lambda

# AWS Lambda AWS Lambda runs code without provisioning servers. You pay only for compute time consumed. Lambda automatically scales from a few requests per day to thousands per second. ## Table of Contents - [Core Concepts](#core-concepts) - [Common Patterns](#common-patterns) - [CLI Reference](#cli-reference) - [Best Practices](#best-practices) - [Troubleshooting](#troubleshooting) - [References](#references) ## Core Concepts ### Function Your code packaged with configuration. Includes runtime, handler, memory, timeout, and IAM role. ### Invocation Types | Type | Description | Use Case | |------|-------------|----------| | **Synchronous** | Caller waits for response | API Gateway, direct invoke | | **Asynchronous** | Fire and forget | S3, SNS, EventBridge | | **Poll-based** | Lambda polls source | SQS, Kinesis, DynamoDB Streams | ### Execution Environment Lambda creates execution environments to run your function. Components: - **Cold start**: New environment initialization - **Warm start**: Reusing existing environment - **Handler**: Entry point function - **Context**: Runtime information ### Layers Reusable packages of libraries, dependencies, or custom runtimes (up to 5 per function). ## Common Patterns ### Create a Python Function **AWS CLI:** ```bash # Create deployment package zip function.zip lambda_function.py # Create function aws lambda create-function \ --function-name MyFunction \ --runtime python3.12 \ --role arn:aws:iam::123456789012:role...