nexus/sreweekly/markdown/138/03-colmmacc-on-twitter-shuffle-sharding.md

# @colmmacc on Twitter: shuffle sharding

- **期号**: SRE Weekly Issue #138（2018-09-09）
- **作者**: Colm MacCárthaigh — AWS (thanks to Thread Reader for the thread rollup)
- **链接**: https://threadreaderapp.com/thread/1034492056968736768.html?utm_source=last_week_in_AWS&utm_medium=newsletter&utm_campaign=website&utm_source=Last%20Week%20in%20AWS&utm_medium=email

## 简介

Colm MacCárthaigh explains how shuffle sharding improves reliability by acting like some kind of magic lever made of math.

## 正文

![Profile picture](https://threadreaderapp.com/images/avatars/14340150.jpg) 

[@colmmacc](https://twitter.com/colmmacc)




![Profile picture](https://threadreaderapp.com/images/Twitter_Logo_Blue.png)

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[gist.github.com/colmmacc/4a39a…](https://gist.github.com/colmmacc/4a39a6416d2a58b6c70bc73027bea4dc). Try it for Route 53's numbers. There are 2048 Route 53 virtual name servers, and each hosted zone is assigned to 4. So n = 2048, and m = 4.

[github.com/awslabs/route5…](https://github.com/awslabs/route53-infima)

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[en.wikipedia.org/wiki/Lottery_m…](https://en.wikipedia.org/wiki/Lottery_mathematics)has good background on how we then come to this equation ...

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