PCD Practice Test 16 — 15 Questions

Question 1

Which TWO features are provided by Google Cloud Deploy? (Choose 2.)

Accepted Answer

Rollback to a previous deployment revision.. Google Cloud Deploy is a managed continuous delivery service that automates the rollout of applications to Google Kubernetes Engine (GKE) or GKE Enterprise clusters. It supports rollback to a previous deployment revision (A) by reverting the target cluster to the last known good state, and it provides automated canary analysis (C) by integrating with Cloud Monitoring to verify deployment health metrics before progressing traffic shifts.

Answer

Run containers without managing infrastructure.

Answer

Build container images from source code.

Answer

Manage Kubernetes clusters across multi-cloud environments.

Question 2

An operations team is configuring a Cloud Monitoring alerting policy for a critical application. They want to ensure that alerts are only fired when an anomaly persists for at least 5 minutes to reduce noise. Which condition configuration should they use?

Accepted Answer

Use a 'Metric Threshold' condition and set the 'for' parameter to 300 seconds.. The 'for' parameter in a Metric Threshold condition specifies the duration (in seconds) that a metric must continuously violate the threshold before the alert fires. Setting it to 300 seconds ensures the anomaly persists for at least 5 minutes, reducing noise from transient spikes. This is the standard approach in Cloud Monitoring for sustained condition evaluation.

Answer

Configure 'Evaluation Missing Data' to '5 minutes'.

Answer

Set the condition type to 'Metric Absence' with a 5-minute duration.

Answer

Use 'Never retrigger' state with 5-minute window.

Question 3

A Cloud Spanner database has a table Orders with a child table OrderItems. Queries often join Orders and OrderItems on OrderID. Which schema design optimizes performance for these joins?

Accepted Answer

Make OrderItems an interleaved table under Orders. Interleaved tables store child rows with their parent row in the same split, colocating related data and reducing cross-node communication. This is the correct optimization for parent-child joins.

Answer

Define a secondary index on OrderItems.OrderID

Answer

Use a global index on Orders.OrderID

Answer

Denormalize OrderItems data into the Orders table

Question 4

An application running on Compute Engine generates structured logs. The operations team needs to parse a specific field from the logs and create a metric that counts occurrences of a particular value. They want the metric to be available for alerting with minimal delay. What should they do?

Accepted Answer

Create a log-based metric in Cloud Logging. Log-based metrics in Cloud Logging are designed to extract specific fields from structured logs and count occurrences of particular values with near-real-time latency, making them ideal for alerting with minimal delay. They are natively integrated with Cloud Monitoring, so the metric is automatically available for alerting policies without additional infrastructure or data movement.

Answer

Export logs to BigQuery and use scheduled queries

Answer

Write a Cloud Function to process logs from Pub/Sub

Answer

Use the Cloud Monitoring agent to collect logs

Question 5

You need to design a system that handles both high-frequency OLTP transactions and real-time analytical queries on the same dataset with low latency. Which Google Cloud database should you choose?

Accepted Answer

AlloyDB. AlloyDB is a fully managed, PostgreSQL-compatible database that uses a columnar engine to accelerate analytical queries while maintaining high-throughput OLTP performance. Its architecture separates compute and storage, allowing independent scaling of transactional and analytical workloads. The columnar engine automatically caches frequently accessed data in a columnar format, enabling real-time analytics on the same dataset without impacting OLTP latency. This makes AlloyDB ideal for mixed workloads requiring low latency for both transactions and analytics.

Answer

BigQuery

Answer

Cloud SQL for PostgreSQL

Answer

Cloud Spanner

Question 6

You need to design a database for a global inventory management system that requires strong consistency across regions and can handle millions of updates per day. The system must maintain ACID transactions across multiple warehouses. Which database service and configuration would you choose?

Accepted Answer

Cloud Spanner multi-region instance. Cloud Spanner is the only Google Cloud database service that provides ACID transactions across regions with strong external consistency, making it ideal for a global inventory system requiring millions of updates per day. Its multi-region instance configuration uses synchronous replication and the TrueTime API to ensure linearizable transactions, meeting the need for strong consistency across warehouses.

Answer

Bigtable with cluster replication

Answer

Firestore in multi-region mode

Answer

Cloud SQL with cross-region replicas

Question 7

A global e-commerce company needs a database for its order processing system that can handle high write throughput across multiple regions, with strong consistency and 99.999% availability. The data model is relational with joins. Which database should they choose?

Accepted Answer

Cloud Spanner. Cloud Spanner is the correct choice because it is a globally distributed, horizontally scalable relational database service that provides strong consistency across regions, 99.999% availability (five nines), and supports SQL joins. It uses synchronous replication and the TrueTime API to deliver ACID transactions at global scale, meeting the high write throughput and consistency requirements.

Answer

Firestore

Answer

Cloud SQL (PostgreSQL)

Answer

Cloud Bigtable

Question 8

A developer runs the above command and receives a successful deployment. However, the service is not accessible from the internet. The service is intended to be public. What should the developer check next?

Accepted Answer

The service IAM policy to ensure allUsers has Cloud Run Invoker role. Cloud Run services are private by default; even after a successful deployment, the service will not be accessible from the internet unless the IAM policy explicitly grants the `roles/run.invoker` role to `allUsers`. Without this permission, any HTTP request from outside the project will be denied with a 403 Forbidden error, regardless of the service's health or region.

Answer

The region us-central1 is not available

Answer

The Cloud Run service has a custom domain mapped

Answer

The container image is healthy

Question 9

An e-commerce company is designing a global product inventory system that requires strong consistency across regions, horizontal scaling for millions of users, and 99.999% availability. Which Google Cloud database meets all these requirements?

Accepted Answer

Cloud Spanner. Cloud Spanner is the only Google Cloud database that provides globally distributed ACID transactions with strong consistency, horizontal scaling, and 99.999% SLA.

Answer

Firestore

Answer

Cloud Bigtable

Answer

Cloud SQL for PostgreSQL

Question 10

Refer to the exhibit. A Cloud Build config deploys a new image to GKE. After the build succeeds, the pods restart with the new image but the application configuration is unchanged. What is the most likely cause?

Accepted Answer

The ConfigMap is not updated with the new configuration values.. A is correct because a Cloud Build config that deploys a new image to GKE does not automatically update the ConfigMap. The pods restart with the new image, but the application configuration remains unchanged because the ConfigMap still holds the old values. To apply new configuration, the ConfigMap must be updated separately, and the pods must be restarted or redeployed to pick up the changes.

Answer

The deployment rollout strategy is set to Recreate, causing downtime.

Answer

The new image is not being pulled because of imagePullPolicy: IfNotPresent.

Answer

The GKE cluster does not have sufficient permissions to pull from Container Registry.

Question 11

A team wants to deploy infrastructure as code on Google Cloud. They need a declarative language that supports modularity and state management. Which tool should they choose?

Accepted Answer

Terraform.. Terraform is the correct choice because it is a declarative infrastructure-as-code tool that supports modularity through reusable modules and state management via state files (local or remote backends like Cloud Storage). It allows teams to define Google Cloud resources in HashiCorp Configuration Language (HCL) and track resource changes over time, enabling safe, incremental updates.

Answer

Cloud Deployment Manager.

Answer

Cloud Shell.

Answer

gcloud commands.

Question 12

A developer is troubleshooting a deployment on Cloud Run. The service fails with 'Container failed to start' error. The container image is built from a Dockerfile that uses CMD ['npm', 'start']. What is the most likely cause?

Accepted Answer

The application does not listen on the port specified by the PORT environment variable.. Cloud Run requires the containerized application to listen on the port specified by the PORT environment variable (default 8080). If the application is hardcoded to listen on a different port (e.g., 3000) or does not read the PORT variable, Cloud Run's health checks and routing will fail, resulting in a 'Container failed to start' error. The CMD instruction is correct for starting npm, but the application must bind to the correct port.

Answer

The Dockerfile uses CMD instead of ENTRYPOINT.

Answer

The container image is too large and exceeds the memory limit.

Answer

The Cloud Run service does not have permission to pull the image from Container Registry.

Question 13

During a MySQL to Cloud SQL migration using DMS, the migration job completes the full dump and CDC phases, but the cutover step fails. The error says 'Source database write operations still occurring'. What should the engineer do to complete cutover?

Accepted Answer

Stop all write operations to the source database, then promote the Cloud SQL replica.. Database Migration Service (DMS) cutover requires a quiescent source: the migration job continuously replicates changes via CDC, and the cutover step only succeeds when no new writes are being applied to the source. The error 'Source database write operations still occurring' is DMS's explicit signal that the source is still active, so the engineer must stop all application writes to the source MySQL instance and then promote the Cloud SQL replica to make it the new primary. Promoting without stopping writes would cause data divergence and potential data loss, which is why DMS blocks the cutover until the source is quiet.

Answer

Restart the DMS job from the beginning.

Answer

Manually apply remaining changes to Cloud SQL using a SQL script.

Answer

Increase the source database's binary log retention period.

Question 14

A company is using Bigtable for real-time analytics and notices that certain row keys are causing hot spots. Which tool should they use to identify the hot spot patterns?

Accepted Answer

Key Visualizer. Bigtable Key Visualizer is designed to analyze access patterns and identify hot spots by visualizing row key distribution and traffic. It helps optimize row key design. The other options are general monitoring or optimization tools not specific to Bigtable key analysis.

Answer

Profiler

Answer

Cloud Monitoring workspace

Answer

Cloud Trace

Question 15

A developer is building a microservices application on Cloud Run. One service needs to make authenticated HTTP requests to another Cloud Run service in the same project. What is the best practice for authentication?

Accepted Answer

Use IAM roles on the target service and call it with the appropriate identity token from the metadata server. Cloud Run service-to-service authentication is best done using an identity token from the metadata server and setting IAM on the target service. Option A is not recommended as API keys are for external clients. Option B uses the default compute service account, which may have broader permissions than needed and is not the best practice for service-to-service auth. Option C uses OAuth2 client credentials, which are for external applications, not for internal service-to-service calls.

Answer

Use API keys

Answer

Use Cloud Run's built-in service-to-service authentication with the default compute service account

Answer

Use OAuth2 client credentials