Category: Design Patterns

Design Patterns

Azure Messaging Patterns

Manjunath

This blog explores key messaging design patterns used in distributed systems architecture. These patterns help improve scalability, reliability, and performance in cloud-native applications.

Pattern Description Well-Architected Pillars
Asynchronous Request-Reply Decouples back-end processing from front-end, allowing async operations with a clear response. Performance Efficiency
Claim Check Splits large messages into a lightweight reference and a payload stored externally. Reliability, Security, Cost Optimization, Performance Efficiency
Competing Consumers Multiple consumers process messages from the same queue concurrently to improve throughput. Reliability, Cost Optimization, Performance Efficiency
Messaging Bridge Enables communication between incompatible messaging systems via an intermediary. Cost Optimization, Operational Excellence
Priority Queue Ensures high-priority messages are processed faster than others. Reliability, Performance Efficiency
Publisher/Subscriber Broadcasts events to multiple consumers asynchronously without tight coupling. Reliability, Security, Cost Optimization, Operational Excellence, Performance Efficiency
Queue-Based Load Leveling Buffers requests using a queue to handle load spikes smoothly. Reliability, Cost Optimization, Performance Efficiency
Sequential Convoy Processes related messages in order without blocking unrelated message groups. Reliability

These patterns are foundational for building robust cloud applications. For more, explore the full Azure Architecture Center.

Azure, Azure Integration Services, Design Patterns, Technology and tricks

Restful API design principles – Nutshell

Manjunath

HTTP VerbQueryDescription
GET /usersRetrieves a list of users
GET /users/8Retrieves a specific user
POST/usersCreates a new user
PUT/users/8Updates user #8
PATCH/users/8Partially updates
PATCH/users/8/statusUpdates status against user #8
DELETE/users/8Deletes user #8

RESTful APIs are vital for modern web applications, providing a flexible and scalable way for systems to communicate. Here’s a quick guide to key principles, best practices, HTTP methods, status codes, and common errors.

Key RESTful Principles

1. Uniform Interface: Resources identified by URLs (e.g., “/users/123”) using HTTP methods (“GET”, “POST”, etc.).
2. Stateless: Each request includes all information required; no session state stored server-side.
3. Client-Server Separation: Clients handle UI, while servers manage data and logic independently.
4. Cacheable: Define caching rules (e.g., “Cache-Control”) to improve performance.
5. Layered System: Clients interact with layers (e.g., proxies) without knowing internal server details.

Best Practices

1. Use Nouns in URLs: “/users”, not “/getUsers”.
2. Version Your API: “/v1/users”, to maintain backward compatibility.
3. Use Proper Status Codes: Ensure clear communication of the outcome.
4. Paginate Large Responses: For example, “GET /users?page=1&limit=50”.
5. Secure Your API: Use authentication (OAuth, API keys) and HTTPS.

HTTP Methods and REST Mapping

– GET: Retrieve data (read).
  – Example: “GET /users/123” – Get user with ID 123.
– POST: Create a new resource.
  – Example: “POST /users” – Create a new user.
– PUT: Update or replace an existing resource.
  – Example: “PUT /users/123” – Update user with ID 123.
– PATCH: Partially update a resource.
  – Example: “PATCH /users/123” – Update a user’s email.
– DELETE: Remove a resource.
  – Example: “DELETE /users/123” – Delete user with ID 123.

HTTP Status Codes

– Success:
  – “200 OK”: Request succeeded (GET, PUT).
  – “201 Created”: New resource created (POST).
  – “204 No Content”: Request successful, no content to return (DELETE).

– Client-Side Errors:
  – “400 Bad Request”: Malformed request.
  – “401 Unauthorized”: Authentication required.
  – “403 Forbidden”: Access denied.
  – “404 Not Found”: Resource not found.

– Server-Side Errors:
  – “500 Internal Server Error”: Generic server failure.
  – “502 Bad Gateway”: Invalid response from an upstream server.
  – “503 Service Unavailable”: Server temporarily unable to handle the request.

By following these principles and best practices, you can design scalable, secure, and maintainable RESTful APIs that provide a seamless experience for users and developers alike.