📖 What is AWS Lambda?
AWS Lambda is a serverless compute service that executes code in response to events without requiring server management. Developers upload code as functions, and Lambda automatically scales and manages the infrastructure. Billing is based on the number of requests and execution duration, offering a pay-per-use model.
"Lambda’s event-driven architecture is crucial. Common triggers include API Gateway, S3, and DynamoDB. Understand the concept of execution roles and the limitations of execution time and memory. Exam questions often test understanding of Lambda’s integration with other AWS services."
📚 Certification: AWS Certified Cloud Practitioner (CLF-C02)
🔑 What are the Key Concepts of AWS Lambda?
- ▸ Lambda functions are triggered by events, eliminating the need for constant server monitoring and scaling; understand common event sources like S3 and API Gateway.
- ▸ Execution roles define the permissions a Lambda function has to access other AWS services, crucial for security and functionality.
- ▸ Lambda’s pay-per-use model bills based on requests and execution duration, making it cost-effective for intermittent or unpredictable workloads.
- ▸ Lambda has limitations on execution time (max 15 minutes) and memory allocation (up to 10GB), impacting suitability for certain tasks.
- ▸ Serverless doesn’t mean ‘no servers’ – AWS manages the servers, but developers focus solely on code, simplifying deployment and operations.
🎯 How does AWS Lambda appear on the CLF-C02 Exam?
You may be asked to identify the most cost-effective compute service for processing images uploaded to an S3 bucket, considering infrequent usage patterns.
A scenario might describe a web application needing a backend API; expect questions about using API Gateway to trigger Lambda functions for request handling.
Expect questions about troubleshooting a Lambda function that fails to access an S3 bucket – focus on verifying the execution role permissions.
❓ Frequently Asked Questions
When would I choose Lambda over EC2?
Choose Lambda for event-driven, stateless applications with variable workloads. EC2 is better for long-running processes or applications requiring full OS access and control.
What are 'layers' in Lambda and why are they useful?
Layers allow you to package and share common code (libraries, dependencies) across multiple Lambda functions, reducing code duplication and simplifying updates.
How does Lambda handle concurrency and scaling?
Lambda automatically scales by creating multiple instances of your function to handle concurrent requests. You can configure reserved concurrency to limit scaling or provisioned concurrency for predictable startup times.