PCD Practice Test 28 — 15 Questions

Question 1

An e-commerce company wants to use Cloud SQL for PostgreSQL with high availability (HA) in the same region. What is the RPO (Recovery Point Objective) of Cloud SQL HA configuration?

Accepted Answer

0 (zero). Cloud SQL for PostgreSQL high availability uses a regional configuration with a primary instance and a standby instance in a different zone, synchronized via synchronous replication. Because every committed transaction is written to both the primary and standby before acknowledgment, the standby is always current, giving an RPO of zero — no committed data is lost in a failover.

Answer

Up to 1 hour

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Up to 5 minutes

Answer

Depends on the database size

Question 2

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 3

A company is migrating a MySQL 5.7 database to Cloud SQL for MySQL 8.0. Their application uses utf8 charset and GROUP BY with nonstandard behavior (e.g., missing expressions in SELECT list). After migration, they notice queries that previously ran now fail. What is the most likely cause?

Accepted Answer

ONLY_FULL_GROUP_BY SQL mode is enabled by default in MySQL 8.0.. MySQL 8.0 enables the ONLY_FULL_GROUP_BY SQL mode by default, which requires that all columns in the SELECT list, HAVING condition, or ORDER BY list be functionally dependent on the GROUP BY columns or aggregated. Queries that previously ran under MySQL 5.7 (where this mode was not enabled by default) will now fail with an error if they reference nonaggregated columns not listed in GROUP BY.

Answer

The caching_sha2_password plugin changed authentication.

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JSON data type behavior changed in MySQL 8.0.

Answer

The utf8 charset is not supported in MySQL 8.0.

Question 4

A developer needs to build a CI/CD pipeline that automatically tests and deploys a Node.js application to Cloud Run whenever a pull request is merged to the main branch. Which Google Cloud service should be used to trigger the pipeline?

Accepted Answer

Cloud Build. Cloud Build is the correct service because it is Google Cloud's fully managed CI/CD platform that can automatically trigger pipeline executions in response to repository events, such as a pull request merge to the main branch. By configuring a Cloud Build trigger with a source repository (e.g., Cloud Source Repositories, GitHub, or Bitbucket), the developer can define build steps to test the Node.js application and deploy it to Cloud Run using the `gcloud run deploy` command or a dedicated builder. This makes Cloud Build the native and most direct choice for building, testing, and deploying to Cloud Run in a single automated pipeline.

Answer

Cloud Functions

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Cloud Deploy

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App Engine

Question 5

A financial services company needs a globally distributed relational database with strong ACID transactions and high availability across regions. They anticipate unpredictable traffic spikes and need to pay only for the resources they use. Which Google Cloud database and scaling approach is most suitable?

Accepted Answer

Cloud Spanner with processing units and auto-scaling. Cloud Spanner provides global distribution, strong consistency, and ACID transactions. With fine-grained scaling using processing units and auto-scaling, it can automatically adjust capacity based on demand, optimizing cost.

Answer

Cloud SQL for PostgreSQL with cross-region replication

Answer

Bigtable with replication

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Cloud Spanner with node-based scaling and manual resizing

Question 6

You are tuning a Cloud Bigtable table used for analytics. One column family, 'data', contains both frequently accessed columns (e.g., 'price', 'volume') and rarely accessed columns (e.g., 'raw_json'). To optimize performance and cost, what column family design is recommended?

Accepted Answer

Create two column families: 'core' for frequently accessed columns and 'extended' for rarely accessed columns. Separating columns into different column families based on access patterns is a best practice. Frequently accessed columns should be in one column family (e.g., 'core'), and rarely accessed columns in another (e.g., 'extended'). This allows Bigtable to optimize storage and read performance.

Answer

Use separate tables for each access pattern

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Store rarely accessed columns as a JSON string in a single column

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Place all columns in a single column family for simplicity

Question 7

A developer is deploying a microservice on GKE that needs to be accessible only from within the same VPC network. The microservice must have a stable, internal IP address that does not change when pods are updated. Which options should be used?

Accepted Answer

Use a Service of type LoadBalancer with the annotation 'cloud.google.com/load-balancer-type: Internal'.. Deploying a Service of type LoadBalancer with the annotation 'cloud.google.com/load-balancer-type: Internal' creates an internal TCP/UDP load balancer within the VPC network. This provides a stable, internal IP address that persists across pod updates, as the load balancer's IP is independent of the underlying pods and is managed by Google Cloud's networking layer.

Answer

Use a Service of type NodePort with a static reservation.

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Use a Service of type ClusterIP with a static IP.

Answer

Use a Service of type ExternalName pointing to the pods' internal IPs.

Question 8

A company is migrating a MySQL 5.7 database to Cloud SQL for MySQL 8.0. They have many queries using GROUP BY that return different results in 8.0. What is the most likely cause?

Accepted Answer

The sql_mode is different between MySQL 5.7 and 8.0.. MySQL 8.0 changed the default sql_mode to include ONLY_FULL_GROUP_BY, which was not enabled by default in 5.7. This mode requires that all columns in the SELECT list, HAVING condition, or ORDER BY list be functionally dependent on the GROUP BY columns or aggregated. Queries that previously returned arbitrary values for non-aggregated columns now either error out or produce different results because the server enforces stricter grouping semantics. Thus, the most likely cause is the difference in sql_mode between the two versions.

Answer

The character set changed from utf8 to utf8mb4.

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The authentication plugin changed from mysql_native_password to caching_sha2_password.

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The storage engine changed from MyISAM to InnoDB.

Question 9

An organization has data in Amazon S3 that they want to query from BigQuery without moving it. Which BigQuery feature should they use?

Accepted Answer

BigQuery Omni. BigQuery Omni allows querying data across clouds, including Amazon S3, without moving the data.

Answer

Cloud Storage transfer service to copy data to GCS first

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BigQuery federated queries with AWS Glue

Answer

Bigtable federation

Question 10

A development team uses Cloud Build for CI/CD with a monorepo containing multiple microservices. They want to implement a strategy where only the services affected by a commit are built and deployed. Which approach best achieves this?

Accepted Answer

Use multiple Cloud Build triggers, one per service, each with a path filter for its directory. Cloud Build triggers support path filters that allow you to specify which directories or files should initiate a build. By creating one trigger per microservice directory, only the service whose code has changed will be built and deployed, which is the most efficient and native approach for a monorepo with multiple services.

Answer

Use a single Cloud Build trigger with a condition to check changed files

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Use Cloud Functions to detect changes and trigger builds

Answer

Use a single Cloud Build trigger with a bash script to detect changes

Question 11

An e-commerce platform uses Cloud SQL for PostgreSQL. They need to reduce read load on the primary instance and provide low-latency reads for geographically distributed users. Which configuration should they implement?

Accepted Answer

Add read replicas in multiple regions. Cloud SQL for PostgreSQL read replicas can be deployed in multiple regions, and each replica serves reads with low latency to users in its region while offloading the primary. This directly reduces read load on the primary and satisfies the geographic latency requirement without changing the database engine.

Answer

Use Cloud CDN to cache database responses

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Enable cross-region replication using Cloud SQL's built-in failover replica

Answer

Migrate to Cloud Spanner

Question 12

A company needs to run analytics on their Cloud SQL database without affecting OLTP performance. They want to use a read replica. What is the BEST practice?

Accepted Answer

Create a read replica in the same or different region and route analytics queries to it. Creating a read replica and routing analytics queries to it is the best practice because it offloads read-heavy analytical workloads from the primary instance, preserving OLTP performance. Read replicas can be in the same or different region, providing flexibility.

Answer

Run analytics directly on the primary instance

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Export the data to BigQuery periodically

Answer

Use Cloud SQL's HA instance for analytics

Question 13

A company is designing a web application that must scale horizontally to handle variable traffic. Which two practices should they implement to ensure the application is stateless and can scale without issues?

Accepted Answer

Offload session state to the user's browser using encrypted cookies.. Option B is correct because storing session state in encrypted client-side cookies keeps the application servers free of per-user state, so any instance in the pool can handle any request and horizontal scaling works without session affinity. Option D is correct because moving session state to an external cache such as Memorystore (Redis/Memcached) centralizes state outside the compute instances, allowing instances to be added or removed freely while all of them read the same session data. Option A is wrong because persisting session data in Cloud SQL still ties the application to server-side state and adds a relational database dependency that does not make the app stateless. Option C is wrong because deploying across multiple regional managed instance groups addresses availability and geographic distribution, not statelessness. Option E is wrong because sticky sessions create client affinity to a specific instance, which is the opposite of stateless design and hinders elastic horizontal scaling.

Answer

Persist session data in Cloud SQL to ensure durability.

Answer

Deploy the application across multiple regional managed instance groups.

Answer

Use sticky sessions to maintain client affinity.

Question 14

A company is deploying a production Cloud Bigtable instance for time-series data. They want high availability across zones and the ability to serve reads from a secondary location. Which TWO configurations should they implement?

Accepted Answer

Add a second cluster in a different zone within the same region. Option C is correct because adding a second cluster in a different zone within the same region gives the Cloud Bigtable instance multi-zone high availability, so the data remains available if one zone fails. Option E is correct because adding a cluster in a different region enables cross-region replication, which is what allows reads to be served from a secondary location. Options A, B, and D are not appropriate: a development instance type is for non-production/testing and does not provide the required HA; disabling replication would prevent serving reads from another location and defeat the purpose; and HDD storage is a cost/performance choice that does not address high availability or secondary-location reads.

Answer

Create a development instance type

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Disable replication to avoid conflicts

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Use HDD storage to reduce costs

Question 15

A developer is integrating a legacy on-premises application with Cloud Storage. The application generates files that must be uploaded to a bucket. The developer cannot install any additional software on the on-premises server. Which approach should the developer use?

Accepted Answer

Generate a signed URL and use an HTTP PUT request from the application.. A signed URL allows the legacy application to upload files directly to Cloud Storage using a standard HTTP PUT request, without installing any additional software or SDKs on the on-premises server. The signed URL embeds authentication credentials and permissions, so the application only needs an HTTP client, which is universally available. This satisfies the constraint of no additional software installation.

Answer

Use the gcloud CLI to copy files to the bucket.

Answer

Mount the bucket using Cloud Storage FUSE.

Answer

Deploy a Cloud Function that accepts file uploads and writes to the bucket.