Show Notes
Cloudflare built a global cache purge system that runs under 150 ms.
This is how they did it.
Using RockDB to maintain local CDN cache, and a peer-to-peer data center distributed system and clever engineering, they went from 1.5 second purge, down to 150 ms.
However, this isn’t full picture, because that 150 ms is just actually the P50. In this video I explore Clouldflare CDN work, how the old core-based centralized quicksilver, lazy purge work compared to the new coreless, decentralized active purge. In it I explore the pros and cons of both systems and give you my thoughts of this system.
0:00 Intro
4:25 From Core Base Lazy Purge to Coreless Active
12:50 CDN Basics
16:00 TTL Freshness
17:50 Purge
20:00 Core-Based Purge
24:00 Flexible Purges
26:36 Lazy Purge
30:00 Old Purge System Limitations
36:00 Coreless / Active Purge
39:00 LSM vs BTree
45:30 LSM Performance issues
48:00 How Active Purge Works
50:30 My thoughts about the new system
58:30 Summary
Cloudflare blog
https://blog.cloudflare.com/instant-purge/
Mentioned Videos
Cloudflare blog
https://blog.cloudflare.com/instant-purge/
Percentile Tail Latency Explained (95%, 99%) Monitor Backend performance with this metric
https://www.youtube.com/watch?v=3JdQOExKtUY
How Discord Stores Trillions of Messages | Deep Dive
https://www.youtube.com/watch?v=xynXjChKkJc
Fundamentals of Operating Systems Course
Backend Troubleshooting Course
More from The Backend Engineering Show with Hussein Nasser
I discuss the state of what will be happening in the coming few years and why I encourage the 3 of you who want to be elite engineers to keep their critical thinking sharp. To pause and think before prompting.
This is a conversation with Rashed Hasan, a PhD Candidate from the University of Nebraska. We chatted about databases, ORMs and how to use AI without losing yourself. Rashed pagehttps://www.mdrashedulhasan.me/homepage
I discuss loops engineering and how it will numb creative thinking and critical system design for engineers.
I like SQL but the standard should have included ways to hint instead of the abstraction of "let me do it for you"
In this episode I explore why you should take some time to examine the operation you are caching before doing so. And why caching is a cop-out