RestAPI vs WebSocket Guide
Tags: livestreaming, restvswebsocket, restapi, development
Published: 2024-01-18 12:40:19

This article explores the considerations and design approaches for using REST and WebSocket protocols in finance applications, cricket streaming, and stock market systems.

### Finance Application

#### Design Approach
For finance applications, a balance between simplicity and real-time responsiveness is crucial. The chosen approach involves utilizing REST for standard data retrieval and non-real-time functionalities, while WebSocket is integrated for real-time market updates and live trading information.

#### Pros and Cons
- **REST:**
  - Pros: Simple request-response model, scalability, and wide technology support.
  - Cons: Real-time updates may be challenging, increased latency for frequent updates.

- **WebSocket:**
  - Pros: Real-time bidirectional communication, low-latency updates, efficient for streaming financial data.
  - Cons: Overhead for non-real-time functionalities, implementation complexity.

### Cricket Streaming

#### Design Approach
In the context of cricket streaming, the approach involves employing REST for on-demand content and initial data retrieval, while WebSocket is integrated to ensure low-latency updates during matches.

#### Pros and Cons
- **REST:**
  - Pros: Easy integration with standard media formats, simplicity for on-demand content.
  - Cons: Limited suitability for live streaming due to latency.

- **WebSocket:**
  - Pros: Low-latency bidirectional communication, efficient for real-time streaming.
  - Cons: Potential complexities in managing connections.

### Stock Market

#### Design Approach
For stock market applications, a hybrid approach is adopted. REST is implemented for historical data retrieval and less time-sensitive operations, while WebSocket is integrated for real-time market data, especially for high-frequency trading scenarios.

#### Pros and Cons
- **REST:**
  - Pros: Simplicity in data retrieval, widely adopted and standardized.
  - Cons: May not meet real-time requirements for high-frequency trading.

- **WebSocket:**
  - Pros: Real-time updates for stock prices, efficient handling of large volumes of streaming data.
  - Cons: Requires careful consideration for scalability.

### Overall Considerations

#### Scalability
REST is generally easier to scale due to its statelessness. WebSocket scalability requires careful management of connections.

#### Latency
WebSocket excels in low-latency scenarios, making it suitable for real-time applications. REST may introduce latency for frequent updates.

#### Complexity
REST is simpler to implement, while WebSocket may introduce more complexity in managing connections and handling real-time updates.

#### Efficiency
WebSocket proves efficient for real-time bidirectional communication, especially in scenarios demanding low-latency updates.

#### Suitability
The choice between REST and WebSocket depends on the specific requirements of each application. REST is suitable for non-real-time functionalities and standard data retrieval, while WebSocket is ideal for real-time scenarios.

#### Consistency
REST ensures consistent data retrieval, while WebSocket's real-time updates may introduce variations in data freshness.

The selection of a communication protocol depends on the nature of the application, with a hybrid approach often providing the best of both worlds. Careful consideration of the pros and cons, along with a thorough understanding of specific use case requirements, is essential for making informed decisions in the dynamic landscape of real-time applications. By selectively applying each protocol, developers strike a balance between simplicity and real-time responsiveness, creating versatile applications that cater to various use cases efficiently.
Let's explore two industry examples: a financial trading platform and a live sports streaming service.

#### **Financial Trading Platform: Interactive Brokers**

Interactive Brokers, a prominent online brokerage firm, employs a hybrid communication model to provide a seamless and responsive trading experience. The platform leverages RESTful APIs for standard data retrieval, account management, and non-real-time functionalities. This includes actions like account balance inquiries, transaction history, and placing non-urgent orders.

On the other hand, Interactive Brokers utilizes WebSocket for real-time market data updates, order executions, and live trading information. The WebSocket protocol ensures low-latency communication, making it suitable for high-frequency trading scenarios where split-second decisions are critical.

#### **Live Sports Streaming Service: ESPN+**

ESPN+, a popular sports streaming service, employs a hybrid approach to deliver live sports content with minimal latency. REST APIs are used for on-demand content retrieval, account management, and initial data fetching. This includes features such as accessing archived games, managing user profiles, and retrieving schedule information.

However, for delivering live sports events, ESPN+ integrates WebSocket to ensure real-time updates during matches. This includes live scores, play-by-play commentary, and instant notifications. WebSocket's bidirectional communication proves essential in providing users with an immersive and up-to-the-moment viewing experience, especially during fast-paced sports events.

#### **Development Strategies:**

1. **Identify Use Cases:**
   - Determine functionalities that can be handled asynchronously and those that require real-time updates.
   - Use REST for standard data retrieval, historical data, and non-real-time operations.
   - Integrate WebSocket for live updates, real-time events, and critical user interactions.

2. **API Design:**
   - Design RESTful APIs for simplicity, standardization, and ease of integration.
   - Develop WebSocket endpoints for bidirectional communication, emphasizing low-latency updates.

3. **Scalability:**
   - Implement load balancing for REST APIs to handle a large number of concurrent requests.
   - Use connection pooling and clustering techniques for WebSocket to manage scalable real-time communication.

4. **Error Handling:**
   - Implement robust error handling mechanisms for both REST and WebSocket to ensure graceful degradation and user experience.

5. **Security Measures:**
   - Apply industry-standard security practices, including SSL/TLS for encryption, API key authentication for REST, and secure WebSocket connections.

6. **Testing:**
   - Conduct thorough testing for both REST and WebSocket functionalities, including stress testing, to ensure scalability and reliability.

7. **Monitoring and Analytics:**
   - Implement monitoring tools to track the performance of both communication protocols.
   - Utilize analytics to gather insights into user interactions, allowing continuous optimization.

By adopting this hybrid approach, products like Interactive Brokers and ESPN+ achieve a delicate balance, leveraging the strengths of both REST and WebSocket to deliver a comprehensive and responsive user experience. The key lies in strategically applying each protocol to the aspects of the application where it excels, ultimately providing users with a feature-rich and high-performance platform.