Right-sizing resources in AWS - Mini Project: Build & Apply

Right-sizing AWS EC2 Instances

📖 Scenario: You are managing cloud resources for a small company. They have several AWS EC2 instances running, but some are too large and costly for their needs. Your task is to help them identify and right-size these instances to save money while keeping performance.

🎯 Goal: Build a simple AWS resource configuration that lists EC2 instances with their current sizes and then creates a recommended smaller instance type for right-sizing.

📋 What You'll Learn

Create a dictionary of EC2 instances with their current instance types

Add a configuration variable for the maximum allowed instance size

Write logic to recommend a smaller instance type if the current one is larger than allowed

Output the final dictionary with instance IDs and their recommended instance types

💡 Why This Matters

🌍 Real World

Cloud engineers often need to optimize resource usage to reduce costs and improve efficiency. Right-sizing instances is a common task to avoid paying for more capacity than needed.

💼 Career

Understanding how to analyze and recommend resource sizes is valuable for roles like Cloud Engineer, DevOps Engineer, and Infrastructure Architect.

1

Create EC2 instances dictionary

Create a dictionary called ec2_instances with these exact entries: 'i-12345': 't3.large', 'i-67890': 't3.xlarge', 'i-abcde': 't2.medium'

AWS

# Create the ec2_instances dictionary with instance IDs and types
# Your code here

Hint

Use a Python dictionary with instance IDs as keys and instance types as values.

2

Add maximum allowed instance size

Add a variable called max_instance_size and set it to the string 't3.large'

AWS

ec2_instances = {'i-12345': 't3.large', 'i-67890': 't3.xlarge', 'i-abcde': 't2.medium'}
# Define max_instance_size variable
# Your code here

Hint

This variable will help decide if an instance is too large.

3

Write right-sizing recommendation logic

Create a dictionary called recommended_sizes. Use a for loop with variables instance_id and instance_type to iterate over ec2_instances.items(). For each instance, if instance_type is larger than max_instance_size, set its recommended size to max_instance_size, otherwise keep the current instance_type.

AWS

ec2_instances = {'i-12345': 't3.large', 'i-67890': 't3.xlarge', 'i-abcde': 't2.medium'}
max_instance_size = 't3.large'
# Create recommended_sizes dictionary with right-sizing logic
# Your code here

Hint

Use a dictionary and a for loop to compare instance types and assign recommended sizes.

4

Complete with final recommended sizes dictionary

Add a final line that creates a variable called final_recommendations and sets it equal to recommended_sizes

AWS

ec2_instances = {'i-12345': 't3.large', 'i-67890': 't3.xlarge', 'i-abcde': 't2.medium'}
max_instance_size = 't3.large'

# Define an order for instance sizes to compare them properly
instance_size_order = ['t2.medium', 't3.large', 't3.xlarge']

recommended_sizes = {}
for instance_id, instance_type in ec2_instances.items():
    if instance_size_order.index(instance_type) > instance_size_order.index(max_instance_size):
        recommended_sizes[instance_id] = max_instance_size
    else:
        recommended_sizes[instance_id] = instance_type
# Set final_recommendations equal to recommended_sizes
# Your code here

Hint

This final variable holds the right-sizing recommendations.

Practice

1. What does right-sizing mean in cloud resource management?

easy

A. Always picking the largest resource available

B. Choosing the best resource size to match your actual needs

C. Using resources without monitoring their usage

D. Ignoring cost and focusing only on performance

Solution

1. Step 1: Understand the meaning of right-sizing

   Right-sizing means selecting resources that fit your workload requirements without waste.

2. Step 2: Compare options to definition

   Only Choosing the best resource size to match your actual needs matches the idea of matching resource size to actual needs.

3. Final Answer:

   Choosing the best resource size to match your actual needs -> Option B

4. Quick Check:

   Right-sizing = best fit resource size [OK]

Hint: Right-sizing means matching size to need, not max or ignore usage [OK]

Common Mistakes:

• Thinking right-sizing means always picking the biggest resource
• Ignoring usage data when choosing resources
• Confusing right-sizing with ignoring costs

2. Which AWS service helps you analyze resource usage to right-size your EC2 instances?

easy

A. AWS CloudTrail

B. AWS Cost Explorer

C. AWS Trusted Advisor

D. AWS Lambda

Solution

1. Step 1: Identify AWS services for resource optimization

   AWS Trusted Advisor provides recommendations including right-sizing EC2 instances.

2. Step 2: Eliminate unrelated services

   CloudTrail logs API calls, Cost Explorer shows costs, Lambda runs code; only Trusted Advisor analyzes usage for right-sizing.

3. Final Answer:

   AWS Trusted Advisor -> Option C

4. Quick Check:

   Trusted Advisor = right-sizing help [OK]

Hint: Trusted Advisor gives right-sizing tips for EC2 [OK]

Common Mistakes:

• Confusing CloudTrail with usage analysis
• Thinking Cost Explorer directly suggests right-sizing
• Selecting Lambda which is unrelated to resource sizing

3. You have an EC2 instance running at 10% CPU most of the time. What is the likely output of a right-sizing recommendation script?

medium

A. Recommend upgrading to a larger instance type

B. Recommend no change to instance size

C. Recommend terminating the instance

D. Recommend downgrading to a smaller instance type

Solution

1. Step 1: Analyze CPU usage data

   10% CPU usage means the instance is underutilized and likely oversized.

2. Step 2: Determine right-sizing action

   Underutilization suggests downgrading to a smaller instance to save cost.

3. Final Answer:

   Recommend downgrading to a smaller instance type -> Option D

4. Quick Check:

   Low CPU usage = downsize instance [OK]

Hint: Low CPU means smaller instance recommended [OK]

Common Mistakes:

• Choosing to upgrade when usage is low
• Thinking no change is needed despite low usage
• Confusing termination with right-sizing

4. A user tries to right-size an EC2 instance but gets an error: "Instance type not supported in this AZ." What is the best fix?

medium

A. Change the instance type to one supported in the availability zone

B. Ignore the error and try again

C. Terminate the instance immediately

D. Switch to a different AWS region without checking

Solution

1. Step 1: Understand the error context

   The error means the chosen instance type is not available in the current availability zone.

2. Step 2: Apply correct fix

   Selecting an instance type supported in the same availability zone resolves the error.

3. Final Answer:

   Change the instance type to one supported in the availability zone -> Option A

4. Quick Check:

   Unsupported instance type in AZ = pick supported type [OK]

Hint: Pick instance types supported in your AZ [OK]

Common Mistakes:

• Ignoring the error and retrying
• Terminating instance without fixing
• Switching regions without checking availability

5. You manage a fleet of EC2 instances with varying CPU usage. Which approach best applies right-sizing to reduce costs without hurting performance?

hard

A. Start with smallest instance types, monitor usage, then scale up as needed

B. Always pick the largest instance type to avoid performance issues

C. Randomly change instance types monthly without monitoring

D. Terminate all instances and switch to on-demand only

Solution

1. Step 1: Understand right-sizing best practice

   Right-sizing means starting small and adjusting based on real usage data to avoid waste.

2. Step 2: Evaluate options for cost and performance balance

   Start with smallest instance types, monitor usage, then scale up as needed follows best practice by starting small, monitoring, and scaling up only if needed.

3. Final Answer:

   Start with smallest instance types, monitor usage, then scale up as needed -> Option A

4. Quick Check:

   Start small + monitor + scale = right-sizing [OK]

Hint: Start small, watch usage, then adjust size [OK]

Common Mistakes:

• Always picking largest instance wastes money
• Changing types randomly causes instability
• Terminating all instances ignores workload needs