Google PCA Analysing and Optimising Technical and Business Processes Practice Test 2 — 15 Questions

Question 1

A company running a globally distributed application uses Firestore in Native mode. They need strong consistency for reads and writes across multiple regions. Which deployment strategy should they use?

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

Accepted Answer

Use Cloud Spanner. Firestore supports multi-region replication but only provides eventual consistency across regions. Cloud Spanner offers strong consistency globally. Firestore in Datastore mode also offers eventual consistency. Therefore, for strong consistency across regions, Cloud Spanner is required.

Answer

Use Bigtable with replication

Answer

Use Firestore in Datastore mode

Answer

Use Firestore in multi-region (nam5 or eur3)

Question 2

A company uses Cloud CDN to serve static content from a Cloud Storage bucket. They update the content every 2 hours, but users sometimes see stale content for up to 24 hours. They need users to see the latest content within 5 minutes of an update. Which action should they take?

Accepted Answer

Set a short max-age TTL (e.g., 5 minutes) on the objects. To ensure content is served fresh, they should set a short max-age (cache TTL) on the object metadata or via the bucket's default object holding. Invalidating the cache is a reactive measure, but setting a short TTL ensures that cache entries expire quickly. Cache modes affect query string handling, not TTL. Cache keys affect how content is cached but not the freshness duration.

Answer

Use cache invalidation after each update

Answer

Use custom cache keys

Answer

Change cache mode to CACHE_ALL_STATIC

Question 3

A company runs a batch processing job that uses preemptible VMs. The job occasionally fails due to VM preemption. They want to improve reliability without significantly increasing cost. Which TWO actions should they take? (Choose TWO.)

Accepted Answer

Use a managed instance group with autoscaling and preemptible VMs. Using a managed instance group (MIG) with autoscaling and preemptible VMs can automatically recreate instances if preempted. Implementing a retry logic in the application to re-run failed tasks also improves reliability. Using sole-tenant nodes or adding more nodes increases cost or complexity. Switching to regular VMs increases cost.

Answer

Use sole-tenant nodes to reduce risk of preemption

Answer

Switch to regular (non-preemptible) VMs

Answer

Increase the number of preemptible VMs

Question 4

A company is adopting Site Reliability Engineering (SRE) practices. After a major incident, they want to conduct a review to understand what went wrong and how to prevent recurrence, without blaming individuals. Which SRE practice should they follow?

Accepted Answer

Conduct a blameless postmortem. A blameless postmortem focuses on learning from incidents without assigning blame. Error budgets are for measuring reliability, SLOs/SLIs are for defining targets, and capacity planning is for scaling.

Answer

Define SLOs and SLIs

Answer

Create an error budget policy

Answer

Perform capacity planning

Question 5

A company is migrating 50 on-premises VMs to Compute Engine. They need to minimise downtime and want an automated lift-and-shift migration that replicates disks incrementally. Which Google Cloud service should be used?

Accepted Answer

Migrate for Compute Engine. Migrate for Compute Engine (formerly Velostrata) performs agentless, incremental replication of VM disks to Compute Engine, enabling minimal downtime migrations.

Answer

Database Migration Service

Answer

Storage Transfer Service

Answer

Transfer Appliance

Question 6

A company runs batch analytics workloads on Compute Engine that can tolerate interruptions. They want to reduce compute costs by up to 60-90%. Which compute option is the most cost-effective?

Accepted Answer

Preemptible VMs. Preemptible VMs offer significant discounts (60-90%) for interruptible workloads. Spot VMs are the newer equivalent with same discounts but no max runtime limit.

Answer

On-demand VMs

Answer

Committed use discounts (1-year)

Answer

Sustained use discounts

Question 7

An organization is planning to move 500 TB of archival data from on-premises to Cloud Storage. The data is not frequently accessed, and the network bandwidth is limited to 100 Mbps. What is the most efficient migration approach?

Accepted Answer

Use Transfer Appliance. Transfer Appliance is a physical device for shipping large amounts of data when bandwidth is low. At 100 Mbps, 500 TB would take over 500 days; Transfer Appliance bypasses network constraints.

Answer

Use gsutil rsync with parallel composite uploads

Answer

Use Migrate for Compute Engine

Answer

Use Storage Transfer Service over the internet

Question 8

A company's BigQuery costs are higher than expected. They run many ad-hoc queries with filters on the 'transaction_date' column and 'customer_id' column. They also have a materialized view that is rarely used. Which combination of actions will MOST effectively reduce query costs?

Accepted Answer

Partition on transaction_date, cluster on customer_id, and drop the unused materialized view. Partitioning by transaction_date reduces scanned data for date filters. Clustering by customer_id further reduces bytes billed for queries filtering on that column. Dropping unused materialized views avoids storage costs.

Answer

Convert to a clustered table on transaction_date and disable caching

Answer

Use flat-rate pricing for all queries and cluster on transaction_date

Answer

Partition on customer_id and use materialized views for all queries

Question 9

A team wants to provide a consistent, low-latency experience for global users accessing static content (images, CSS, JS) hosted on Cloud Storage. They also need to be able to invalidate cached content quickly when updates occur. Which service should they use?

Accepted Answer

Cloud CDN. Cloud CDN caches content at edge locations for low latency. Cache invalidation allows purging updated content, which is essential for static assets.

Answer

Cloud NAT

Answer

Cloud Load Balancing with backend bucket

Answer

Cloud Storage transfer service

Question 10

An application uses Cloud SQL (PostgreSQL) and experiences high connection overhead, often exhausting the max connections limit. The team wants to maintain a pool of persistent connections without modifying application code. Which solution should they implement?

Accepted Answer

Deploy PgBouncer on a Compute Engine instance. PgBouncer is a connection pooler for PostgreSQL that manages a pool of connections, reducing overhead and preventing exhaustion. It can be deployed on Compute Engine or using Cloud SQL Auth Proxy with connection pooling.

Answer

Use Cloud Memorystore as a connection cache

Answer

Increase the max connections flag in Cloud SQL

Answer

Configure Cloud SQL Auth Proxy with max connections

Question 11

A company needs to choose between Cloud Spanner and Firestore for a global inventory application that requires strong consistency and horizontal scaling. The application has a fixed schema with complex joins. Which database is most appropriate?

Accepted Answer

Cloud Spanner. Cloud Spanner is a globally distributed relational database with strong consistency and supports complex joins. Firestore is a NoSQL document database with eventual consistency (strong consistency only within a single document).

Answer

Firestore

Answer

Cloud SQL

Answer

Cloud Bigtable

Question 12

Which Google Cloud service automatically computes the optimal size or tier for underutilized Compute Engine instances and generates recommendations to reduce cost?

Accepted Answer

Recommender (Active Assist). Active Assist includes rightsizing recommendations that analyze VM utilization and suggest appropriate machine types or tiers to reduce cost without sacrificing performance.

Answer

Cloud Monitoring

Answer

Cloud Profiler

Answer

Cost Management

Question 13

A company wants to use BigQuery with a predictable monthly cost, regardless of query volume. They have a steady state of around 500 concurrent slots. Which pricing model should they choose?

Accepted Answer

Slot reservations (flat-rate). BigQuery slot reservations (flat-rate) provide a fixed monthly cost based on reserved slots, suitable for predictable workloads. On-demand pricing charges per query and can vary.

Answer

Sustained use discounts

Answer

Committed use discounts for BigQuery

Answer

On-demand pricing

Question 14

An engineer is designing a Bigtable schema for time-series data consisting of sensor readings. Each sensor emits a reading every second. The access pattern is to retrieve all readings for a specific sensor within a time range. Which row key design will provide the best performance?

Accepted Answer

Use row key: [sensor_id]#[reverse_timestamp]. Bigtable stores rows sorted by key. A row key structured as [sensor_id]#[reverse_timestamp] ensures that all data for a sensor is contiguous, and sorting by reverse timestamp allows recent data to be retrieved first. A single row key per sensor with column qualifiers would cause hotspots and limit scalability.

Answer

Use a single row per sensor with column qualifiers as timestamps

Answer

Use timestamp as the row key and sensor ID as column qualifier

Answer

Use a random prefix to distribute writes evenly

Question 15

A company wants to set a monthly spending limit for their Compute Engine usage and receive alerts when spending exceeds a threshold. Which tool should they use?

Accepted Answer

Cloud Budget alerts. Budget alerts in Cloud Billing allow you to set a spending budget and receive notifications when actual spending exceeds thresholds. They can be scoped to projects or services.

Answer

Cloud Monitoring

Answer

Cloud Logging

Answer

Cloud Armor