System Design 101: 10 Essential Components of a Production Web Application

生产环境 Web 应用程序的 10 个基本组成部分

1. CI/CD Pipelines

1. CI/CD 管道

What: CI/CD pipelines automate the process of deploying code to server instances.
什么: CI/CD 管道自动化代码部署到服务器实例的过程。

Why: They ensure code changes are tested and deployed seamlessly, improving deployment efficiency and reliability.
为什么: 它们确保代码更改得到测试并无缝部署,提高部署效率和可靠性。

Who: Typically handled by DevOps engineers or software developers.
谁: 通常由 DevOps 工程师或软件开发人员处理。

Where: Tools like Jenkins and GitHub Actions are commonly used.
在哪里: 通常使用像 Jenkins 和 GitHub Actions 这样的工具。

When: Triggered on code commits, pull requests, or scheduled intervals.
什么时候: 在代码提交、拉取请求或预定时间间隔时触发。

Examples:
例子:

  • Use Jenkins to automate the deployment process, ensuring that code changes are tested and deployed seamlessly.
    使用 Jenkins 自动化部署过程,确保代码更改得到测试并无缝部署。
  • GitHub Actions can be configured to trigger builds and deployments whenever code is pushed to the main branch.
    可以配置 GitHub Actions,在代码推送到主分支时触发构建和部署。

2. User Requests

2. 用户请求

What: User requests originate from the web browser and reach app servers after DNS resolution.
什么: 用户请求来自于 Web 浏览器,经过 DNS 解析后到达应用服务器。

Why: To access the web application and retrieve content or data.
为什么: 访问 Web 应用程序并检索内容或数据。

Who: End-users interacting with the web application.
谁: 与 Web 应用程序交互的最终用户。

Where: Originates from user browsers and routed through DNS servers to app servers.
在哪里: 来源于用户浏览器,通过 DNS 服务器路由到应用服务器。

When: Whenever users navigate to the web application’s URL.
什么时候: 每当用户导航到 Web 应用程序的 URL 时。

Examples:
例子:

  • A user types a URL into their browser, and the DNS translates this URL into the IP address of the app server.
    用户在浏览器中输入 URL,DNS 将该 URL 转换为应用服务器的 IP 地址。
  • Using a DNS provider like Cloudflare to manage DNS resolution and improve request routing efficiency.
    使用像 Cloudflare 这样的 DNS 提供商来管理 DNS 解析并提高请求路由效率。

3. Load Balancers and Reverse Proxies

3. 负载均衡器和反向代理

What: Distribute user requests evenly across web application servers.
什么: 将用户请求均匀分布到 Web 应用服务器。

Why: To ensure high availability and optimize resource utilization.
为什么: 确保高可用性并优化资源利用。

Who: Managed by DevOps engineers or system administrators.
谁: 由 DevOps 工程师或系统管理员管理。

Where: Located between user requests and app servers.
在哪里: 位于用户请求和应用服务器之间。

When: Continuously, as long as the web application is operational.
什么时候: 持续进行,只要 Web 应用程序在运行。

Examples:
例子:

  • Nginx can be set up as a reverse proxy to handle incoming traffic and distribute it to multiple app servers.
    可以将 Nginx 设置为反向代理来处理传入流量并将其分发到多个应用服务器。
  • HAProxy can be used to ensure high availability and load balancing across servers.
    可以使用 HAProxy 来确保服务器的高可用性和负载均衡。

4. Content Delivery Network (CDN)

4. 内容分发网络(CDN)

What: Serve requests by caching content closer to users.
什么: 通过将内容缓存到用户附近来提供请求服务。

Why: To reduce latency and improve load times for users.
为什么: 减少延迟并提高用户的加载时间。

Who: Managed by DevOps engineers or network administrators.
谁: 由 DevOps 工程师或网络管理员管理。

Where: Globally distributed servers.
在哪里: 全球分布的服务器。

When: Used continuously to serve static and dynamic content.
什么时候: 持续使用,以提供静态和动态内容。

Examples:
例子:

  • Implementing Cloudflare or Akamai to cache static assets close to the user’s location to reduce latency.
    实施 Cloudflare 或 Akamai,将静态资产缓存到靠近用户的位置以减少延迟。
  • Using AWS CloudFront to distribute content globally, enhancing the user experience by reducing load times.
    使用 AWS CloudFront 在全球分发内容,通过减少加载时间来增强用户体验。

5. Backend Services and APIs

5. 后端服务和 API

What: Enable communication between frontend and backend services.
什么: 使前端和后端服务之间的通信成为可能。

Why: To fetch, manipulate, and serve data.
为什么: 获取、操作和提供数据。

Who: Developed and maintained by software developers.
谁: 由软件开发人员开发和维护。

Where: Backend servers and microservices.
在哪里: 后端服务器和微服务。

When: Whenever data is requested or manipulated.
什么时候: 每当请求或操作数据时。

Examples:
例子:

  • A REST API developed with Express.js allows the frontend to fetch and manipulate data stored in the backend.
    使用 Express.js 开发的 REST API 允许前端获取和操作存储在后端的数据。
  • GraphQL can be used to enable clients to request exactly the data they need, improving efficiency and performance.
    可以使用 GraphQL,使客户端能够准确地请求所需数据,提高效率和性能。

6. Database Servers and Distributed Caches

6. 数据库服务器和分布式缓存

What: Store and retrieve data for backend services.
什么: 存储和检索后端服务的数据。

Why: To ensure efficient data management and retrieval.
为什么: 确保高效的数据管理和检索。

Who: Managed by database administrators and backend developers.
谁: 由数据库管理员和后端开发人员管理。

Where: Database servers and cache servers.
在哪里: 数据库服务器和缓存服务器。

When: Continuously, as data is read from and written to the database.
什么时候: 持续进行,当数据从数据库读取和写入时。

Examples:
例子:

  • Using PostgreSQL for relational database management and Redis for caching frequently accessed data.
    使用 PostgreSQL 进行关系数据库管理,使用 Redis 缓存频繁访问的数据。
  • MongoDB as a NoSQL database for handling large volumes of unstructured data.
    使用 MongoDB 作为 NoSQL 数据库来处理大量非结构化数据。

7. Job Workers and Queues

7. 工作任务和队列

What: Handle resource-intensive and long-running tasks asynchronously.
什么: 异步处理资源密集型和长时间运行的任务。

Why: To offload heavy processing tasks from the main application.
为什么: 将繁重的处理任务从主应用程序卸载。

Who: Implemented by backend developers.
谁: 由后端开发人员实施。

Where: Separate job worker servers.
在哪里: 单独的工作节点服务器。

When: Triggered when tasks require background processing.
什么时候: 在任务需要后台处理时触发。

Examples:
例子:

  • RabbitMQ can be used to manage the job queue, ensuring tasks are processed asynchronously by worker nodes.
    可以使用 RabbitMQ 来管理作业队列,确保任务由工作节点异步处理。
  • Using Celery with a Redis broker to handle background job processing in a Python web application.
    使用 Celery 和 Redis 代理在 Python Web 应用中处理后台作业。

8. Full-Text Search Service

8. 全文搜索服务

What: Provide search functionality for the web application.
什么: 为 Web 应用程序提供搜索功能。

Why: To enable users to search through large volumes of data efficiently.
为什么: 使用户能够高效地搜索大量数据。

Who: Implemented by backend developers.
谁: 由后端开发人员实施。

Where: Search servers or integrated within the backend.
在哪里: 搜索服务器或集成在后端中。

When: Used whenever search queries are made by users.
什么时候: 每当用户进行搜索查询时使用。

Examples:
例子:

  • Elasticsearch enables real-time search and analytics for large volumes of data, providing quick search results to users.
    **Elasticsearch 使大数据量的实时搜索和

分析成为可能,为用户提供快速的搜索结果。**

  • Apache Solr can be integrated to handle complex search queries and improve search performance.
    可以集成 Apache Solr 以处理复杂的搜索查询并提高搜索性能。

9. Monitoring Tools

9. 监控工具

What: Store logs and analyze data to ensure the application runs smoothly.
什么: 存储日志并分析数据以确保应用程序顺利运行。

Why: To detect and resolve issues promptly, maintaining application health.
为什么: 及时检测和解决问题,维护应用程序健康。

Who: Used by DevOps engineers and system administrators.
谁: 由 DevOps 工程师和系统管理员使用。

Where: Integrated within the application infrastructure.
在哪里: 集成在应用程序基础设施中。

When: Continuously monitoring application performance and errors.
什么时候: 持续监控应用程序性能和错误。

Examples:
例子:

  • Sentry can be used to monitor application errors and exceptions, providing detailed reports for debugging.
    可以使用 Sentry 来监控应用程序错误和异常,提供详细的调试报告。
  • Grafana, in combination with Prometheus, can visualize metrics and logs, helping to maintain the health of the application.
    Grafana 与 Prometheus 结合,可以可视化指标和日志,帮助维护应用程序的健康状态。

10. Alerting Services

10. 警报服务

What: Notify developers of issues through various platforms.
什么: 通过各种平台通知开发人员问题。

Why: To ensure quick resolution of critical issues, minimizing downtime.
为什么: 确保快速解决关键问题,最大限度地减少停机时间。

Who: Utilized by DevOps teams and developers.
谁: 由 DevOps 团队和开发人员使用。

Where: Integrated with monitoring tools and communication platforms.
在哪里: 与监控工具和通信平台集成。

When: Triggered on detecting anomalies or critical errors.
什么时候: 在检测到异常或关键错误时触发。

Examples:
例子:

  • Integrating PagerDuty with Slack to alert developers immediately when critical issues occur.
    将 PagerDuty 与 Slack 集成,在发生关键问题时立即提醒开发人员。
  • Using Opsgenie to send notifications to the development team based on predefined alert policies.
    使用 Opsgenie 根据预定义的警报策略向开发团队发送通知。

Comparison Table

Component Description Example Tools Role
CI/CD Pipelines Automate deployment processes Jenkins, GitHub Actions DevOps Engineers
User Requests Originates from browsers, reaches app servers via DNS Cloudflare End-users
Load Balancers and Reverse Proxies Distribute user requests across servers Nginx, HAProxy DevOps Engineers
Content Delivery Network (CDN) Cache content closer to users to reduce latency Cloudflare, AWS CloudFront DevOps Engineers
Backend Services and APIs Enable communication between frontend and backend Express.js, GraphQL Backend Developers
Database Servers and Caches Store and retrieve data efficiently PostgreSQL, Redis, MongoDB DB Admins, Backend Devs
Job Workers and Queues Handle long-running tasks asynchronously RabbitMQ, Celery Backend Developers
Full-Text Search Service Provide search functionality Elasticsearch, Apache Solr Backend Developers
Monitoring Tools Store logs and analyze data Sentry, Grafana, Prometheus DevOps Engineers
Alerting Services Notify developers of issues PagerDuty, Opsgenie DevOps Teams
graph TD;
    A[User Requests] -->|Browser| B(DNS)
    B --> C[Load Balancer]
    C --> D[App Server 1]
    C --> E[App Server 2]
    D --> F[Backend Services]
    E --> F
    F --> G[Database]
    F --> H[Cache]
    F --> I[Search Service]
    F --> J[Job Queue]
    J --> K[Job Workers]
    C --> L[CDN]

This diagram helps visualize the flow of user requests through various components of a production web application.
这张图帮助可视化用户请求通过生产环境 Web 应用程序的各种组件的流动。

Tips and Better Solutions

提示和更好的解决方案

  1. Use Blue-Green Deployment: This deployment strategy reduces downtime and risk by running two identical production environments.
    使用蓝绿部署: 这种部署策略通过运行两个相同的生产环境来减少停机时间和风险。
  2. Implement Rate Limiting: To prevent abuse and ensure fair usage of resources.
    实施速率限制: 防止滥用并确保资源的公平使用。
  3. Use Infrastructure as Code (IaC): Tools like Terraform help manage infrastructure through code, ensuring consistency and automation.
    使用基础设施即代码 (IaC): 像 Terraform 这样的工具通过代码管理基础设施,确保一致性和自动化。

Node.js Example for CI/CD

Node.js CI/CD 示例

Jenkinsfile:

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                sh 'npm install'
            }
        }
        stage('Test') {
            steps {
                sh 'npm test'
            }
        }
        stage('Deploy') {
            steps {
                sh 'npm run deploy'
            }
        }
    }
}

Explanation:
解释:

  • pipeline defines the Jenkins pipeline.
    pipeline 定义 Jenkins 管道。
  • agent any specifies that the pipeline can run on any available agent.
    agent any 指定管道可以在任何可用代理上运行。
  • stages are the different phases of the pipeline: Build, Test, Deploy.
    stages 是管道的不同阶段:构建、测试、部署。
  • steps inside each stage define the shell commands to run.
    每个阶段内的 steps 定义要运行的 shell 命令。

Python Example for CI/CD

Python CI/CD 示例

GitHub Actions Workflow:

name: CI/CD Pipeline

on:
  push:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Set up Python
        uses: actions/setup-python@v2
        with:
          python-version: '3.x'
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install -r requirements.txt
      - name: Test
        run: |
          pytest
      - name: Deploy
        run: |
          echo "Deploying to production"

Explanation:
解释:

  • name defines the name of the GitHub Actions workflow.
    name 定义 GitHub Actions 工作流程的名称。
  • on specifies the trigger events, here it’s set to push on the main branch.
    on 指定触发事件,这里设置为 main 分支上的 push
  • jobs define the different jobs in the workflow: build.
    jobs 定义工作流程中的不同作业:build
  • steps within the job define the actions to perform, such as checking out the code, setting up Python, installing dependencies, running tests, and deploying.
    作业中的 steps 定义要执行的操作,例如检出代码、设置 Python、安装依赖项、运行测试和部署。

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *