System Design SNAKE原则 (以NetFlix为例) | Now Now Now

System Design SNAKE原则 (以NetFlix为例) | Now Now Now

Scenario

Necessary: constrain/hypothesis

1. Daily active user? Ask! eg. 5,000,000
2. Predict
   1. User
      1. Average Concurrent Users = daily_active_user * average_online_time / daily_seconds
         = 5,000,000 * (30*60) / (24*60*60)
         = 104,167/s
      2. Peak users = average_concurrent_users * 6 = 625,000/s
   2. Traffic
      1. Video traffic speed = 3mbps
      2. MAX
   3. Memory
      1. Memory per user = 10KB
      2. MAX daily memory = 5,000,000 * 2 * 10 = 100GB
         (T级以内的内存都是可以解的)
   4. Storage
      1. Total movie = 14,000
      2. Movie storage (视频会有不同版本) = total_movie * average_movie_size = 14,000*50GB = 700TB

Application: service/algorithm 模块设计

Kilobit: data 数据设计， 不同数据的存储模型

1. 比如用户服务可以用mysql, 查询逻辑强
2. 电影文件就用文件存，不用数据库

Evolve: 和面试官沟通

1. Step1: Analyze
   1. with
      1. More constrains
      2. New use cases
      3. Deeper, more details
   2. from the views of
      1. Performance
      2. Scalability
      3. Robustness
2. According to 面试官, 加深某一部分的设计

Read full article from System Design SNAKE原则 (以NetFlix为例) | Now Now Now