PCD Practice Test 3 — 10 Questions

Question 1

A company is using Cloud Functions (2nd gen) to process files uploaded to Cloud Storage. The function needs to access a Cloud SQL (PostgreSQL) database. What is the most secure way to store and provide the database password to the function?

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

Accepted Answer

Use Secret Manager and access it via the Secret Manager API within the function.. Secret Manager is the recommended service for storing secrets with IAM controls. Option A is wrong because Cloud Storage buckets may have broader access and are not designed for secrets. Option B is wrong because hardcoding is insecure. Option D is wrong because KMS encrypts data but Secret Manager provides a simpler and more integrated secret storage solution.

Answer

Use Cloud KMS to encrypt the password and store it in environment variables.

Answer

Hardcode the password in the function code.

Answer

Store the password in a Cloud Storage bucket and read it at startup.

Question 2

A company is building a data processing pipeline that needs to ingest events from multiple sources, process them in order, and handle failures with retry. They also need to schedule periodic tasks. Which THREE services should they use? (Choose 3)

Accepted Answer

Cloud Scheduler. Cloud Pub/Sub for ingesting events with ordering, Cloud Tasks for retry handling, and Cloud Scheduler for scheduling periodic tasks. Cloud Workflows is for orchestration, Cloud Logging is for logs.

Answer

Cloud Workflows

Answer

Cloud Logging

Question 3

A company running a high-traffic e-commerce platform on Google Cloud experiences occasional data loss in their Cloud SQL database during failover events. The database is configured with a failover replica in a different zone. What is the most likely cause of the data loss?

Accepted Answer

The database is using asynchronous replication to the failover replica.. Cloud SQL uses synchronous replication for failover replicas by default, ensuring that transactions are committed on both the primary and the replica before acknowledging the write. If asynchronous replication is configured, the replica may lag behind the primary, and during a failover, any transactions not yet replicated are lost. This is the most likely cause of data loss during failover events.

Answer

Automated backups are not enabled.

Answer

The failover replica is configured as a read replica instead of a failover replica.

Answer

The database is not using regional persistent disks.

Question 4

A company is using Cloud Monitoring to track custom metrics published from an on-premises application using the Monitoring API. The metrics are published every 30 seconds. The team wants to create an alert that fires if the metric goes below a threshold for more than 1 minute. Which alert condition type should they use?

Accepted Answer

Metric type: custom.googleapis.com, condition: metric threshold (below value), duration: 60s. The requirement is to fire an alert when the metric value goes below a threshold for more than 1 minute. The 'metric threshold (below value)' condition type directly monitors a metric against a lower bound and evaluates the condition over the specified duration (60s) before triggering. This aligns with the need to detect sustained low values, not just a single data point.

Answer

Metric type: custom.googleapis.com, condition: metric lower bound, duration: 60s

Answer

Metric type: custom.googleapis.com, condition: metric change, duration: 60s

Answer

Metric type: custom.googleapis.com, condition: metric absence, duration: 60s

Question 5

A social media app uses Firestore in Native mode. The app has a feature that shows a user's recent posts. The query sorts by timestamp descending and limits to 10 results. As the user base grows, the queries become slow. Which optimization should you implement FIRST?

Accepted Answer

Create a composite index on (user_id, timestamp) for the posts collection. The query filters by `user_id` and sorts by `timestamp` descending, which requires a composite index on `(user_id, timestamp DESC)` to avoid a full collection scan. Without this index, Firestone performs a sort in memory, which becomes slow as the dataset grows. Creating the composite index allows Firestore to serve the query directly from the index, dramatically improving performance.

Answer

Increase the Firestore quota for reads

Answer

Use Cloud SQL for this query instead of Firestore

Answer

Denormalize the user’s recent posts into a subcollection

Question 6

A media streaming company uses Cloud Storage to store video files. Users upload files through a web application, and the files are streamed directly from Cloud Storage. They want to reduce latency for users in different regions. Which configuration should they apply?

Accepted Answer

Set up Cloud CDN with the Cloud Storage bucket as origin.. Cloud CDN caches video content at edge locations worldwide, reducing latency for users by serving content from the nearest edge cache instead of the origin Cloud Storage bucket. This directly addresses the requirement to reduce latency for users in different regions without modifying the storage architecture.

Answer

Enable Object Lifecycle Management to move objects to Nearline storage.

Answer

Configure Cloud Storage transfer service to replicate data to multiple buckets.

Answer

Use a multi-region Cloud Storage bucket and enable requester-pays.

Question 7

A company needs to perform complex transformations and join data from Cloud SQL, Cloud Storage, and Pub/Sub to load into BigQuery. Which Google Cloud service is designed for this ETL/ELT workload?

Accepted Answer

Dataflow

Answer

Cloud Functions

Answer

Cloud Run

Answer

Dataproc

Question 8

A company runs an e-commerce application with a relational database (PostgreSQL) for orders and inventory. They need to store clickstream data for real-time personalization, with a flexible schema and sub-second read latency. Which database best suits the clickstream workload?

Accepted Answer

Firestore

Answer

BigQuery

Answer

Cloud Spanner

Answer

Cloud Bigtable

Question 9

A company runs a microservices application on Google Kubernetes Engine. They use Cloud SQL for persistent data. Recently, during a traffic spike, the application experienced increased latency and some requests failed with timeout errors. The team observed that the Cloud SQL CPU utilization spiked to 100%, and the GKE pods had high memory usage. They are using a standard Cloud SQL tier (db-n1-standard-2). Which course of action would best improve the application's performance and reliability?

Accepted Answer

Implement caching with Memorystore for frequently accessed data.. The primary bottleneck is the Cloud SQL CPU spiking to 100% under heavy read traffic. Implementing Memorystore (Redis) caching offloads repeated read queries from the database, reducing CPU load and query latency. This directly addresses the root cause—database CPU exhaustion—without requiring a larger database instance or adding replicas that would still be limited by the same CPU.

Answer

Upgrade Cloud SQL to a higher tier with more CPU.

Answer

Increase the number of replicas in GKE to reduce load per pod.

Answer

Add read replicas to Cloud SQL.

Question 10

Refer to the exhibit. The Cloud Build fails with an error that the image name is invalid. What is the most likely cause?

Accepted Answer

The substitution variable $MY_PROJECT is not a valid substitution because it is not prefixed with underscore.. In Cloud Build, user-defined substitution variables must be prefixed with an underscore. The variable `$MY_PROJECT` lacks the required underscore prefix, making it invalid. This causes the image name to be malformed, leading to the 'invalid image name' error.

Answer

The push step should be after the deploy step.

Answer

The Docker build step fails because the Dockerfile is missing.

Answer

The image name contains uppercase letters that are not allowed.