RDS pricing considerations in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the RDS instance class for cost estimation.

AWS

rds_instance = {"DBInstanceClass": "[1]"}

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

Adb.t3.micro

Bdb.large

Cdb.xlarge

Ddb.m5.24xlarge

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting a large instance class increases cost unnecessarily.

Using an instance class not supported by RDS.

The db.t3.micro instance class is a low-cost option suitable for small workloads, helping to minimize RDS costs.

2fill in blank

medium

Complete the code to enable Multi-AZ deployment for high availability, which affects pricing.

AWS

rds_config = {"MultiAZ": [1]

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

A"true"

B"false"

Ctrue

DFalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using string values instead of boolean.

Disabling Multi-AZ when high availability is needed.

Setting MultiAZ to true enables high availability but increases cost.

3fill in blank

hard

Fix the error in the storage type to select a cost-effective option.

AWS

storage_config = {"StorageType": "[1]"}

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

Astandard

Bgp3

Cio1

Dgp2

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing io1 which is expensive and high performance.

Using gp2 or gp3 which cost more than standard.

The standard storage type is the most cost-effective but slower option compared to gp2 or io1.

4fill in blank

hard

Fill both blanks to configure backup retention and storage allocation for cost control.

AWS

backup_config = {"BackupRetentionPeriod": [1], "AllocatedStorage": [2]

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

A7

B30

C20

D100

Attempts:

3 left

💡 Hint

Common Mistakes

Setting backup retention too high increases cost.

Allocating excessive storage wastes money.

Setting BackupRetentionPeriod to 7 days limits backup costs. Allocating 20 GB storage keeps storage costs low.

5fill in blank

hard

Fill all three blanks to configure RDS instance with cost-saving options: instance class, storage type, and Multi-AZ.

AWS

rds_settings = {"DBInstanceClass": "[1]", "StorageType": "[2]", "MultiAZ": [3]

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

Adb.t3.micro

Btrue

Cstandard

Ddb.m5.large

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting large instance classes or expensive storage.

Using string 'true' instead of boolean true for MultiAZ.

Using db.t3.micro and standard storage reduces costs. Setting MultiAZ to true adds availability but increases price.

Practice

1. Which factor directly affects the hourly cost of an AWS RDS instance?

easy

A. The number of tables in the database

B. The instance size (e.g., db.t3.medium vs db.m5.large)

C. The number of users connected

D. The database engine version

Solution

1. Step 1: Understand RDS pricing components

   RDS pricing depends on instance size, storage, backups, and deployment options, not on users or tables.

2. Step 2: Identify the factor affecting hourly cost

   The instance size determines the compute capacity and directly affects the hourly price.

3. Final Answer:

   The instance size (e.g., db.t3.medium vs db.m5.large) -> Option B

4. Quick Check:

   Instance size = hourly cost [OK]

Hint: Instance size controls hourly cost, not users or tables [OK]

Common Mistakes:

• Confusing number of users with cost
• Thinking database engine version affects hourly price
• Assuming number of tables changes cost

2. Which storage type option is valid when configuring AWS RDS storage?

easy

A. Magnetic

B. NVMe

C. SSD General Purpose (gp3)

D. Tape Drive

Solution

1. Step 1: Review valid RDS storage types

   AWS RDS supports SSD General Purpose (gp2/gp3), Provisioned IOPS SSD, and Magnetic (deprecated).

2. Step 2: Identify the valid current option

   SSD General Purpose (gp3) is a valid and recommended storage type for RDS.

3. Final Answer:

   SSD General Purpose (gp3) -> Option C

4. Quick Check:

   gp3 is valid RDS storage [OK]

Hint: Choose gp3 for modern RDS SSD storage [OK]

Common Mistakes:

• Selecting deprecated or unsupported storage types
• Confusing tape or NVMe with RDS storage
• Assuming Magnetic is still recommended

3. Given an RDS instance with 100 GB of gp3 storage and 7 days backup retention, which factor will increase the monthly cost the most?

medium

A. Switching database engine from MySQL to PostgreSQL

B. Increasing backup retention from 7 to 35 days

C. Changing instance type from db.t3.medium to db.t3.small

D. Increasing storage from 100 GB to 200 GB

Solution

1. Step 1: Analyze cost impact of backup retention

   Backup storage beyond allocated free backup size adds cost, but increasing retention from 7 to 35 days may add moderate cost.

2. Step 2: Analyze cost impact of storage increase

   Doubling storage from 100 GB to 200 GB doubles storage cost, which is a significant monthly cost increase.

3. Step 3: Analyze instance type and engine changes

   Changing to smaller instance reduces cost; engine change does not affect pricing directly.

4. Final Answer:

   Increasing storage from 100 GB to 200 GB -> Option D

5. Quick Check:

   Storage size increase = biggest cost rise [OK]

Hint: Storage size impacts monthly cost more than backup days [OK]

Common Mistakes:

• Assuming backup retention always costs more
• Thinking smaller instance increases cost
• Believing engine type changes price

4. You configured an RDS instance with Multi-AZ deployment but forgot to enable automated backups. What pricing issue will occur?

medium

A. You will be charged for Multi-AZ but no backup storage cost

B. You will be charged for backup storage even if backups are disabled

C. You will not be charged for Multi-AZ deployment

D. You will be charged for backup storage only if manual snapshots exist

Solution

1. Step 1: Understand Multi-AZ pricing

   Multi-AZ doubles instance cost because a standby instance runs in another zone.

2. Step 2: Understand backup storage pricing

   Automated backups must be enabled to incur backup storage charges; if disabled, no backup storage cost applies.

3. Final Answer:

   You will be charged for Multi-AZ but no backup storage cost -> Option A

4. Quick Check:

   Multi-AZ charges apply; backups disabled means no backup cost [OK]

Hint: Multi-AZ costs apply even if backups are off [OK]

Common Mistakes:

• Assuming backup storage cost applies without backups enabled
• Thinking Multi-AZ is free
• Confusing manual snapshots with automated backups

5. You want to minimize AWS RDS costs for a development environment that requires low latency and high availability. Which combination is best?

hard

A. Use a small instance with Multi-AZ deployment and gp3 storage

B. Use a medium instance with Multi-AZ deployment and Magnetic storage

C. Use a small instance with Single-AZ deployment and gp3 storage

D. Use a large instance with Single-AZ deployment and gp3 storage

Solution

1. Step 1: Identify cost and availability needs

   Low latency and high availability require Multi-AZ deployment and sufficient instance size.

2. Step 2: Evaluate storage and instance size

   gp3 storage is cost-effective and performant; small instance reduces cost while Multi-AZ ensures availability.

3. Step 3: Compare options

   Use a small instance with Multi-AZ deployment and gp3 storage balances cost (small instance), availability (Multi-AZ), and performance (gp3 storage).

4. Final Answer:

   Use a small instance with Multi-AZ deployment and gp3 storage -> Option A

5. Quick Check:

   Small + Multi-AZ + gp3 = cost-effective high availability [OK]

Hint: Multi-AZ + small instance + gp3 balances cost and availability [OK]

Common Mistakes:

• Choosing Magnetic storage which is slower and deprecated
• Ignoring Multi-AZ for high availability
• Picking large instance unnecessarily increasing cost