Lambda function concept in AWS - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

What happens when a Lambda function exceeds its configured timeout?

You have set a Lambda function timeout to 10 seconds. The function runs longer than 10 seconds. What is the result?

A The function restarts automatically and runs again from the start.

B The function continues running until it finishes, ignoring the timeout.

C The function pauses and resumes after the timeout period.

D The function is forcibly stopped and an error is returned.

💡 Hint

Think about how time limits protect resources in cloud functions.

When a Lambda function runs longer than its configured timeout, AWS forcibly stops it and returns a timeout error. This prevents runaway costs and resource use.

❓ Architecture

intermediate

Which AWS service is best to trigger a Lambda function on a schedule?

You want to run a Lambda function every day at 8 AM automatically. Which AWS service should you use to trigger it?

A Amazon S3

B Amazon EventBridge (CloudWatch Events)

C AWS IAM

D Amazon DynamoDB

💡 Hint

Think about services that can schedule tasks or events.

Amazon EventBridge (formerly CloudWatch Events) can create rules to trigger Lambda functions on schedules like cron expressions.

❓ security

advanced

What is the best practice for Lambda function permissions to access an S3 bucket?

You want your Lambda function to read files from a specific S3 bucket. Which approach follows the best security practice?

A Attach an IAM role to the Lambda function with permissions limited to read only the specific S3 bucket.

B Embed AWS access keys with full S3 access inside the Lambda function code.

C Grant public read access to the S3 bucket so Lambda can access it without permissions.

D Use the Lambda function's default execution role without modifying permissions.

💡 Hint

Consider the principle of least privilege and secure credential management.

Assigning a specific IAM role with limited permissions to the Lambda function is secure and follows best practices. Embedding keys or making buckets public is insecure.

❓ Configuration

advanced

What is the effect of increasing the memory allocation of a Lambda function?

You increase the memory setting of a Lambda function from 128 MB to 1024 MB. What changes occur?

A The CPU power allocated to the function increases proportionally, potentially reducing execution time.

B Only the memory increases; CPU power and execution time remain the same.

C The function's timeout automatically increases to allow longer execution.

D The function's network bandwidth decreases to balance resource usage.

💡 Hint

Think about how AWS bundles CPU with memory for Lambda functions.

In AWS Lambda, CPU power scales with memory allocation. Increasing memory also increases CPU, which can speed up execution.

✅ Best Practice

expert

How should you handle environment variables in Lambda for sensitive data?

You need to store database passwords for your Lambda function securely. What is the best practice?

A Hardcode the passwords inside the Lambda function code for faster access.

B Store the passwords as plain text environment variables in the Lambda configuration.

C Use AWS Secrets Manager or AWS Systems Manager Parameter Store with encryption, and reference them in the Lambda function.

D Send the passwords as part of the Lambda event payload each time it runs.

💡 Hint

Consider secure storage and retrieval of secrets in AWS.

Using AWS Secrets Manager or Parameter Store with encryption is the best practice to keep sensitive data secure and separate from code.