PCD Practice Test 43 — 15 Questions

Question 1

A company has a multi-region Cloud Run service with traffic splitting between revisions. They notice that a newly rolled-out revision is receiving 0% of traffic even though they set traffic to 100% via the console. The revision shows 'Ready: Yes'. What is the most likely cause?

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

Accepted Answer

The revision has a tag but no traffic percentage assigned; the tag is being used for routing.. When a revision shows 'Ready: Yes' but receives 0% traffic despite setting 100% via the console, the most likely cause is that the revision has a tag assigned but no traffic percentage. In Cloud Run, tags are used for direct URL routing (e.g., for testing) and do not receive any traffic from the service's main URL unless a traffic percentage is explicitly assigned. The console's traffic splitting UI allows setting a tag without a percentage, which can lead to this confusion.

Answer

The revision has a low CPU limit causing it to be throttled.

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The revision is not healthy because of a misconfigured health check.

Answer

The revision has a concurrency setting of 0, which is invalid.

Question 2

An online gaming company uses Cloud SQL for MySQL for player data and wants to synchronise some of that data to a BigQuery dataset daily for analytics. The data transformations are complex (e.g., aggregations, joins with other sources). Which service should they use to build this pipeline?

Accepted Answer

Dataflow pipeline using JDBC source and BigQuery sink. Dataflow provides a fully managed, serverless execution environment for Apache Beam pipelines, which can read from Cloud SQL via a JDBC source, perform complex transformations (aggregations, joins with other sources) in a distributed manner, and write the results to BigQuery as a sink. This directly addresses the requirement for complex, daily transformations that are beyond the capabilities of simpler services.

Answer

Datastream with BigQuery as destination

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BigQuery Data Transfer Service for Cloud SQL

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Cloud Functions triggered by Cloud Scheduler

Question 3

A Cloud SQL for PostgreSQL instance is experiencing high query latency. The database has a high number of read replicas and is used for reporting. The team has identified that index scans are not being used effectively. Which THREE actions should they take to improve query performance?

Accepted Answer

Analyze table statistics using VACUUM ANALYZE.. `VACUUM ANALYZE` updates table statistics that the PostgreSQL query planner relies on to choose efficient index scans. Stale statistics can cause the planner to underestimate the selectivity of index conditions, leading to sequential scans instead of index scans, which increases latency. Regular analysis ensures the planner has accurate data distribution information to optimize query execution plans.

Answer

Enable automatic storage increase.

Answer

Create additional read replicas.

Question 4

Which TWO are best practices for testing containerized applications on Google Cloud?

Accepted Answer

Use Cloud Build to build and test containers.. Cloud Build is a managed CI/CD platform that can build container images from source code and execute tests as part of the build pipeline. It integrates natively with Google Cloud services like Container Registry and Artifact Registry, and supports custom build steps, making it an ideal tool for building and testing containerized applications in a consistent, automated environment.

Answer

Use Kubernetes for testing only.

Answer

Use Distroless images for testing.

Answer

Use a different base image for testing than production.

Question 5

A company wants to monitor the CPU utilization of their Compute Engine instances and automatically trigger scaling actions if utilization exceeds 80% for 5 minutes. Which service should they use?

Accepted Answer

Managed instance group autoscaler. Managed instance group (MIG) autoscaler is the correct service because it is designed to automatically adjust the number of Compute Engine instances based on configured utilization metrics. By setting a target CPU utilization of 80% over a 5-minute window, the autoscaler will add or remove instances to maintain that threshold, directly meeting the requirement for automatic scaling actions.

Answer

Cloud Monitoring

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Cloud Scheduler

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Cloud Load Balancing

Question 6

Which THREE are valid uses of Cloud Trace? (Choose three.)

Accepted Answer

Identifying latency bottlenecks in a distributed application. Cloud Trace is a distributed tracing system that captures latency data from applications, allowing you to identify performance bottlenecks across services. Option A is correct because Cloud Trace provides detailed traces that show the time spent in each component of a distributed application, enabling you to pinpoint where delays occur.

Answer

Monitoring CPU usage of a Compute Engine instance

Answer

Exporting traces to Prometheus for long-term storage

Question 7

A team uses Cloud Build to deploy applications that need to access a Cloud SQL database in a VPC. They want to avoid exposing the database to the public internet. Which configuration is required?

Accepted Answer

Configure Cloud Build to use a private pool in the same VPC as the database. Cloud Build private pools run in a customer-managed VPC, allowing workers to directly access resources like Cloud SQL instances via private IP without traversing the public internet. This configuration ensures the database is never exposed to the public internet, meeting the security requirement.

Answer

Enable VPC Network Peering between Cloud Build and the database VPC

Answer

Use Cloud SQL Proxy in a Cloud Build step

Answer

Use a public IP on Cloud SQL and restrict by IP whitelist

Question 8

A developer is building a CI/CD pipeline for a microservices application. The pipeline should build a container image, run unit tests, and deploy to Google Kubernetes Engine (GKE) only if all tests pass. Which Google Cloud service is best suited for orchestrating this pipeline?

Accepted Answer

Cloud Build. Cloud Build is the correct choice because it is a fully managed CI/CD platform that natively supports building container images, running unit tests, and deploying to GKE. It can be configured with a cloudbuild.yaml file to define steps for building, testing, and deploying, and it only proceeds to the deploy step if all prior steps (including tests) succeed. This makes it the best fit for orchestrating the entire pipeline in a single, integrated service.

Answer

Compute Engine

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Cloud Run

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Cloud Functions

Question 9

You want to migrate an on-premises MySQL database to Cloud SQL with minimal downtime. The source database is 500 GB. Which approach is recommended?

Accepted Answer

Create a Cloud SQL read replica from the on-premises source using Database Migration Service. Database Migration Service (DMS) is specifically designed for minimal-downtime migrations from on-premises MySQL to Cloud SQL. It uses continuous replication (CDC) to keep the source and target synchronized, allowing a short cutover window after the initial 500 GB data load. This approach avoids the downtime required by export/import or file-copy methods.

Answer

Use BigQuery Data Transfer Service to migrate the data

Answer

Copy the data files to a Cloud Storage bucket and use the Cloud SQL import

Answer

Export the database using mysqldump and import to Cloud SQL using gcloud sql import

Question 10

A company is migrating a legacy monolithic application to Google Cloud. They want to minimize code changes and operational overhead while improving scalability. The application currently uses a relational database and stores user-uploaded images on a local filesystem. Which combination of Google Cloud services should they use?

Accepted Answer

Cloud SQL for the database and Cloud Storage with Cloud CDN for images. Cloud SQL provides a fully managed relational database that requires minimal code changes when migrating from an existing relational database, while Cloud Storage with Cloud CDN handles user-uploaded images with scalable object storage and low-latency content delivery. This combination minimizes operational overhead by eliminating the need to manage database servers or file servers, and improves scalability through automatic replication and global edge caching.

Answer

Cloud Spanner for the database and Cloud Storage for images

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Cloud Firestore for the database and Cloud Storage with Cloud CDN for images

Answer

Compute Engine with attached SSD persistent disks for both database and images

Question 11

You need to design a Firestore database for a mobile chat application that supports real-time updates and offline access. The app requires that users can only read and write their own messages. Which three configurations should you implement? (Choose three.)

Accepted Answer

Enable offline persistence in the client SDK. Enabling offline persistence in the Firestore client SDK allows the mobile chat app to cache data locally, ensuring that users can read and write their own messages even when the device is temporarily offline. This is essential for a chat application that must support real-time updates and offline access, as Firestore automatically synchronizes local changes with the server when connectivity is restored.

Answer

Use Cloud SQL instead of Firestore for stronger consistency

Answer

Use Firestore Datastore mode

Question 12

A web application uses Cloud SQL for MySQL. The team expects a sudden spike in read-only traffic from a reporting tool. What should they use to offload read queries?

Accepted Answer

Read replicas. Read replicas in Cloud SQL for MySQL allow you to offload read traffic from the primary instance by creating one or more read-only copies. This is the correct approach for handling a sudden spike in read-only queries from a reporting tool, as it distributes the load without affecting write performance or requiring application changes beyond updating the connection string.

Answer

Automatic storage increase

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Cross-region replication

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Failover replica

Question 13

A company runs a batch job daily that processes large files from Cloud Storage and stores results in BigQuery. The job requires significant compute for about 10 minutes and is fault-tolerant. Which compute option is most cost-effective?

Accepted Answer

Preemptible VM. Preemptible VMs offer the same compute capacity as regular VMs at a significantly lower cost (up to 80% discount), and since the batch job runs for only 10 minutes daily and is fault-tolerant, it can handle the occasional preemption without data loss. The job's short duration and fault tolerance make preemptible instances ideal, as they can be restarted if terminated.

Answer

Cloud Run Jobs

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Always-on Compute Engine VM

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GKE cluster with a single node

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Cloud Functions (9-minute timeout)

Question 14

A team is using Cloud Monitoring to set up an alerting policy for a Compute Engine instance that runs a web server. The team wants to be notified if the instance's CPU utilization exceeds 80% for 5 minutes. Which threshold type should they use?

Accepted Answer

Metric threshold. A metric threshold alerting policy directly monitors a numeric metric (e.g., CPU utilization) and triggers when the value exceeds a defined threshold (80%) for a specified duration (5 minutes). This is the standard approach for simple threshold-based alerts on a single metric in Cloud Monitoring.

Answer

Ratio threshold

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MQL (Monitoring Query Language)

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Forecast threshold

Question 15

An application deployed on Google Kubernetes Engine (GKE) is experiencing intermittent high latency. The operations team wants to quickly identify which specific code path is causing the delay. What should they use?

Accepted Answer

Enable Cloud Trace and analyze trace spans.. Cloud Trace is designed specifically for latency analysis in distributed systems like GKE. It captures end-to-end request latency and breaks it down into individual spans, each representing a specific code path or service call. By analyzing these spans, the operations team can pinpoint which exact code path (e.g., a database query, external API call, or internal function) is causing the intermittent high latency.

Answer

Use Cloud Profiler to identify memory leaks.

Answer

Set up a Cloud Monitoring uptime check.

Answer

Review Cloud Logging logs to find error messages.