AWS Lambda Fundamentals

Introduction

AWS Lambda is a serverless compute service that runs your code in response to events and automatically manages the underlying compute resources for you. It enables you to execute code without provisioning or managing servers, making it perfect for building applications that respond quickly to new information.

What is AWS Lambda?

AWS Lambda lets you run code without provisioning or managing servers. You can run your code in response to events such as changes in data or system state, or in response to HTTP requests. Lambda automatically scales your applications by running the code in response to each trigger.

Key Concepts

• **Function**: A Lambda function is your code that performs a specific task.
• **Event Source**: An event source is a service that can trigger your Lambda function, such as S3 or API Gateway.
• **Execution Role**: A role that grants your Lambda function permissions to access other AWS resources.
• **Timeout**: The maximum amount of time that your function can run before it is forcibly terminated (default is 3 seconds, max is 15 minutes).

Creating a Lambda Function

1. Log in to the AWS Management Console.
2. Navigate to the Lambda service.
3. Click on "Create Function".
4. Select "Author from scratch".
5. Specify a function name and select a runtime environment.
6. Set up permissions and click "Create Function".
7. Add your code in the inline editor or upload a .zip file.
8. Click on "Deploy" to save the changes.

def lambda_handler(event, context):
    return {
        'statusCode': 200,
        'body': 'Hello, World!'
    }
            

Best Practices

• Keep your functions small and focused on a single purpose.
• Use environment variables for configuration values.
• Monitor your functions with AWS CloudWatch.
• Set appropriate timeout values to avoid unnecessary costs.
• Use versioning to manage changes and rollback if necessary.

FAQ

Flowchart of Creating a Lambda Function

graph TD;
    A[Start] --> B[Log in to AWS Management Console];
    B --> C[Navigate to Lambda Service];
    C --> D[Create Function];
    D --> E[Author from scratch];
    E --> F[Specify Function Name];
    F --> G[Set Permissions];
    G --> H[Create Function];
    H --> I[Add Code];
    I --> J[Deploy];
    J --> K[End];