PCD Practice Test 23 — 15 Questions

Question 1

An e-commerce company relies on a Compute Engine backend serving content to global users. They notice high latency for users outside the primary region. Which service should they add to reduce latency by caching content at edge locations?

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

Accepted Answer

Cloud CDN. Cloud CDN (Content Delivery Network) uses Google's global edge cache locations to serve cached content closer to users, reducing latency for requests that would otherwise travel to the origin Compute Engine backend in a single region. By caching static or dynamic content at edge nodes, Cloud CDN minimizes round-trip time and offloads traffic from the backend instance.

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Cloud Armor

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Cloud NAT

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Cloud Endpoints

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Cloud Load Balancing

Question 2

A developer is writing integration tests for a Cloud Function that uses Cloud Firestore. The tests must run in a local environment without incurring costs or affecting production data. What should the developer use?

Accepted Answer

Use the Firestore emulator running locally.. The Firestore emulator, part of the Firebase Local Emulator Suite, allows integration tests to run entirely on the local machine without network calls to GCP. This avoids incurring costs and prevents any impact on production data, as all operations are performed against an in-memory Firestore instance that mimics the real service's behavior.

Answer

Create a separate GCP project for testing and use its Firestore.

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Mock the Firestore client library calls.

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Run tests against the production Firestore instance with a test prefix.

Question 3

Your company runs a production App Engine standard environment service (module 'frontend', version 'v2') that handles e-commerce checkout requests. You have set up an alerting policy on a custom metric 'request_latency' that fires when latency exceeds 500ms for 1 minute. Recently, customers have complained about slow checkout times, but no alert has fired. You examine the exhibit: the log entry shows a latency of 0.452s (452ms) for a request to '/api/checkout'. The custom metric is defined from OpenTelemetry instrumentation. What is the most likely reason the alert did not fire?

Accepted Answer

The alert threshold is 500ms, and the exhibited request latency is 452ms, which is below the threshold. Individual requests may be below the threshold, so the alert does not fire.. The alerting policy is configured to fire when the custom metric 'request_latency' exceeds 500ms for 1 minute. The exhibited log entry shows a latency of 452ms, which is below the 500ms threshold. The alert condition is based on a metric threshold, not individual log entries, and since the metric value remains below the threshold, the alert does not trigger.

Answer

The alert condition uses a threshold on a metric that is not being written because the OpenTelemetry exporter is not configured for the 'frontend' module.

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The log entry does not contain the required custom metric data because the httpRequest field is not parsed by Cloud Monitoring.

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The custom metric is only emitted for version 'v1', and the current version is 'v2', so no metric data is available for the alert.

Question 4

A company uses Cloud Logging to store application logs. They need to keep logs for 3 years for compliance. What is the most cost-effective way to store logs for this duration?

Accepted Answer

Create a sink to export logs to Cloud Storage with object lifecycle rules. Cloud Logging's default retention is limited (e.g., 30 days for logs, with some exceptions up to 400 days), so it cannot meet a 3-year compliance requirement. Exporting logs to Cloud Storage and applying object lifecycle rules allows you to automatically transition objects to lower-cost storage classes (e.g., from Standard to Nearline, Coldline, or Archive) and delete them after the retention period, minimizing cost while meeting the 3-year retention need.

Answer

Use Cloud Logging's default retention

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Create a sink to export logs to Pub/Sub

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Create a sink to export logs to BigQuery

Question 5

A company has a legacy monolithic application running on Compute Engine that is being migrated to microservices on GKE. During the migration, they need to maintain performance monitoring across both environments. The legacy application uses Stackdriver Logging and Monitoring agents (now Ops Agent) and exports logs to Cloud Logging. The new microservices are instrumented with OpenTelemetry for traces and metrics. The team wants a unified view of performance across both environments, including distributed traces from the new services and log-based metrics from the legacy app. They also want to correlate logs and traces for troubleshooting. Which solution should they implement?

Accepted Answer

Use Cloud Monitoring dashboards and ingest OpenTelemetry metrics into Cloud Monitoring, while using Cloud Logging log-based metrics from legacy app.. It provides a unified view by ingesting OpenTelemetry metrics into Cloud Monitoring and using Cloud Logging log-based metrics from the legacy app. Cloud Monitoring supports OpenTelemetry metrics via the OpenTelemetry Protocol (OTLP) and can correlate them with log-based metrics from the legacy app, enabling distributed tracing and log correlation in a single dashboard.

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Keep monitoring separate and use separate dashboards for legacy and new.

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Use a third-party APM tool that supports both environments.

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Rewrite the legacy app to use OpenTelemetry.

Question 6

A company is using Cloud Bigtable for real-time analytics. They want to ensure high availability and the ability to perform maintenance without downtime. They also want to reduce read latency for users in Asia. Which TWO actions should they take?

Accepted Answer

Add a secondary cluster in an Asian region.. Adding a secondary cluster in an Asian region provides regional redundancy (HA) and reduces read latency for Asian users. Application profile routing sends reads to the nearest cluster. Adding nodes to the existing cluster improves throughput but not HA or latency in Asia. HDD storage is slower. Multi-region is not a Bigtable concept.

Answer

Switch to HDD storage to reduce costs.

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Increase the number of nodes in the existing cluster.

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Convert to a multi-region instance.

Question 7

Which TWO are benefits of using Cloud Build? (Choose two.)

Accepted Answer

It allows using custom build steps with community or private images. Cloud Build allows you to use custom build steps with community or private container images, enabling you to run arbitrary tools and scripts as part of your build pipeline. This flexibility means you are not limited to Google-provided build steps and can integrate any software that runs in a container.

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It only supports Java and Go runtimes

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It requires a trigger to start any build

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It provides a source code repository for version control

Question 8

A team is using Firestore for a mobile application. They need to write security rules that allow users to read and write only their own documents. The documents have a field 'ownerId' that matches the user's UID. Which THREE rule components should they use? (Choose 3.)

Accepted Answer

Use resource.data to access the document's fields.. The three core components for Firestore security rules that allow users to read/write only their own documents are: (A) resource.data to access document fields, (B) request.resource to validate incoming write data, and (E) request.auth to verify the user's identity. Option C is a complete rule that combines A and E, not a separate component. Option D is incorrect because exists() checks document existence, not field matching.

Answer

Write a rule that allows read if request.auth.uid == resource.data.ownerId.

Answer

Use the exists() function to check if the ownerId field exists.

Question 9

Which TWO are benefits of using Cloud Build for your CI/CD pipeline?

Accepted Answer

Built-in integration with Cloud Source Repositories, GitHub, and Bitbucket.. Cloud Build natively integrates with Cloud Source Repositories, GitHub, and Bitbucket, allowing you to automatically trigger builds on code commits without additional configuration. This tight integration streamlines the CI/CD pipeline by eliminating the need for external webhook management or custom connectors.

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Provides unlimited free build minutes per day.

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Supports only Java and Python.

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Requires manual setup for all test runners.

Question 10

Drag and drop the steps to troubleshoot a failed Cloud Build in the correct order.

Accepted Answer

Check Cloud Build logs first, then examine build configuration, then fix identified issues, then re-run the build.. Troubleshooting involves reviewing logs and configuration, then fixing and re-running.

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Re-run the build first, then check logs, then examine configuration, then fix issues.

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Examine build configuration first, then re-run the build, then check logs, then fix issues.

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Fix issues first, then check logs, then examine configuration, then re-run.

Question 11

Drag and drop the steps to set up a Firestore database in native mode in the correct order.

Accepted Answer

Enable Firestore API, then Create Firestore database in native mode, then Add data to the database. Firestore native mode is selected during database creation, then data can be added.

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Create Firestore database in native mode, then Enable Firestore API, then Add data to the database

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Enable Firestore API, then Add data to the database, then Create Firestore database in native mode

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Create Firestore database in native mode, then Add data to the database, then Enable Firestore API

Question 12

A company serves static content (images, CSS) through a Cloud Load Balancer with Cloud CDN enabled. They release a new version of the website with updated image assets. After deployment, users still see old images, even though the new image files are served from the backend. The team has already invalidated the cache for the directory containing the images using the Cloud CDN invalidation feature with a specific path. However, the old images persist. What is the most effective additional step to ensure users see the new images?

Accepted Answer

Use a wildcard in the Cloud CDN invalidation path (e.g., /images/*).. Cloud CDN cache invalidation requires exact path matching unless a wildcard is used. The team invalidated a specific path but likely missed the exact paths of the cached image files. Using a wildcard like `/images/*` ensures all objects under the `/images/` directory are invalidated, forcing the CDN to fetch the updated images from the backend.

Answer

Set the cache TTL for the image directory to 0 seconds.

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Change the load balancer cache mode to 'FORCE_CACHE_ALL'.

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Configure cache key parameters to ignore query strings.

Question 13

A financial services company needs a globally distributed, strongly consistent database that can handle OLTP workloads with high throughput and automatic scaling. Which Google Cloud database should they use?

Accepted Answer

Cloud Spanner. Cloud Spanner is the only Google Cloud database that provides global distribution with strong consistency and horizontal scaling for OLTP workloads. Bigtable is eventually consistent across regions. Cloud SQL is regional. Firestore is eventually consistent and limited to single-region or limited multi-region.

Answer

Firestore

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Cloud SQL

Answer

Cloud Bigtable

Question 14

A company needs a database for an e-commerce application that requires strong consistency and the ability to scale horizontally across multiple regions. They expect high write throughput and need to support SQL queries. Which database should they choose?

Accepted Answer

Cloud Spanner. Cloud Spanner is a globally distributed, strongly consistent relational database that scales horizontally and supports SQL. Bigtable is NoSQL and eventually consistent. Cloud SQL is regional and does not scale horizontally. Firestore is NoSQL and eventually consistent across regions.

Answer

Cloud Bigtable

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Cloud SQL

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Firestore

Question 15

An engineer needs to create a Cloud SQL MySQL instance that can automatically failover to a standby in a different zone within the same region. Which configuration should be used?

Accepted Answer

Regional HA configuration. Cloud SQL HA configuration creates a primary and a standby instance in different zones within the same region. The standby is synchronously replicated and automatic failover occurs in under 60 seconds. Cross-region failover is not supported; read replicas are for read scaling and DR, not automatic failover. Zonal availability is a single-zone instance without HA.

Answer

Read replica in same zone

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Zonal availability configuration

Answer

Cross-region failover replica