Blob storage (S3, Azure Blob) in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new bucket in S3.

HLD

s3_client.create_bucket(Bucket=[1])

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

A"my-new-bucket"

Bbucket_name

Ccreate_bucket

DBucket

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name without quotes

Using the method name instead of the bucket name

Using the parameter name as the value

The bucket name must be a string in quotes when creating a new S3 bucket.

2fill in blank

medium

Complete the code to upload a file to Azure Blob Storage.

HLD

blob_client.upload_blob([1], overwrite=True)

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

Adata

Bfile_path

Ccontainer_name

Dblob_name

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the file path instead of file content

Passing container or blob names instead of data

The upload_blob method requires the data content to upload, not the file path or names.

3fill in blank

hard

Fix the error in the code to list blobs in an Azure container.

HLD

blobs_list = container_client.[1]()

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

Alist_blob

Bget_blobs

Cget_blob_list

Dlist_blobs

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names that do not exist

Using singular instead of plural method names

The correct method to list blobs is list_blobs(). Other options are invalid method names.

4fill in blank

hard

Fill both blanks to configure S3 bucket policy for public read access.

HLD

{
  "Version": "2012-10-17",
  "Statement": [{
    "Effect": "[1]",
    "Principal": "*",
    "Action": "s3:GetObject",
    "Resource": "arn:aws:s3:::[2]/*"
  }]
}

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

AAllow

BDeny

Cmy-public-bucket

Dprivate-bucket

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Deny' instead of 'Allow' for Effect

Using wrong bucket name in Resource ARN

To allow public read access, the Effect must be 'Allow' and the Resource must specify the correct bucket name.

5fill in blank

hard

Fill all three blanks to generate a presigned URL for an S3 object.

HLD

url = s3_client.generate_presigned_url(
  ClientMethod='[1]',
  Params={'Bucket': '[2]', 'Key': '[3]'},
  ExpiresIn=3600
)

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

Aget_object

Bmy-secure-bucket

Cfile.txt

Dput_object

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'put_object' instead of 'get_object' for download URLs

Using incorrect bucket or key names

The ClientMethod for generating a presigned URL to download is 'get_object'. The Params must include the bucket and the object key.

Practice

1. What is the main purpose of blob storage services like Amazon S3 or Azure Blob Storage?

easy

A. To manage user identities and permissions

B. To run virtual machines in the cloud

C. To store large files safely and accessibly in the cloud

D. To host websites directly without any storage

Solution

1. Step 1: Understand blob storage function

   Blob storage is designed to save large files like videos, images, and backups in the cloud.

2. Step 2: Compare with other cloud services

   Other services like virtual machines or identity management serve different purposes, not file storage.

3. Final Answer:

   To store large files safely and accessibly in the cloud -> Option C

4. Quick Check:

   Blob storage = large file storage [OK]

Hint: Blob storage is for big files, not computing or identity [OK]

Common Mistakes:

• Confusing blob storage with compute services
• Thinking blob storage manages users
• Assuming blob storage hosts websites directly

2. Which of the following is the correct way to specify a bucket name in Amazon S3?

easy

A. My.bucket.name

B. MyBucketName!

C. my_bucket_name

D. my-bucket-name

Solution

1. Step 1: Review S3 bucket naming rules

   S3 bucket names must be lowercase, can include hyphens, but no underscores or special characters like '!'.

2. Step 2: Check each option

   my-bucket-name uses lowercase letters and hyphens, which is valid. Options A, B, and C are invalid: A has uppercase letters and dots, B has uppercase and '!', C has underscores.

3. Final Answer:

   my-bucket-name -> Option D

4. Quick Check:

   Bucket names use lowercase and hyphens [OK]

Hint: Bucket names: lowercase letters and hyphens only [OK]

Common Mistakes:

• Using uppercase letters in bucket names
• Including underscores or special characters
• Using dots in bucket names

3. Given this AWS CLI command:
aws s3 cp file.txt s3://my-bucket/ --storage-class STANDARD_IA
What does the --storage-class STANDARD_IA option do?

medium

A. Uploads the file to a cheaper, infrequently accessed storage tier

B. Encrypts the file automatically during upload

C. Makes the file publicly accessible

D. Uploads the file with maximum redundancy across regions

Solution

1. Step 1: Understand storage classes in S3

   STANDARD_IA means Standard-Infrequent Access, a cheaper tier for files accessed less often.

2. Step 2: Analyze command effect

   The command uploads file.txt to the bucket using this storage class, saving cost for infrequent access.

3. Final Answer:

   Uploads the file to a cheaper, infrequently accessed storage tier -> Option A

4. Quick Check:

   STANDARD_IA = cheaper, infrequent access [OK]

Hint: STANDARD_IA means cheaper storage for rare access [OK]

Common Mistakes:

• Thinking it encrypts the file
• Assuming it makes file public
• Confusing with multi-region redundancy

4. You try to upload a file to Azure Blob Storage but get an error saying the container name is invalid. Which of these is the most likely cause?

medium

A. The container name contains uppercase letters

B. The file size is too large

C. The storage account is in the wrong region

D. The file name has spaces

Solution

1. Step 1: Recall Azure container naming rules

   Container names must be lowercase letters and numbers only, no uppercase letters allowed.

2. Step 2: Match error cause

   An invalid container name error usually means the name breaks these rules, such as having uppercase letters.

3. Final Answer:

   The container name contains uppercase letters -> Option A

4. Quick Check:

   Azure container names must be lowercase [OK]

Hint: Azure containers must be lowercase, no uppercase letters [OK]

Common Mistakes:

• Blaming file size for container name errors
• Confusing region with naming rules
• Thinking file name affects container name

5. You want to store backup files in Amazon S3 with minimal cost but still need quick access sometimes. Which combination of settings is best?

hard

A. Use STANDARD storage class and enable public access for easy retrieval

B. Use STANDARD_IA storage class with lifecycle rule to move files to GLACIER after 30 days

C. Use GLACIER storage class for all files with no lifecycle rules

D. Use REDUCED_REDUNDANCY storage class and no lifecycle rules

Solution

1. Step 1: Understand storage classes and lifecycle

   STANDARD_IA offers cheaper storage with quick access. GLACIER is very cheap but slow to retrieve.

2. Step 2: Analyze cost and access needs

   Using STANDARD_IA first allows quick access. Moving to GLACIER after 30 days saves cost for older backups.

3. Step 3: Evaluate other options

   GLACIER only delays access too much. STANDARD is costly. REDUCED_REDUNDANCY is deprecated and less reliable.

4. Final Answer:

   Use STANDARD_IA storage class with lifecycle rule to move files to GLACIER after 30 days -> Option B

5. Quick Check:

   STANDARD_IA + lifecycle to GLACIER = cost + access balance [OK]

Hint: Start with STANDARD_IA, then archive to GLACIER for cost savings [OK]

Common Mistakes:

• Choosing GLACIER only and ignoring access speed
• Enabling public access unnecessarily
• Using deprecated REDUCED_REDUNDANCY class