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Netflix System Design

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Netflix System Design

Aman kant Mahto's photo
Aman kant Mahto
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3 min read

Overview

Netflix, a leader in the world of online streaming, provides millions of users with seamless access to movies and TV shows. This document explains the architecture and design of Netflix in a simplified way.

Key Components of Netflix System Design

Netflix's system comprises several interconnected components:

1. Client (User Interface)

  • Devices like TVs, laptops, mobile phones, and gaming consoles.

  • Used to browse, search, and stream content.

2. Open Connect (Netflix CDN)

  • Netflix’s custom Content Delivery Network (CDN).

  • Ensures faster video streaming by serving content from servers located close to users.

  • Reduces latency by delivering content from the nearest Open Connect server.

3. Backend (Database and Processing)

  • Handles tasks like user accounts, video onboarding, recommendations, billing, and customer support.

  • Uses Amazon Web Services (AWS) for scalability and reliability.

Netflix’s Microservices Architecture

Netflix’s system is built using microservices, where each service handles a specific task. For instance:

  • Video storage and transcoding services work independently.

  • User data services manage profiles, history, and recommendations.

Benefits of Microservices:

  • Independent scalability.

  • Better fault isolation.

  • Easier updates and maintenance.

Strategies for Reliable Microservices:

  • Critical Services Isolation: Basic functionalities like search and playback are prioritized to ensure availability.

  • Stateless Servers: Services are designed to function without depending on specific servers. If one fails, another takes over seamlessly.

How Netflix Processes Videos

  1. Video Onboarding:

    • Netflix receives high-quality video files from production houses.

    • Files undergo transcoding to create different formats and resolutions for various devices and network speeds.

    • Approximately 1,200 replicas are created for each video.

  2. Distribution:

    • Replicas are distributed across Open Connect servers worldwide.

  3. Streaming:

    • When a user plays a video, Netflix selects the best server based on location, device, and network conditions.

Handling High Traffic Loads

Netflix employs several techniques to manage millions of simultaneous users:

1. Elastic Load Balancer (ELB):

  • Distributes user traffic across servers using a two-tier approach:

    1. Balances traffic across geographical zones.

    2. Distributes traffic within zones to specific servers.

2. ZUUL Gateway:

  • Routes, monitors, and secures traffic.

  • Enables traffic distribution and load testing on specific servers.

3. Hystrix:

  • Prevents cascading failures in the system.

  • Isolates services to manage latency and failures gracefully.

  • Ensures real-time monitoring and rapid recovery.

Data Management

Netflix’s data infrastructure is designed for scalability and performance:

1. Caching with EV Cache:

  • Frequently accessed data is stored in memory for faster retrieval.

  • Built on Memcached with custom enhancements for reliability and performance.

2. Data Processing:

  • Uses Apache Kafka and Chukwa for real-time data ingestion.

  • Processes logs, UI activities, and video viewing events.

  • Employs Apache Spark for personalized recommendations and data analytics.

3. Search with Elasticsearch:

  • Helps customer support and playback teams troubleshoot issues quickly.

  • Tracks system errors, resource usage, and login problems.

Personalized Recommendations

Netflix’s recommendation system relies on:

Algorithms:

  1. Collaborative Filtering:

    • Predicts user preferences based on similar user behaviors.

  2. Content-Based Filtering:

    • Suggests content similar to what a user has already watched.

Data Sources:

  • Viewing history, ratings, device usage, and activity times.

  • Metadata like movie genres, actors, and release years.

Database Design

Netflix uses a combination of relational and NoSQL databases:

1. MySQL (RDBMS):

  • Stores critical data like billing and user information.

  • Deployed on Amazon EC2 with high availability through master-master replication.

2. Cassandra (NoSQL):

  • Handles large-scale data like viewing histories.

  • Optimized for high write and read performance.

  • Data is compressed to reduce storage and improve performance.

Summary

Netflix’s system design is a masterpiece of scalability, reliability, and performance. It combines cutting-edge technologies and architectural practices to deliver a seamless user experience. From microservices to machine learning, every aspect of Netflix’s system is designed to handle the massive scale and complexity of modern streaming demands.