PCDOE Practice Test 3 — 30 Questions

Question 1

Refer to the exhibit. A DevOps engineer observes that a GKE cluster's node performance is degraded during high I/O workloads. Based on the exhibit, which change would most likely improve disk I/O performance?

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

Accepted Answer

Change diskType to pd-ssd. The exhibit shows a GKE node pool using the default pd-standard disk type, which is backed by HDDs and has lower IOPS and throughput compared to SSDs. Changing diskType to pd-ssd directly improves disk I/O performance by providing higher IOPS and lower latency, which is critical for high I/O workloads.

Answer

Change machineType to n2-standard-4

Answer

Change imageType to UBUNTU

Answer

Change serviceAccount to a custom one

Question 2

Which TWO practices are recommended for implementing CI/CD pipelines on Google Cloud?

Accepted Answer

Use a Dockerfile to define the build process for containerized applications.. Option D is correct because using a Dockerfile to define the build process is the standard, reproducible way to build containerized applications in a CI/CD pipeline, and Cloud Build natively supports Dockerfile-based builds (e.g., via the docker builder or `gcloud builds submit`), ensuring consistent images across environments. Option E is correct because Cloud Build substitutions (user-defined variables like `${_ENV}` or built-in ones like `$PROJECT_ID`) let you parameterize a single build configuration (cloudbuild.yaml) so the same pipeline can target dev, staging, and prod with different values, avoiding duplicated configs. Option A is wrong because storing service account keys in the build configuration file exposes long-lived credentials in source control; the recommended practice is Workload Identity Federation or attaching a user-managed service account to the build, not embedding keys. Option B is wrong because deploying straight to production after a successful build skips approval gates and progressive delivery, which is not a recommended CI/CD practice for production safety. Option C is wrong because a single monolithic pipeline for all microservices reduces isolation and blast radius control; per-service pipelines (or at least independent triggers) are recommended so services can build, test, and deploy independently.

Answer

Store service account keys in the build configuration file for authentication.

Answer

Deploy to production directly after a successful build without any approval gate.

Answer

Create a single build pipeline that handles all microservices to reduce complexity.

Question 3

A DevOps team is setting up a CI/CD pipeline using Cloud Build. They want the Cloud Build service account to have permission to deploy to Cloud Run within a specific project. Which IAM role should be granted to the Cloud Build service account?

Accepted Answer

roles/run.admin. The Cloud Build service account needs the `roles/run.admin` role to deploy services to Cloud Run. This role grants full control over Cloud Run resources, including creating, updating, and deleting services, which is required for a CI/CD pipeline to perform deployments. Without this role, the service account would lack the necessary permissions to modify Cloud Run configurations.

Answer

roles/run.invoker

Answer

roles/cloudbuild.builds.editor

Answer

roles/iam.serviceAccountUser

Question 4

A startup is bootstrapping a Google Cloud organization for DevOps. They need to create a project for their CI/CD tooling and a separate project for logging and monitoring. What is the recommended way to structure the resource hierarchy?

Accepted Answer

Create a folder called 'DevOps' and place both projects inside it, sharing a billing account.. The recommended Google Cloud resource hierarchy for DevOps bootstrapping is to create a folder (e.g., 'DevOps') under the organization node and place both projects inside it. This structure allows centralized policy inheritance (e.g., IAM, org policies) and shared billing via a single billing account, while maintaining logical separation between CI/CD and logging/monitoring workloads. It aligns with Google's best practices for multi-project isolation without unnecessary organizational complexity.

Answer

Create a single project for all workloads and use labels to differentiate environments.

Answer

Create both projects directly under the organization node, with separate billing accounts.

Answer

Create a separate organization for each project to ensure isolation.

Question 5

A team uses Cloud Load Balancing with backend NEGs. Users report intermittent high latency. How should they diagnose the root cause effectively?

Accepted Answer

Use Cloud Trace to analyze per-request latency spans. Cloud Trace provides end-to-end latency analysis by capturing per-request spans as they traverse the load balancer, backend NEGs, and other services. This allows you to pinpoint exactly which hop (e.g., load balancer processing, backend queuing, or application code) is causing the intermittent high latency, rather than relying on aggregate metrics or caching assumptions.

Answer

Increase the number of backend instances immediately

Answer

Enable Cloud Monitoring latency histogram for the load balancer

Answer

Check Cloud CDN cache hit ratio

Question 6

An application running on App Engine standard environment has high instance startup latency, leading to slow first requests. What is the most effective configuration change to reduce cold starts?

Accepted Answer

Set min_idle_instances to a value greater than 0. Setting min_idle_instances to a value greater than 0 ensures that a baseline number of instances are always running and ready to serve requests, eliminating the need to spin up new instances on the first request. This directly reduces cold start latency because the application does not have to wait for instance initialization, which includes loading dependencies and running startup scripts.

Answer

Use manual scaling instead of automatic scaling

Answer

Use Cloud Endpoints for request authentication

Answer

Increase the memory limit per instance

Question 7

A team deploys a microservice on Google Kubernetes Engine (GKE) that processes user uploads. The service latency has increased over time. Monitoring shows that CPU utilization is low, but memory usage is high and garbage collection (GC) pauses are frequent. Which action is most likely to reduce latency?

Accepted Answer

Increase the memory limit and requests for the container.. Frequent GC pauses and high memory usage with low CPU indicate the JVM heap is too small, causing the garbage collector to run more often. Increasing the memory limit and requests gives the JVM more headroom to reduce GC frequency, directly lowering latency. This is a classic JVM tuning scenario in containerized environments like GKE.

Answer

Scale out the deployment by increasing the number of replicas.

Answer

Reduce the number of replicas to concentrate load.

Answer

Increase the CPU limit to allow faster processing.

Question 8

A company has a steady-state workload of 100 vCPUs running 24/7. They want to get the maximum discount possible without long-term commitment. What discount should they expect?

Accepted Answer

Sustained use discount of up to 30%. The correct answer is C: Sustained use discount of up to 30%. For steady-state workloads that run continuously, Google Compute Engine automatically applies sustained use discounts, and the maximum discount for instances running the full month is 30% (for N1 machine types). Because the company wants maximum discount without any long-term commitment, this automatic discount is exactly what they should expect. Option A is wrong because committed use discounts require a 1- or 3-year commitment, which the company explicitly wants to avoid. Option B is incorrect because the sustained use discount maximum is 30%, not 20%. Option D is wrong because sustained use discounts apply automatically to eligible steady-state usage.

Answer

Committed use discount of up to 57%

Answer

Sustained use discount of up to 20%

Answer

No discount available

Question 9

Which storage class provides the lowest cost for data accessed less than once a year?

Accepted Answer

Archive. Archive storage class is the correct answer because it is specifically designed for long-term data retention where access is extremely infrequent, such as less than once a year. It offers the lowest storage cost among Google Cloud Storage classes, but with higher retrieval costs and a minimum storage duration of 365 days, making it ideal for data that is rarely accessed.

Answer

Nearline

Answer

Standard

Answer

Coldline

Question 10

Which Google Cloud service provides a fully managed, private Git repository that integrates with Cloud Build for continuous integration?

Accepted Answer

Cloud Source Repositories. Cloud Source Repositories is the correct answer because it provides fully managed, private Git repositories hosted on Google Cloud. It integrates natively with Cloud Build, enabling automatic triggers for continuous integration (CI) pipelines whenever code is pushed to a repository branch or tag, without requiring external Git hosting.

Answer

Cloud Deployment Manager

Answer

Cloud Storage

Answer

Container Registry

Question 11

After deploying a new version of a Cloud Run service, the team notices an increase in 5xx errors. They want to quickly revert to the previous version while minimizing user impact. What is the recommended approach?

Accepted Answer

Use Cloud Run's traffic management to set 100% of traffic to the previous revision.. Cloud Run supports traffic splitting between revisions, allowing you to instantly route 100% of traffic to the previous revision without redeploying. This minimizes user impact because the rollback is immediate and does not require rebuilding or re-pulling container images. Option D is correct because it leverages Cloud Run's built-in traffic management feature for zero-downtime rollbacks.

Answer

Set the minimum number of instances of the new revision to 0.

Answer

Redeploy the previous version from the container registry.

Answer

Modify the ingress settings to restrict traffic to the new revision.

Question 12

Refer to the exhibit. A DevOps engineer observes that a GKE cluster's node performance is degraded during high I/O workloads. Based on the exhibit, which change would most likely improve disk I/O performance?

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

Accepted Answer

Stop instance-1 and update the minimum CPU platform to Skylake.. Stopping the instance and updating the minimum CPU platform to Skylake ensures that the instance is rescheduled onto a host that meets the required CPU feature set. This action directly addresses the application's sensitivity to CPU features available only on Skylake or newer, without requiring a full recreation or risking compatibility issues during live migration.

Answer

Live migrate instance-1 to a different host.

Answer

Use Terraform to add a lifecycle rule to ignore changes.

Answer

Terminate instance-1 and recreate it with a newer machine type.

Question 13

A DevOps team is setting up SLOs for a service with two critical metrics: availability and latency. They want to measure over a 30-day window. Which approach correctly defines an SLO?

Accepted Answer

Use Cloud Monitoring to create a custom SLI based on request latency metrics and set an SLO with a 30-day rolling window. It uses Cloud Monitoring to create a custom SLI based on request latency metrics, which is a valid SLI type, and sets an SLO with a 30-day rolling window, matching the requirement. Cloud Monitoring's SLO feature natively supports rolling windows, and latency is a standard metric for defining service-level objectives.

Answer

Use Cloud Monitoring to create a custom SLI based on logs and set an SLO with a 7-day rolling window

Answer

Use Cloud Tasks to schedule a cron job that calculates availability

Answer

Use Stackdriver Monitoring (deprecated) to set an SLO with a fixed 30-day window

Question 14

Refer to the exhibit. The output shows a recommendation from the Cloud Cost Optimization recommender for an instance in us-central1-a. The instance is a production web server that consistently runs at 25% CPU utilization during peak hours. What should the DevOps engineer do to implement this recommendation with minimal risk?

Accepted Answer

Stop the instance, change the machine type to n2-standard-4, and start it again.. The Cloud Cost Optimization recommender has identified that the current instance is over-provisioned for its actual workload (25% CPU utilization during peak hours). By stopping the instance, changing the machine type to n2-standard-4 (which has 4 vCPUs and 16 GB RAM, matching the recommended 4 vCPUs and 15 GB memory), and starting it again, the engineer rightsizes the instance without incurring downtime during the change itself. This approach minimizes risk because the instance is stopped only briefly for the machine type change, and the new machine type is a standard, well-tested configuration that aligns with the recommender's analysis.

Answer

Ignore the recommendation because the instance is production and any change might cause downtime.

Answer

Add a second n2-standard-4 instance behind a load balancer to distribute load.

Answer

Use a custom machine type with 4 vCPUs and 32 GB memory to ensure enough RAM.

Question 15

A DevOps team is using Cloud Build to build and push container images. The build times have increased significantly. They suspect that the build cache is not being used effectively. Which build configuration change would likely improve cache usage?

Accepted Answer

Use kaniko instead of Docker. Kaniko is a cache-aware container image builder that can leverage a remote image registry as a cache layer, unlike the default Docker builder which relies on a local Docker daemon and its local layer cache. By using Kaniko with a configured cache repository, the team can reuse previously built layers across builds, even when builds run on different Cloud Build workers, significantly reducing build times.

Answer

Increase the machine type

Answer

Use a private pool

Answer

Enable parallel builds

Question 16

Which TWO are best practices for implementing CI/CD on Google Cloud?

Accepted Answer

Use Artifact Registry for storing container images.. Artifact Registry is the recommended service for storing, managing, and securing container images and other artifacts in Google Cloud. It integrates natively with Cloud Build, Cloud Run, and Kubernetes, providing vulnerability scanning and IAM-based access control, which are essential for a secure CI/CD pipeline.

Answer

Use Cloud Run for all services.

Answer

Use Cloud Build for all deployments, including infrastructure changes.

Answer

Use GitHub Actions instead of Cloud Build.

Question 17

Refer to the exhibit. You are reviewing an alert policy for CPU utilization. What is a potential problem with this configuration?

Accepted Answer

The duration is too short, which may cause noise during spikes.. A short duration in a CPU utilization alert policy means the threshold must be breached for only a brief period before triggering an incident. This can cause noise during transient spikes that are not indicative of a sustained problem, leading to false positives and alert fatigue for operations teams.

Answer

The autoClose time is too long.

Answer

The threshold is set too low.

Answer

The combiner should be 'AND'.

Question 18

Which TWO are benefits of using Cloud Build triggers to implement CI/CD pipelines?

Accepted Answer

Start a build automatically when changes are pushed to a repository. Cloud Build triggers can be configured to automatically start a build in response to events such as a push to a repository branch or the creation of a pull request. This event-driven automation is the foundation of a CI/CD pipeline, eliminating the need for manual build initiation and ensuring that every code change is validated immediately.

Answer

Deploy to a specific Google Cloud region based on the trigger

Answer

Support only a single branch per trigger

Answer

Automatically provision infrastructure as part of the build

Question 19

A team uses Cloud Monitoring alerting policies with multiple conditions. They want an incident to fire only when both conditions are met simultaneously. What should they configure?

Accepted Answer

Set the alerting policy combiner to 'AND'. Cloud Monitoring alerting policies support a 'combiner' field that can be set to 'AND' to require that all conditions are met simultaneously before the incident fires. This ensures the alert triggers only when both conditions are true at the same evaluation window, rather than when either condition is met.

Answer

Create two separate alerting policies

Answer

Create a single condition with a ratio metric

Answer

Use a log-based metric condition

Question 20

Arrange the steps to implement a canary deployment for a Cloud Run service.

Accepted Answer

Deploy new revision with 0% traffic, then shift a small percentage of traffic to it, then monitor, then gradually increase traffic, then remove old revision.. In a canary deployment for Cloud Run, the correct sequence ensures minimal risk. First, deploy the new revision with 0% traffic. Then, route a small percentage (e.g., 1%) to it and monitor for errors or performance issues. If successful, gradually increase traffic while monitoring. Once the new revision is fully validated, point 100% traffic to it and remove the old revision. This incremental approach limits blast radius and allows rollback.

Answer

Shift a small percentage of traffic to the new revision, then deploy the new revision, then monitor, then gradually increase traffic, then remove old revision.

Answer

Deploy new revision with 0% traffic, then gradually increase traffic to 100%, then monitor, then remove old revision.

Answer

Deploy new revision with 0% traffic, then shift a small percentage of traffic, then remove old revision, then monitor, then gradually increase traffic.