10 free Google Professional Cloud Architect practice questions with the correct answer and a full explanation for each, taken from the CertStash pack of 360 questions. Work through them, then open each answer to check your reasoning.
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Question 1
Your company has decided to make a major revision of their API in order to create better experiences for their developers. They need to keep the old version of the API available and deployable, while allowing new customers and testers to try out the new API. They want to keep the same SSL and DNS records in place to serve both APIs.
What should they do?
Show answer and explanation
Correct answer: D. Use separate backend pools for each API path behind the load balancer
Using separate backend pools for each API path behind a single load balancer allows the company to serve both old and new API versions from the same SSL certificate and DNS record. The load balancer can route requests to different backend pools based on the request path, keeping the same endpoint while supporting both API versions simultaneously.
Why the other options are wrong
- A. A new load balancer would require separate DNS/SSL records, contradicting the requirement to keep these unchanged.
- B. Reconfiguring old clients defeats the purpose of maintaining backward compatibility with the same endpoint.
- C. Having the old API forward to the new API would not allow running both versions independently and could cause compatibility issues.
Question 2
Your company plans to migrate a multi-petabyte data set to the cloud. The data set must be available 24hrs a day. Your business analysts have experience only with using a SQL interface.
How should you store the data to optimize it for ease of analysis?
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Correct answer: A. Load data into Google BigQuery
Google BigQuery is a fully managed data warehouse optimized for large-scale analytical queries. It provides SQL interface for business analysts, handles multi-petabyte datasets efficiently, offers 24/7 availability, and is purpose-built for analysis and reporting scenarios like this.
Why the other options are wrong
- B. Cloud SQL is designed for transactional databases, not analytical workloads, and has limitations for multi-petabyte datasets.
- C. Cloud Storage with flat files lacks the query capability and SQL interface needed by business analysts.
- D. Cloud Datastore is a NoSQL document database unsuitable for analytical queries and not optimized for this use case.
Question 3
The operations manager asks you for a list of recommended practices that she should consider when migrating a J2EE application to the cloud.
Which three practices should you recommend? (Choose three.)
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Correct answer: C, D, E
C. Instrument the application with a monitoring tool like Stackdriver Debugger D. Select an automation framework to reliably provision the cloud infrastructure E. Deploy a continuous integration tool with automated testing in a staging environment The three recommended practices are: (C) Instrumenting with monitoring tools like Stackdriver Debugger provides visibility into application performance and debugging; (D) Automation frameworks reliably provision infrastructure consistently; and (E) Continuous integration with automated testing in staging catches errors before production. These address operational excellence, reliability, and quality assurance in cloud migrations.
Why the other options are wrong
- A. Porting to App Engine is an implementation choice that may not fit all J2EE applications and isn't universally recommended for migration strategy.
- B. Cloud Dataflow is for data pipeline processing, not a general recommendation for application migration monitoring needs.
Question 4
A news feed web service has the following code running on Google App Engine. During peak load, users report that they can see news articles they already viewed.
What is the most likely cause of this problem?
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Correct answer: A. The session variable is local to just a single instance
The code stores session data in a local Python dictionary (`sessions = {}`), which exists only in memory on a single App Engine instance. During peak load, Google App Engine automatically scales by creating multiple instances to handle requests. When users are routed to different instances (due to load balancing), their session data is not available on the new instance because each instance has its own separate in-memory dictionary. This causes previously viewed articles to reappear since the viewing history is lost when the user hits a different instance.
Why the other options are wrong
- B. The code does not use Cloud Datastore for session storage; it only uses a local i-emory dictionary, so overwriting in Datastore is not the issue.
- C. The problem is not related to URL caching or API endpoint design; it's a session persistence issue across multiple instances.
- D. HTTP Expires headers control browser caching of responses, not the server-side session persistence problem of tracking viewed articles across instances.
Question 5
An application development team believes their current logging tool will not meet their needs for their new cloud-based product. They want a better tool to capture errors and help them analyze their historical log data. You want to help them find a solution that meets their needs.
What should you do?
Show answer and explanation
Correct answer: C. Help them define their requirements and assess viable logging tools
The best approach is to help the team define their specific requirements and assess viable solutions. This consultative approach ensures the selected tool actually meets their needs for error capture and historical log analysis, rather than immediately prescribing a specific product or assuming the current tool can be fixed.
Why the other options are wrong
- A. Directing them to install Stackdriver immediately skips the requirements assessment phase and may not be the right tool.
- B. Providing generic resources doesn't address their specific problem of finding the right tool for their needs.
- D. Upgrading their current tool assumes it can be fixed, but they've already determined it won't meet their needs.
Question 6
You need to reduce the number of unplanned rollbacks of erroneous production deployments in your company's web hosting platform.
Improvement to the QA/ Test processes accomplished an 80% reduction.
Which additional two approaches can you take to further reduce the rollbacks? (Choose two.)
Show answer and explanation
Correct answer: A, C
A. Introduce a green-blue deployment model C. Fragment the monolithic platform into microservices Blue-green deployment validates the new version on an idle environment before switching traffic, so bad releases are caught early and rollback is just a traffic flip. Microservices shrink the blast radius, so a faulty deploy hits one service, not the whole platform. Together they cut unplanned rollbacks.
Why the other options are wrong
- B. Canary releases help, but dropping the QA environment removes a testing stage and adds risk.
- D. Fewer relational database dependencies doesn't address deployment rollbacks.
- E. Changing database types doesn't reduce deployment-related rollbacks.
Question 7
To reduce costs, the Director of Engineering has required all developers to move their development infrastructure resources from on-premises virtual machines (VMs) to Google Cloud Platform. These resources go through multiple start/stop events during the day and require state to persist. You have been asked to design the process of running a development environment in Google Cloud while providing cost visibility to the finance department.
Which two steps should you take? (Choose two.)
Show answer and explanation
Correct answer: A, D
A. Use the – -no-auto-delete flag on all persistent disks and stop the VM D. Use Google BigQuery billing export and labels to associate cost to groups Using the –no-auto-delete flag (A) preserves persistent disks when stopping VMs, allowing state to persist and VMs to restart without recreating disks. This reduces costs since stopped VMs are cheaper than running ones. Using BigQuery billing export with labels (D) provides cost visibility to the finance department by associating resource usage with developer groups.
Why the other options are wrong
- B. Auto-delete flag terminates persistent disks, losing state that needs to persist.
- C. Labels alone don't provide sufficient cost tracking without the billing export mechanism.
- E. Local SSDs are ephemeral and lost on termination; this doesn't persist state.
- F. Terminating VMs contradicts the requirement to preserve state and enable cos-ffective restart.
Question 8
Your company wants to track whether someone is present in a meeting room reserved for a scheduled meeting. There are 1000 meeting rooms across 5 offices on 3 continents. Each room is equipped with a motion sensor that reports its status every second. The data from the motion detector includes only a sensor ID and several different discrete items of information. Analysts will use this data, together with information about account owners and office locations.
Which database type should you use?
Show answer and explanation
Correct answer: B. NoSQL
Each of 1000 rooms reports every second from offices on 3 continents, and the payload is only a sensor ID plus several discrete items. A NoSQL store absorbs that high, continuous write rate and handles a flexible, sparse schema while scaling horizontally across regions. Analysts can still combine these readings with account owner and office location data at analysis time.
Why the other options are wrong
- A. Flat files are inefficient for 1000 rooms generating continuous data and querying with related datasets.
- C. Relational schemas are rigid and scale vertically, so per-second writes from 1000 global sensors strain them.
- D. Blobstore is for unstructured binary data, not structured sensor readings that need querying and analysis.
Question 9
You set up an autoscaling instance group to serve web traffic for an upcoming launch. After configuring the instance group as a backend service to an HTTP(S) load balancer, you notice that virtual machine (VM) instances are being terminated and re-launched every minute. The instances do not have a public IP address.
You have verified the appropriate web response is coming from each instance using the curl command. You want to ensure the backend is configured correctly.
What should you do?
Show answer and explanation
Correct answer: C. Ensure that a firewall rule exists to allow load balancer health checks to reach the instances in the instance group.
VMs are terminating and relaunching every minute because health checks are failing. Since curl commands work from the instances themselves, the application is responding correctly. The issue is that the load balancer's health check probes cannot reach the instances because a firewall rule is blocking the health check traffic. Allowing health check source traffic (typically from Google's health check IP ranges) to the instances solves this.
Why the other options are wrong
- A. Firewall rules for HTTP/HTTPS to the load balancer don't address the internal health check communication issue.
- B. Public IPs aren't necessary for instances behind a load balancer; this wastes resources and isn't the root cause.
- D. Creating tags with the load balancer name doesn't configure proper health check firewall rules and is incorrectly specified.
Question 10
You write a Python script to connect to Google BigQuery from a Google Compute Engine virtual machine. The script is printing errors that it cannot connect to BigQuery.
What should you do to fix the script?
Show answer and explanation
That was 10 of 360.
The full Google Professional Cloud Architect pack has all 360 questions, each with the answer, the explanation and why the other options are wrong, plus a questions-only copy for timed runs. US$39, paid once, with free monthly updates and a pass-or-your-money-back guarantee.