Design a Real-time Cryptocurrency Price Tracker System Design: Architecture & Trade-offs | DevExCode

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Design a Real-time Cryptocurrency Price Tracker

Introduction In this document, we will explore the design of a system for "Design a Real-time Cryptocurrency Price Tracker". The goal is to understand the requirements, challenges, and architectural decisions involved in building such a system.

Requirements

Functional Requirements

The core functionalities the system must provide include:

Tracking real-time cryptocurrency prices from multiple exchanges
Providing historical price data for analysis
Allowing users to set custom alerts for price changes

Specific use cases or scenarios include:

A trader who wants to stay up-to-date with the latest market trends and receive notifications when a cryptocurrency's price reaches a certain threshold.
An investor who needs to analyze historical price data to make informed investment decisions.

Non-Functional Requirements

The system must also meet non-functional requirements such as:

Performance: the system should be able to handle high traffic and respond quickly to requests (less than 500ms).
Scalability: the system should be able to scale horizontally to handle increased load.
Reliability: the system should have a high uptime percentage (greater than 99.9%).
Security: the system must protect user data and prevent unauthorized access.

High-Level Architecture The system will consist of the following components:

Data Collector: responsible for collecting real-time cryptocurrency price data from multiple exchanges.
Database: stores historical and current price data.
API Gateway: handles API requests and routes them to the appropriate service.
Alert Service: sends custom alerts to users when a cryptocurrency's price reaches a certain threshold.

The components will interact as follows:

code

          +---------------+
          |  Data Collector  |
          +---------------+
                  |
                  | (Websocket)
                  v
+---------------+       +---------------+
|        API Gateway      |       Alert Service     |
+---------------+       +---------------+
                  |
                  | (API Request)
                  v
+---------------+       +---------------+
|         Database     |       User Interface  |
+---------------+       +---------------+

Database Schema The database schema will consist of the following tables:

cryptocurrencies: stores information about each cryptocurrency, including its name and symbol.
price_data: stores historical and current price data for each cryptocurrency.
alerts: stores custom alerts set by users.

The relationships between the tables are as follows:

A cryptocurrency can have multiple price data entries (one-to-many).
An alert is associated with a specific cryptocurrency and user (many-to-one).

API Design

Key Endpoints

The system will provide the following API endpoints:

GET /cryptocurrencies: returns a list of all supported cryptocurrencies.
GET /cryptocurrencies/{id}/price: returns the current price of a specified cryptocurrency.
POST /alerts: creates a custom alert for a user.

Example requests and responses are as follows:

code

GET /cryptocurrencies

code

[{"name": "Bitcoin", "symbol": "BTC"}, {"name": "Ethereum", "symbol": "ETH"}]

code

GET /cryptocurrencies/1/price

code

{ "price": 50000, "timestamp": 1643723400 }

OpenAPI Specification

The system will follow the OpenAPI specification for API design.

System Flow The flow of data and control through the system is as follows:

The Data Collector collects real-time cryptocurrency price data from multiple exchanges.
The API Gateway receives API requests and routes them to the appropriate service.
The Alert Service sends custom alerts to users when a cryptocurrency's price reaches a certain threshold.
The Database stores historical and current price data.

Challenges and Solutions Potential challenges in designing and implementing the system include:

Data Quality: ensuring that the collected data is accurate and reliable.
Scalability: handling increased load and maintaining performance.
Security: protecting user data and preventing unauthorized access.

Solutions or trade-offs for each challenge are as follows:

Use data validation techniques to ensure data quality.
Implement horizontal scaling and caching to improve scalability.
Use encryption and secure authentication mechanisms to protect user data.

Scalability and Performance Strategies to ensure the system can handle increased load and maintain performance include:

Horizontal Scaling: adding more instances of the Data Collector and API Gateway services.
Caching: using a caching layer to reduce the number of database queries.
Load Balancing: distributing incoming traffic across multiple servers.

Security Considerations Security measures to protect the system and its data include:

Encryption: encrypting sensitive data and communications.
Secure Authentication: implementing secure authentication mechanisms for users.
Access Control: controlling access to sensitive data and services.

ASCII Diagrams

code

          +---------------+
          |  Data Collector  |
          +---------------+
                  |
                  | (Websocket)
                  v
+---------------+       +---------------+
|        API Gateway      |       Alert Service     |
+---------------+       +---------------+
                  |
                  | (API Request)
                  v
+---------------+       +---------------+
|         Database     |       User Interface  |
+---------------+       +---------------+

Sample SQL Schema SQL scripts for creating the database schema are as follows:

sql

CREATE TABLE cryptocurrencies (
    id INT PRIMARY KEY,
    name VARCHAR(255),
    symbol VARCHAR(10)
);

CREATE TABLE price_data (
    id INT PRIMARY KEY,
    cryptocurrency_id INT,
    price DECIMAL(16,8),
    timestamp TIMESTAMP,
    FOREIGN KEY (cryptocurrency_id) REFERENCES cryptocurrencies(id)
);

Example JSON API Response Example JSON responses for key API endpoints are as follows:

code

GET /cryptocurrencies

code

[{"name": "Bitcoin", "symbol": "BTC"}, {"name": "Ethereum", "symbol": "ETH"}]

code

GET /cryptocurrencies/1/price

code

{ "price": 50000, "timestamp": 1643723400 }

Conclusion In this blog post, we have explored the design and architecture of a system for collecting and storing real-time cryptocurrency price data. The system will provide an API for retrieving current prices and sending custom alerts to users. We have also discussed potential challenges and solutions for ensuring scalability, performance, and security.