Backend services and backend buckets in GCP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a backend bucket with a specified Cloud Storage bucket name.

GCP

gcloud compute backend-buckets create my-backend-bucket --gcs-bucket-name=[1]

Drag options to blanks, or click blank then click option'

Astorage-bucket-123

Bmy-backend-bucket

Cbackend-bucket-1

Dmy-storage-bucket

Attempts:

3 left

💡 Hint

Common Mistakes

Using the backend bucket name instead of the Cloud Storage bucket name.

Confusing the backend bucket name with the storage bucket name.

The --gcs-bucket-name flag requires the name of the Cloud Storage bucket to use as the backend bucket.

2fill in blank

medium

Complete the code to add a backend bucket to a URL map.

GCP

gcloud compute url-maps add-backend-bucket my-url-map --backend-bucket-name=[1]

Drag options to blanks, or click blank then click option'

Amy-backend-bucket

Bmy-url-map

Cdefault-backend

Dbucket-backend-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using the URL map name instead of the backend bucket name.

Confusing backend bucket with backend service.

The --backend-bucket-name flag requires the name of the backend bucket to add to the URL map.

3fill in blank

hard

Fix the error in the command to create a backend bucket with a Cloud Storage bucket name.

GCP

gcloud compute backend-buckets create my-backend-bucket --[1]=my-storage-bucket

Drag options to blanks, or click blank then click option'

Agcs-bucket-name

Bbucket-name

Cbackend-bucket

Dstorage-bucket

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect flag names like --backend-bucket.

Confusing backend bucket creation with backend service creation.

To create a backend bucket with a Cloud Storage bucket, use the --gcs-bucket-name flag with the bucket name.

4fill in blank

hard

Fill both blanks to configure a backend bucket with Cloud CDN enabled and a custom description.

GCP

gcloud compute backend-buckets create my-backend-bucket --gcs-bucket-name=[1] --enable-cdn=[2] --description="Static content bucket"

Drag options to blanks, or click blank then click option'

Amy-static-bucket

Btrue

Cfalse

Dmy-backend-bucket

Attempts:

3 left

💡 Hint

Common Mistakes

Setting --enable-cdn to false when CDN is desired.

Using backend bucket name instead of Cloud Storage bucket name.

The --gcs-bucket-name flag needs the Cloud Storage bucket name, and --enable-cdn should be set to true to enable CDN.

5fill in blank

hard

Fill all three blanks to create a URL map that routes requests to a backend bucket with a host rule.

GCP

gcloud compute url-maps create my-url-map --default-service=[1] && gcloud compute url-maps add-host-rule my-url-map --hosts=[2] --path-matcher-name=[3]

Drag options to blanks, or click blank then click option'

Amy-backend-bucket

B"example.com"

Cdefault

Ddefault-backend-service

Attempts:

3 left

💡 Hint

Common Mistakes

Using backend service name instead of backend bucket.

Not quoting the host name.

Using incorrect path matcher names.

The URL map uses the backend bucket as default, sets the host to example.com, and names the path matcher default.

Practice

1. What is the main purpose of a backend service in Google Cloud Load Balancing?

easy

A. To manage user authentication and authorization

B. To connect the load balancer to server groups for dynamic content

C. To monitor network traffic between regions

D. To store static files like images and videos

Solution

1. Step 1: Understand backend service role

   A backend service connects the load balancer to server groups that handle dynamic content like web apps.

2. Step 2: Differentiate from backend bucket

   Backend buckets connect to Cloud Storage for static content, not dynamic server groups.

3. Final Answer:

   To connect the load balancer to server groups for dynamic content -> Option B

4. Quick Check:

   Backend service = dynamic content connection [OK]

Hint: Backend service = dynamic servers, backend bucket = static storage [OK]

Common Mistakes:

• Confusing backend service with backend bucket
• Thinking backend service stores static files
• Assuming backend service manages authentication

2. Which of the following is the correct way to specify a backend bucket in a Google Cloud Load Balancer configuration?

easy

A. "backendService": "projects/my-project/global/backendBuckets/my-bucket"

B. "backendService": "projects/my-project/global/backendServices/my-service"

C. "backendBucket": "projects/my-project/global/backendServices/my-service"

D. "backendBucket": "projects/my-project/global/backendBuckets/my-bucket"

Solution

1. Step 1: Identify correct field for backend bucket

   The field to specify a backend bucket is "backendBucket" with the bucket's full path.

2. Step 2: Verify resource path matches backend bucket

   The resource path must include "backendBuckets" for a bucket, not "backendServices".

3. Final Answer:

   "backendBucket": "projects/my-project/global/backendBuckets/my-bucket" -> Option D

4. Quick Check:

   backendBucket field + backendBuckets path = correct [OK]

Hint: backendBucket key + backendBuckets path = backend bucket config [OK]

Common Mistakes:

• Using backendService key for backend bucket
• Mixing backendServices and backendBuckets in path
• Incorrect resource path format

3. Given this backend service configuration snippet, what will happen if the health check fails for all instances in the backend?

{
  "name": "my-backend-service",
  "healthChecks": ["projects/my-project/global/healthChecks/my-check"],
  "backends": [{"group": "projects/my-project/zones/us-central1-a/instanceGroups/my-group"}]
}

medium

A. The load balancer will stop sending traffic to this backend service

B. The load balancer will continue sending traffic to the backend service regardless

C. The load balancer will delete the backend service automatically

D. The load balancer will redirect traffic to the backend bucket

Solution

1. Step 1: Understand health check role

   Health checks monitor backend instances. If all fail, the backend is unhealthy.

2. Step 2: Effect on load balancer traffic

   Load balancer stops sending traffic to unhealthy backends to avoid errors.

3. Final Answer:

   The load balancer will stop sending traffic to this backend service -> Option A

4. Quick Check:

   Health check fail = no traffic sent [OK]

Hint: Failed health checks stop traffic to backend service [OK]

Common Mistakes:

• Assuming traffic continues despite health check failure
• Thinking backend service is deleted automatically
• Confusing backend service with backend bucket behavior

4. You configured a backend bucket for your load balancer but users report 403 errors when accessing static content. What is the most likely cause?

medium

A. The load balancer is not attached to any instance group

B. The backend service health check is failing

C. The backend bucket is missing the correct Cloud Storage permissions

D. The backend bucket name is misspelled in the load balancer config

Solution

1. Step 1: Check backend bucket access

   Backend buckets serve static content from Cloud Storage, which requires proper permissions.

2. Step 2: Identify cause of 403 errors

   Missing or incorrect permissions cause 403 errors because content cannot be accessed.

3. Final Answer:

   The backend bucket is missing the correct Cloud Storage permissions -> Option C

4. Quick Check:

   Missing permissions cause 403 on static content [OK]

Hint: 403 on static content usually means permission issues [OK]

Common Mistakes:

• Confusing backend bucket with backend service health checks
• Assuming instance groups affect backend buckets
• Overlooking spelling errors as cause

5. You want to serve a website with both dynamic content from Compute Engine instances and static content from Cloud Storage using a single HTTP(S) load balancer. How should you configure the backend services and backend buckets?

hard

A. Create a backend service for the instance group and a backend bucket for the Cloud Storage bucket, then configure URL map to route requests accordingly

B. Create only a backend bucket and upload dynamic content to Cloud Storage

C. Create multiple backend services for both static and dynamic content and ignore backend buckets

D. Use a backend service for static content and a backend bucket for dynamic content

Solution

1. Step 1: Understand content types and backends

   Dynamic content requires backend services connected to instance groups; static content uses backend buckets linked to Cloud Storage.

2. Step 2: Configure URL map routing

   Use URL map rules to route requests to backend service or backend bucket based on URL paths.

3. Final Answer:

   Create a backend service for the instance group and a backend bucket for the Cloud Storage bucket, then configure URL map to route requests accordingly -> Option A

4. Quick Check:

   Dynamic = backend service, static = backend bucket, route with URL map [OK]

Hint: Use URL map to route dynamic to backend service, static to backend bucket [OK]

Common Mistakes:

• Trying to serve dynamic content from backend bucket
• Ignoring URL map routing configuration
• Using backend service for static content