Understanding AWS Lambda Architecture

1. Introduction

Goal of the Tutorial:
This tutorial aims to provide a comprehensive understanding of the architecture of AWS Lambda, a serverless computing service provided by Amazon Web Services.

Learning Outcomes:
By the end of this tutorial, you will understand the structure and components of AWS Lambda service, how they interact with each other and how to effectively use them in your applications.

Prerequisites:
- Basic knowledge of Amazon Web Services (AWS)
- Familiarity with JavaScript or Python, as code examples will be provided in these languages.

2. Step-by-Step Guide

AWS Lambda is a part of AWS's serverless offerings. It executes your code in response to events such as a change to data in an Amazon S3 bucket or a change in an Amazon DynamoDB table.

Components of AWS Lambda:
- Event Source: This is the entity that publishes events. AWS services like Amazon S3, Amazon DynamoDB can be event sources.
- Lambda Function: The code you run on AWS Lambda in response to event triggers.
- Event Source Mapping: This is the AWS Lambda resource that reads items from the stream or queue and triggers the function.
- Log Streams: AWS Lambda automatically monitors functions on your behalf and sends function logs to Amazon CloudWatch.

3. Code Examples

Example 1: Creating a Lambda Function

import json
def lambda_handler(event, context):
    print("Event received: " + json.dumps(event, indent=2))
    return {
        'statusCode': 200,
        'body': json.dumps('Hello from Lambda!')
    }

• lambda_handler is the entry point for your Lambda function.
• event is the input to your Lambda function which contains an event document that AWS Lambda sends to your function.
• context contains runtime information.
• This function prints the event it receives and returns a response with a 200 HTTP status code and a body containing the message 'Hello from Lambda!'

Expected Output:
A response with a 200 HTTP status code and a body containing the message 'Hello from Lambda!'

4. Summary

In this tutorial, we have gone over the architecture of AWS Lambda, its components, and a sample Lambda function. For further learning, you should explore different types of event sources and how to handle them in your Lambda functions.

5. Practice Exercises

Exercise 1: Create a Lambda function that reads data from an S3 bucket and logs the data.

Exercise 2: Create a Lambda function that is triggered by an HTTP request and returns the current date and time.

Tips for further practice:
- Explore different types of event sources and how to handle them in your Lambda functions.
- Learn about error handling and retry behavior in AWS Lambda.
- Learn how to monitor your Lambda functions using Amazon CloudWatch.