone quickly, and it is more cost-effective than maintaining a full replica instance because you only pay for the disk storage and replication, not for an idle compute instance.

Answer

Replica of compute instance in another zone.

Answer

Frequent disk image exports.

Answer

Regular snapshots to a regional bucket.