Creating and maintaining APIs in AWS primarily involves using Amazon API Gateway, a fully managed service that enables developers to create, publish, and manage APIs at any scale. API Gateway acts as the front door for applications to access backend services, Lambda functions, or other AWS services…Creating and maintaining APIs in AWS primarily involves using Amazon API Gateway, a fully managed service that enables developers to create, publish, and manage APIs at any scale. API Gateway acts as the front door for applications to access backend services, Lambda functions, or other AWS services.
To create an API, developers can choose between REST APIs, HTTP APIs, or WebSocket APIs depending on their use case. REST APIs offer comprehensive features including request validation, transformation, and caching. HTTP APIs provide a cost-effective, lower-latency option for simple proxy scenarios. WebSocket APIs enable real-time two-way communication.
The API creation process involves defining resources (URL paths), methods (GET, POST, PUT, DELETE), and integrations that connect to backend services. Integration types include Lambda functions, HTTP endpoints, AWS services, and mock responses for testing.
Stages represent different environments like development, staging, and production. Each stage can have unique configuration settings, variables, and deployment histories. Stage variables allow dynamic configuration changes across environments.
Maintaining APIs requires implementing proper security through IAM policies, Lambda authorizers, Cognito user pools, or API keys with usage plans. Usage plans control throttling limits and quota management for different client tiers.
Monitoring and logging are essential maintenance tasks. CloudWatch provides metrics for latency, error rates, and request counts. Access logging and execution logging help troubleshoot issues and audit API usage.
API versioning strategies help manage changes over time. Developers can use path-based versioning (/v1/resource), header-based versioning, or query parameter versioning to maintain backward compatibility.
Caching responses at the API Gateway level reduces backend load and improves response times. Cache settings can be configured per method with customizable TTL values.
Documentation and SDK generation features help API consumers understand and integrate with your APIs effectively, making adoption easier for development teams.
Creating and Maintaining APIs - AWS Developer Associate Guide
Why is Creating and Maintaining APIs Important?
APIs (Application Programming Interfaces) are the backbone of modern cloud applications. They enable communication between different services, applications, and systems. For AWS developers, understanding how to create and maintain APIs is essential because:
• APIs allow you to build scalable, decoupled architectures • They enable microservices communication • APIs provide secure access to your application's functionality • They are fundamental to serverless application development • Proper API management ensures reliability and performance
What is API Creation and Maintenance in AWS?
In AWS, API creation and maintenance primarily revolves around Amazon API Gateway, a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale.
Key Components: • REST APIs - Traditional RESTful APIs with full API management features • HTTP APIs - Lower-latency, cost-effective APIs for simple use cases • WebSocket APIs - For real-time, two-way communication applications
How Does It Work?
1. API Gateway Architecture: API Gateway acts as a front door for applications to access data, business logic, or functionality from backend services. It handles: • Request/response transformations • Authentication and authorization • Throttling and rate limiting • Caching responses • Request validation
2. Integration Types: • Lambda Integration - Connects to AWS Lambda functions • HTTP Integration - Connects to HTTP endpoints • AWS Service Integration - Connects to other AWS services • Mock Integration - Returns responses from API Gateway itself • VPC Link Integration - Connects to private resources in VPC
3. Stages and Deployment: • APIs are deployed to stages (dev, staging, prod) • Each stage has its own configuration and variables • Stage variables allow dynamic configuration • Canary deployments enable gradual rollouts
4. Security Features: • IAM Authorization - Uses AWS credentials for access control • Lambda Authorizers - Custom authorization logic using Lambda • Cognito User Pools - User authentication and authorization • API Keys and Usage Plans - Rate limiting and quota management • Resource Policies - Control access from specific sources
5. Monitoring and Maintenance: • CloudWatch Logs for request/response logging • CloudWatch Metrics for performance monitoring • X-Ray integration for distributed tracing • Access logging for audit purposes
Key Concepts for the Exam:
• Mapping Templates - Transform request/response payloads using VTL (Velocity Template Language) • Models - Define the structure of request/response data using JSON Schema • CORS - Enable cross-origin requests by configuring appropriate headers • Throttling - Default limits are 10,000 requests per second with 5,000 burst • Caching - Reduce backend calls with configurable TTL (0.5 to 300 seconds) • Custom Domain Names - Use your own domain with ACM certificates
Exam Tips: Answering Questions on Creating and Maintaining APIs
1. Know the Integration Types: When a question asks about connecting API Gateway to backend services, understand which integration type is appropriate. Lambda Proxy integration passes the entire request to Lambda, while Lambda Custom integration allows request transformation.
2. Security Questions: • For user authentication scenarios, think Cognito User Pools • For AWS service-to-service communication, think IAM authorization • For custom token validation, think Lambda Authorizers • For IP-based restrictions, think Resource Policies
3. Performance and Scaling: • API Gateway scales automatically • Enable caching to reduce latency and backend load • Use throttling to protect backend services from overload • HTTP APIs are faster and cheaper than REST APIs for simple use cases
4. Common Exam Scenarios: • 429 Too Many Requests - Indicates throttling; implement exponential backoff • 502 Bad Gateway - Backend integration issue; check Lambda timeout or response format • 504 Gateway Timeout - Integration timeout (29 seconds max for API Gateway)
5. Deployment Best Practices: • Use stage variables for environment-specific configuration • Implement canary deployments for safe rollouts • Enable CloudWatch logging for troubleshooting • Use OpenAPI/Swagger for API definition and import
6. Remember These Limits: • Maximum integration timeout: 29 seconds • Maximum payload size: 10 MB • Maximum WebSocket message size: 128 KB • Cache size: 0.5 GB to 237 GB
7. Cost Optimization Questions: • HTTP APIs are up to 70% cheaper than REST APIs • Enable caching to reduce the number of backend invocations • Use usage plans to control API consumption
Final Exam Strategy: Read questions carefully to identify whether they ask about REST APIs or HTTP APIs, as features differ between them. Pay attention to keywords like 'real-time' (WebSocket), 'cost-effective' (HTTP APIs), or 'full-featured' (REST APIs) to guide your answer selection.