PCDOE Practice Test 29 — 15 Questions

Question 1

A team implements canary deployments using Cloud Deploy and deploys to GKE. They want to automatically roll back if the canary release's error rate exceeds 5% within 10 minutes. Which approach should they use?

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

Accepted Answer

Set up Cloud Deploy with a rollout strategy that uses Cloud Monitoring metrics to automatically rollback.. Cloud Deploy can leverage Cloud Monitoring metrics as part of a rollout strategy to automatically roll back a canary deployment when the error rate exceeds a defined threshold (e.g., 5% within 10 minutes). Options A is incorrect because Spinnaker is not native to GCP and does not integrate seamlessly with Cloud Deploy; also Spinnaker is not the recommended tool for this scenario. Option B is incorrect because Cloud Build is intended for building and testing artifacts, not for real-time monitoring and rollback of deployments. Option C is incorrect because a rolling update strategy does not support canary deployments or metric-based automatic rollback; it simply replaces pods gradually.

Answer

Deploy using Spinnaker on GKE with a canary pipeline that includes an automated rollback step.

Answer

Configure a Cloud Build step to monitor the canary and rollback if needed.

Answer

Use a GKE rolling update strategy within the deployment manifest.

Question 2

Refer to the exhibit. A rollout to dev succeeds, but when promoting to prod, it fails with 'Target 'prod' not found'. What is the issue?

Accepted Answer

The prod target has not been created in the same region.. The error 'Target 'prod' not found' indicates that the prod target does not exist in the Cloud Deploy pipeline. In Google Cloud Deploy, targets must be created in the same region as the delivery pipeline to be referenced. If the prod target was not created in the same region as the pipeline, it will not be found during promotion.

Answer

The prod target does not have a required approval rule.

Answer

The prod target exists but is in a different project.

Answer

The delivery pipeline must be redeployed to include the prod target.

Question 3

A development team is using Cloud Build to build and push Docker images to Artifact Registry. The builds are taking longer than expected, and the team wants to reduce build time and cost. They use a Dockerfile that installs many dependencies. Which approach should they recommend?

Accepted Answer

Use Kaniko cache in Cloud Build with a persistent volume claim to cache base layers.. Using Kaniko with a persistent volume claim allows caching of base layers across builds, significantly reducing build time by reusing previously downloaded layers. Option A increases cost by using more resources without addressing caching inefficiency. Option C uses Docker with privileged mode, which is slower and less secure than Kaniko. Option D reduces parallelism by consolidating steps, which can increase build time rather than reduce it.

Answer

Increase the machine type to use more vCPUs and memory for the build.

Answer

Switch to Docker build with --privileged flag and use a local Docker daemon.

Answer

Reduce the number of steps in the Cloud Build config to a single step that installs and builds everything.

Question 4

An organization wants to optimize BigQuery costs. Which three practices should they implement? (Choose three.)

Accepted Answer

Set a maximum bytes billed per query at the project level. Options B, C, and E are correct. Setting a maximum bytes billed per query at the project level prevents cost overruns. Table partitioning and clustering reduce the amount of data scanned per query, lowering costs. Authorized views allow controlled access without duplicating data, avoiding storage costs. Option A is incorrect because storing data in multiple tables without partitioning increases data scanned and costs. Option D is incorrect because purchasing flat-rate reservations for all queries may not be cost-effective for variable workloads; on-demand pricing can be cheaper.

Answer

Store data in multiple tables per day without partitioning

Answer

Purchase BigQuery flat-rate reservations for all queries

Question 5

Refer to the exhibit. The company received an alert when the threshold was triggered. What does this alert indicate?

Accepted Answer

The actual spend has reached 50% of the budget.. The threshold rule uses a CURRENT_SPEND basis, so the alert triggers when actual costs reach 50% of the budget. This corresponds to Option A. Option B describes exceeding the budget, Option C describes a forecasted exceedance, and Option D describes both thresholds, none of which are indicated by this alert.

Answer

The spend has exceeded the budget amount.

Answer

The forecasted spend is projected to exceed 50% of the budget.

Answer

Both actual and forecasted spend thresholds have been crossed.

Question 6

Refer to the exhibit. A DevOps engineer configured a budget alert with Pub/Sub notifications. However, the team is not receiving alerts. The Pub/Sub subscription is set up correctly and messages can be published manually. What is the most likely reason the budget alerts are not being sent?

Accepted Answer

The budget filter excludes credits, so actual spend might be lower than threshold. The budget filter excludes credits. If credits significantly reduce actual spend, the threshold might not be met, and alerts may not fire. Option A is incorrect because the notificationsRule can be configured without email recipients if Pub/Sub is used. Option B is incorrect because budget amounts are specified in whole units; fractional cents are not relevant. Option C is incorrect because using different spend bases (CURRENT vs FORECASTED) is allowed and does not cause inconsistency in alerting.

Answer

The notificationsRule does not include email recipients

Answer

The budget amount is specified in units without considering fractional cents

Answer

The threshold rules use different spend basis (CURRENT vs FORECASTED), causing inconsistency

Question 7

You are the DevOps engineer for a social media platform. After a recent code rollout, you receive multiple user complaints about failed logins. The service logs show a sharp increase in 5xx errors from the authentication service. However, the existing alerting policy for the authentication service did not fire. The policy is configured to trigger if the error rate exceeds 5% for 5 minutes. Upon checking Cloud Monitoring, you see that the error rate spiked to 15% for 3 minutes, then dropped back to normal. What is the most likely reason the alert did not fire?

Accepted Answer

The duration condition of 5 minutes was not satisfied.. The alert did not fire because the policy requires the error rate to exceed 5% for a continuous duration of 5 minutes. The spike only lasted 3 minutes, which is shorter than the configured duration condition, so the alerting policy's condition was never fully met. In Google Cloud Monitoring, alerting policies evaluate both the threshold and the duration window before transitioning to a firing state.

Answer

The error rate threshold of 5% was too low, causing the alert to be suppressed.

Answer

The alignment period for the metric was set to 5 minutes, hiding the spike.

Answer

The notification channel was incorrectly configured.

Question 8

A DevOps engineer notices that the budget alerts for a project are not triggering even though spending exceeds thresholds. The budget is configured at the billing account level, filtering for that project only. The project is linked to the correct billing account. What is the most likely cause?

Accepted Answer

The budget notifications are only sent to Pub/Sub, and no subscriber is active. Budget notifications are configured to be sent to a Pub/Sub topic when spending exceeds thresholds. If there is no active subscription on that topic, the messages are not consumed, and therefore no alerts are triggered or delivered. Option A is unlikely because the budget filter excluding credit types does not prevent alerting; it simply means credits are not considered in the spend calculation. Option B is incorrect because Google Cloud budgets are set in actual currency units, not in units of 1000. Option D is incorrect because including services that are not used does not affect the alert threshold; it simply means those services have zero spend.

Answer

The budget filter excludes credit types, and the spending includes credits that reduce the effective spend below threshold

Answer

The budget amount is set in units of 1000, so $5000 is actually 5 units, causing confusion

Answer

The budget filter includes services that are not used in the project

Question 9

A company uses BigQuery for analytics. They notice high costs due to queries scanning large amounts of data. They want to reduce costs without sacrificing performance for urgent queries. Which approach is most cost-effective?

Accepted Answer

Partition and cluster tables, and use BI Engine for acceleration. B is correct because partitioning and clustering reduce the amount of data scanned per query, and BI Engine accelerates query performance, reducing cost without sacrificing speed for urgent queries. A is wrong: flat-rate pricing does not reduce data scanned; it's a pricing model that can be wasteful if not fully utilized. C is wrong: query caching only returns cached results for repeated queries, but doesn't reduce data scanned for new queries. D is wrong: materialized views precompute results but incur storage costs and are not suitable for all ad-hoc queries; limiting to interactive priority doesn't reduce scanned data as effectively as partitioning/clustering.

Answer

Use flat-rate pricing with reservations

Answer

Use on-demand pricing with query caching

Answer

Use materialized views and limit query jobs to interactive priority

Question 10

A Cloud Run service experiences high cold start latency. The team has already set min-instances to 1. Which additional optimization can further reduce cold start impact?

Accepted Answer

Reduce container image size and enable CPU boost during startup. Reducing the container image size decreases the time required to pull and unpack the container on a cold start, and enabling CPU boost during startup temporarily allocates additional CPU resources to accelerate the initialization process. Together, these directly address the root causes of cold start latency by minimizing both the image loading time and the application initialization time, even when min-instances is already set to 1.

Answer

Use HTTP/2 to speed up request handling

Answer

Place the service on Cloud Run for Anthos on GKE

Answer

Increase the container memory limit

Question 11

A service experiences increased latency and HTTP 503 errors. The engineer finds that the backend managed instance group (MIG) is at max instances and CPU utilization is 90%. Which TWO actions should the engineer take to restore the service quickly?

Accepted Answer

Enable autoscaling based on HTTP load balancing utilization. Enabling autoscaling based on HTTP load balancing utilization allows the MIG to scale out based on the actual request load, which directly addresses the 503 errors caused by the backend being at max capacity. This metric is more responsive to traffic spikes than CPU utilization alone, as it reflects the frontend load balancer's view of backend capacity.

Answer

Increase the autoscaling target CPU utilization to 95%

Answer

Reduce the autoscaling target CPU utilization to 50%

Answer

Reduce the number of instances to avoid resource contention

Question 12

Refer to the exhibit. The team wants to reduce the service's p50 latency from 2 seconds to under 500ms. Which optimization would have the most impact?

Accepted Answer

Optimize getCustomerData() by caching customer data. The exhibit shows that getCustomerData() is the most time-consuming operation, taking 1.2 seconds out of the total 2-second p50 latency. Caching customer data eliminates repeated expensive lookups (e.g., database queries or external API calls), directly reducing the critical path latency. This optimization targets the largest bottleneck, making it the most impactful for achieving sub-500ms p50.

Answer

Increase the number of service instances

Answer

Optimize processOrder() by reducing logging

Answer

Optimize saveToDatabase() by using batch writes

Question 13

A DevOps engineer needs to assign IAM roles at the organization level. Which built-in role is specifically designed for managing IAM policies across the organization?

Accepted Answer

roles/iam.securityAdmin. The role `roles/iam.securityAdmin` is the built-in IAM role specifically designed for managing IAM policies across the organization. It grants permissions to get and set IAM policies at the organization, folder, and project levels, without granting other resource management permissions. This makes it the correct choice for a DevOps engineer who needs to assign IAM roles organization-wide.

Answer

roles/resourcemanager.organizationAdmin

Answer

roles/owner

Answer

roles/editor

Question 14

A company uses Cloud Deploy for continuous delivery to GKE. They have a delivery pipeline with a rollout strategy: canary (25% for 30m) then full. The canary rollout fails because the new revision's health check errors. The team wants to automatically rollback the canary and notify. What native GCP feature can achieve this?

Accepted Answer

Configure a Cloud Deploy rollout strategy with an automated rollback policy.. Cloud Deploy supports automated rollback through its rollbackPolicy configuration in the delivery pipeline. When a rollout fails health checks, the rollbackPolicy can automatically initiate a rollback to the previous successful revision. Additionally, Cloud Deploy can integrate with Cloud Monitoring or Pub/Sub to send notifications. Option A is incorrect because while you can set up an alert and Cloud Function, that is not a native feature of Cloud Deploy and requires custom implementation. Option B is incorrect because Cloud Build triggers are meant for building and testing, not for rollback automation. Option D is incorrect because post-deploy hooks are for custom actions after deployment, not for automatic rollback on failure.

Answer

Configure Cloud Monitoring alerting policy on deployment errors that triggers a Cloud Function to rollback.

Answer

Set up a Cloud Build trigger that detects deployment failure and runs a rollback.

Answer

Use a Cloud Deploy rollout strategy with a post-deploy hook that calls Cloud Run jobs to revert.

Question 15

A government agency is bootstrapping a Google Cloud organization with strict compliance requirements. They must: (1) store all logs in a centralized project with retention of 7 years, (2) ensure no data leaves the United States, (3) use customer-managed encryption keys (CMEK) for all persistent disks and buckets, (4) automatically reject any resource creation outside allowed regions (us-central1 and us-east1). They have an existing on-premises SIEM that needs to receive logs via Pub/Sub. The network team wants to use Shared VPC. What is the correct order of steps to implement this?

Accepted Answer

Create folder hierarchy, set org policies for allowed regions and CMEK, configure aggregated log sink to centralized project, set up Shared VPC, and create Pub/Sub topic for SIEM.. It follows the recommended Google Cloud landing zone bootstrap order: first establish the folder hierarchy to apply organization policies (like constraints/compute.restrictResourceCreation and constraints/gcp.resourceLocations) and CMEK requirements at the correct level, then create the aggregated log sink to the centralized project with a 7-year retention bucket, set up Shared VPC for network isolation, and finally create the Pub/Sub topic for the SIEM. This sequence ensures that policies are inherited before resources are created, preventing non-compliant resource creation and ensuring logs are captured from the start.

Answer

Set up Pub/Sub for SIEM first, then create log sink, then apply org policies.

Answer

Create all projects first, then move them into folders, then apply org policies.

Answer

Create Shared VPC first, then set up org policies, then create log sink, then create folders.