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Flaws in the Cache, Counters and Ip+user based

Courses
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#1

Hi @Design_Gurus

There are some flaws:

  1. Why do we need cache when we have everything in Redis already? Also, even if we cache loss, we may not be at loss. By the time the new server will get up, the old limits wont make any sense.

  2. Sliding window with counters: If we normalise to minute, and if there are three time stamps, in same window,how would you know which one to expire when? we need to store all entries, else you cant expire. Lets say 4:10:05. 4:10:06, both goes to 4-5 windows and count is 2, but these have different expiry.

  3. At last, throttling based on ip+user : if hacker have infinite ip v6, then hacker can generate infinite ipv6 here also. it wont help

Course: Grokking the System Design Interview - Learn Interactively
Lesson: Designing a URL Shortening service like TinyURL - Grokking the System Design Interview

Course: Grokking the System Design Interview - Learn Interactively
Lesson: Designing a URL Shortening service like TinyURL - Grokking the System Design Interview

Course: Grokking the System Design Interview - Learn Interactively
Lesson: Designing a URL Shortening service like TinyURL - Grokking the System Design Interview

#2

why Course and Lesson is coming three times in question and why it is not picking rate limiter tag, despite me giving that. @Design_Gurus