PCD Practice Test 41 — 15 Questions

Question 1

Your Cloud Run service experiences high latency during traffic spikes. You need to reduce p95 latency without over-provisioning. Which action should you take?

Accepted Answer

Set min-instances to at least 5 for consistent baseline capacity.. Setting min-instances to at least 5 ensures that a baseline number of container instances are always warm and ready to handle incoming requests. This eliminates cold starts and reduces latency during traffic spikes because new requests can be immediately served by pre-warmed instances, rather than waiting for new containers to spin up. This approach directly reduces p95 latency without over-provisioning, as you only pay for the baseline instances when they are idle.

Answer

Set max-instances to a low number to ensure consistent resources.

Answer

Reduce the max-concurrency per container to 1.

Answer

Disable CPU throttling to always allocate CPU.

Question 2

Which Google Cloud database service provides automatic failover with synchronous replication and 0 RPO within a single region?

Accepted Answer

Cloud SQL (HA configuration). Cloud SQL with HA configuration provides synchronous replication to a standby instance within the same region and automatic failover with 0 RPO. Cloud Spanner, when configured as a regional instance, also offers synchronous replication across zones within the same region, automatic failover, and 0 RPO. Both services meet the criteria. In contrast, Cloud Bigtable uses asynchronous replication across clusters, and Firestore does not provide synchronous replication with 0 RPO within a single region.

Answer

Cloud Bigtable

Answer

Firestore

Question 3

A company has a Cloud Function that processes events from Cloud Pub/Sub. The function uses HTTP client libraries to call external APIs. The team notices that the function sometimes times out during high traffic. Which THREE actions should they take to improve reliability? (Choose THREE.)

Accepted Answer

Use Cloud Tasks to queue the API call invocations and process them asynchronously from the function.. (Use Cloud Tasks to queue the API call invocations and process them asynchronously from the function) is correct because it decouples the external API calls from the function execution, reducing the risk of timeouts during high traffic. Option C (Implement retry logic with exponential backoff for external API calls) is correct to handle transient failures from external APIs gracefully. Option D (Increase the Cloud Function timeout to 540 seconds) is correct to allow the function more time to complete processing, especially when waiting for external responses. Option A (Increase the allocated memory to 2GB) is incorrect because while more memory can improve performance for compute-intensive tasks, it does not directly address timeouts caused by external API dependencies. Option E (Reduce the maximum number of concurrent function instances) is incorrect because reducing concurrency would decrease throughput and could worsen latency under high load, not improve reliability.

Answer

Increase the allocated memory to 2GB.

Answer

Reduce the maximum number of concurrent function instances.

Question 4

A financial services company needs to maintain a backup of their Bigtable instance in a different geographic region. They want to restore the backup quickly in case of a regional failure. What should they do?

Accepted Answer

Create a Bigtable backup and restore it to a cluster in another region.. Bigtable backups are designed for exactly this use case: they are full, consistent copies of the table schema and data that can be restored to a different cluster in another region. This approach provides a fast, managed restore without the overhead of maintaining a hot standby or the complexity of export/import pipelines. Option C directly uses the Bigtable backup and restore feature, which is the recommended method for cross-region disaster recovery.

Answer

Set up a hot standby Bigtable cluster in another region using replication.

Answer

Use Cloud SQL cross-region backup copy feature.

Answer

Export the Bigtable data to Cloud Storage and import it into a new cluster.

Question 5

A company is migrating a monolithic Java application to Cloud Run. The application takes 10 minutes to start. What is the best deployment approach?

Accepted Answer

Optimize the Java application to start within 10 minutes and use startup CPU boost.. Cloud Run allows a maximum container startup time of 10 minutes (600 seconds) by default, and the startup CPU boost feature temporarily allocates additional CPU during startup to accelerate initialization. By optimizing the application to start within this limit and enabling startup CPU boost, the company can directly address the cold start issue without changing the deployment platform or architecture.

Answer

Migrate to App Engine Flexible Environment.

Answer

Use a custom runtime with a cold start optimization.

Answer

Increase the memory limit to 4 GB.

Question 6

A company is deploying a containerized application on Cloud Run that requires access to a Cloud SQL PostgreSQL instance. The application needs to connect to the database using private IP to minimize latency and avoid public internet exposure. The Cloud Run service and Cloud SQL instance are in the same region and project. The database user and password are stored in Secret Manager. Which two steps should the developer take to enable the connection? (Choose TWO.)

Accepted Answer

Grant the Cloud Run service account the Cloud SQL Client role.. The Cloud Run service account needs the Cloud SQL Client role to authenticate with Cloud SQL. Option D is correct because Cloud Run requires a VPC connector to access resources on a VPC network, and Private Services Access must be configured to allow Cloud Run to reach the Cloud SQL private IP. Option B is incorrect because the CLOUD_SQL_CONNECTION_NAME environment variable is used with the Cloud SQL Auth proxy, not with private IP. Option C is incorrect because enabling the Cloud SQL Admin API is a prerequisite but not a direct step for the connection itself; it is often already enabled. Option E is incorrect because the Cloud SQL Auth proxy is not needed when using private IP.

Answer

Set the CLOUD_SQL_CONNECTION_NAME environment variable in the Cloud Run service.

Answer

Enable the Cloud SQL Admin API.

Answer

Deploy the Cloud SQL Auth proxy as a sidecar container in Cloud Run.

Question 7

A developer is deploying a Node.js application to App Engine flexible environment. They need to install custom dependencies and run startup scripts. Which two configuration elements should they define in the app.yaml? (Choose two.)

Accepted Answer

entrypoint. A is correct because the `entrypoint` element in app.yaml for App Engine flexible environment specifies the command to run your application, allowing you to execute custom startup scripts and install dependencies before the main process starts. This is essential for Node.js apps that require custom build steps or runtime initialization beyond the default `npm start`.

Answer

env_variables

Answer

manual_scaling

Answer

network

Question 8

A company has a multi-module repository. They want to build only the modules that have changes. Which two features can they combine to achieve this? (Choose 2)

Accepted Answer

Build scripts that detect changes. Build scripts can be written to compare the current commit hash against the previous build's commit hash, or use git diff to detect which files have changed, and then conditionally execute build steps only for the affected modules. This approach gives fine-grained control over the build process and can be integrated into any CI/CD pipeline.

Answer

Cloud Build queue

Answer

Cloud Build substitutions

Answer

Cloud Source Repositories mirror

Question 9

Which Google Cloud database is best suited for high-throughput, low-latency caching to reduce load on a primary database?

Accepted Answer

Memorystore. Memorystore (managed Redis/Memcached) is the caching layer, providing sub-millisecond access times.

Answer

Cloud SQL

Answer

Firestore

Answer

Cloud Bigtable

Question 10

A startup needs a multi-model database architecture: relational for user profiles, document store for product catalog, and a key-value cache for sessions. Which approach is this called?

Accepted Answer

Polyglot persistence. Polyglot persistence refers to using different database types for different components of an application, each optimized for its use case.

Answer

Multi-cloud database strategy

Answer

Sharding

Answer

Database federation

Question 11

A company is migrating an on-premises Oracle database to Cloud SQL for PostgreSQL. They need to assess the compatibility of the existing schema and identify objects that need conversion. Which tool should they use?

Accepted Answer

Ora2Pg. Ora2Pg is an open-source tool designed to migrate Oracle schemas to PostgreSQL. It assesses compatibility, converts DDL, and reports unsupported features. DMS handles the data migration but doesn't provide schema analysis. Dataflow is for data transformation, not schema assessment.

Answer

gcloud sql import

Answer

Database Migration Service (DMS)

Answer

Cloud Dataflow

Question 12

A large e-commerce platform uses Cloud Bigtable to store user session data and product recommendations. They have a single cluster in a single zone. During a recent zone outage, the application became unavailable for 30 minutes because Cloud Bigtable was unreachable. The team needs to ensure high availability for the session data with a Recovery Time Objective (RTO) of less than 5 minutes and a Recovery Point Objective (RPO) of zero (no data loss). What should they do?

Accepted Answer

Add a second cluster in a different zone within the same region and use multi-cluster routing to automatically failover.. Adding a second Cloud Bigtable cluster in a different zone within the same region and enabling multi-cluster routing provides automatic failover with an RTO of under 5 minutes and an RPO of zero. Multi-cluster routing directs read and write requests to the nearest healthy cluster, and replication between clusters is synchronous within a region, ensuring no data loss during a zone outage.

Answer

Migrate the session data to Cloud Memorystore for Redis with persistence and replication.

Answer

Configure replication to a second cluster in a different region and use global routing to failover.

Answer

Use Cloud Bigtable's single-cluster replication to a different zone.

Question 13

You are using Cloud Bigtable to store time-series financial market data. To ensure high availability across zones, you configure cluster replication. What is the recommended replication topology for automatic failover?

Accepted Answer

Two clusters in different zones with replication enabled and multi-cluster routing. Bigtable supports replication across clusters in different zones within a region (or across regions). For automatic failover, you should use primary-secondary (also called single-cluster routing with failover) or multi-cluster routing. The recommended HA setup is to have two clusters in different zones with replication enabled.

Answer

Two clusters in the same zone

Answer

Single cluster with multi-node configuration

Answer

Three clusters in three regions

Question 14

A team uses Cloud Tasks to process orders asynchronously. Each order is enqueued after payment verification. Processing involves calling an external shipping API that occasionally returns 503 (Service Unavailable). The Cloud Tasks queue is configured with default retry parameters: max retries = 100, max retry duration = 1 hour. The team notices that some orders are never processed; they remain in the queue until the max retry duration expires and then are discarded. What is the most likely cause and solution?

Accepted Answer

Increase the max retry duration to 24 hours.. The default Cloud Tasks retry parameters include a max retry duration of 1 hour. If an order repeatedly fails due to 503 errors from the external shipping API, the task will be retried up to 100 times within that hour. However, if the API remains unavailable for longer than the max retry duration, the task will be discarded even if the retry count hasn't been exhausted. Increasing the max retry duration to 24 hours gives the external API more time to recover, ensuring that orders are not prematurely discarded.

Answer

Set a custom retry deadline of 2 hours.

Answer

Use exponential backoff in the task handler instead of relying on Cloud Tasks.

Answer

Check the task queue rate limits and increase max dispatches per second.

Question 15

A developer wants to view real-time logs from a running application on Compute Engine. Which two methods can they use to stream logs? (Choose two.)

Accepted Answer

Using the Logs Explorer's 'Stream logs' feature. The Logs Explorer in the Google Cloud Console provides a 'Stream logs' feature that allows you to view real-time log entries as they are ingested by Cloud Logging. This is ideal for monitoring a running Compute Engine instance without needing to SSH into it. Option C is correct because the `gcloud logging tail` command streams log entries from Cloud Logging in real time, using the Logging API's tail method, and can filter by resource type (e.g., `gce_instance`) or log name.

Answer

Using gcloud compute ssh and running journalctl -f

Answer

Using Cloud Monitoring's metrics explorer

Answer

Using gcloud app logs tail