Backend services and backend buckets in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

How does a backend bucket serve content in GCP?

In Google Cloud Platform, a backend bucket is used with a load balancer to serve static content. What happens when a user requests a file that does not exist in the backend bucket?

A The load balancer returns a 404 Not Found error to the user.

B The load balancer redirects the user to the homepage of the backend bucket.

C The load balancer automatically creates the missing file with default content.

D The load balancer retries the request to other backend buckets automatically.

💡 Hint

Think about what happens when a file is missing in a static content server.

If a requested file is not found in the backend bucket, the load balancer returns a 404 Not Found error because the content does not exist. It does not redirect, create files, or retry automatically.

❓ Architecture

intermediate

Choosing backend services vs backend buckets for a web app

You are designing a web application on GCP that serves both dynamic content from Compute Engine instances and static content like images and CSS files. Which architecture best uses backend services and backend buckets?

A Use separate load balancers for backend services and backend buckets without combining them.

B Use a backend service for Compute Engine instances to serve dynamic content and a backend bucket for static content, both behind the same HTTP(S) load balancer.

C Use backend services for static content and backend buckets for dynamic content.

D Use only backend buckets for all content because they are simpler to manage.

💡 Hint

Think about which backend type is optimized for dynamic vs static content.

Backend services are designed to manage dynamic content from Compute Engine instances or other backends, while backend buckets are optimized for serving static content from Cloud Storage. Combining both behind one HTTP(S) load balancer is best practice.

❓ security

advanced

Securing access to backend buckets

You want to restrict access to a backend bucket so only requests coming through your load balancer are allowed. Which method achieves this?

A Disable authentication on the load balancer to allow direct access to the bucket.

B Set the backend bucket to public so anyone can access it without restrictions.

C Configure signed URLs or signed cookies on the backend bucket and require the load balancer to use them.

D Use firewall rules on the backend bucket to block all IP addresses except the load balancer.

💡 Hint

Think about how Cloud Storage controls access to objects.

Signed URLs or signed cookies allow controlled access to backend buckets through the load balancer. Public buckets allow open access, and firewall rules do not apply to Cloud Storage buckets.

❓ Configuration

advanced

Configuring a backend service with health checks

You have a backend service with multiple Compute Engine instances. You want to ensure traffic is only sent to healthy instances. Which configuration is required?

A Set the backend service to use a static IP address for all instances.

B Disable health checks and rely on instance auto-healing only.

C Configure the backend service to ignore instance health and send traffic to all instances equally.

D Attach a health check to the backend service that periodically probes each instance's health endpoint.

💡 Hint

Think about how load balancers detect unhealthy instances.

Health checks allow the backend service to monitor instance health and route traffic only to healthy instances. Ignoring health or disabling checks risks sending traffic to unhealthy instances.

✅ Best Practice

expert

Optimizing cache behavior for backend buckets in GCP

You want to optimize performance and reduce costs by caching static content served from a backend bucket behind a global HTTP(S) load balancer. Which approach follows best practices?

A Set Cache-Control headers on objects in the Cloud Storage bucket and enable Cloud CDN on the backend bucket.

B Disable caching on the backend bucket to always serve fresh content.

C Configure the load balancer to bypass Cloud CDN and fetch directly from the backend bucket every time.

D Use backend services instead of backend buckets to enable caching automatically.

💡 Hint

Consider how HTTP caching works with Cloud CDN and backend buckets.

Setting Cache-Control headers on objects and enabling Cloud CDN on the backend bucket allows caching at the edge, improving performance and reducing backend load. Disabling caching or bypassing CDN reduces these benefits.