# How we Upgraded a 22TB MySQL Cluster from 5.6 to 5.7 (in 9 months)

- **期号**: SRE Weekly Issue #71（2017-05-07）
- **作者**: —
- **链接**: https://thoughts.t37.net/how-we-upgraded-a-22tb-mysql-cluster-from-5-6-to-5-7-in-9-months-b09211af57ba

## 简介

The interesting bit in this story is that upgrading to 5.7 requires a full table rewrite (<tt>ALTER TABLE</tt>) for any table that has time-related columns. Their initial test-run took months and still hadn’t finished.

## 正文

> ⚠️ 抓取失败：URLError: [SSL: UNEXPECTED_EOF_WHILE_READING] EOF occurred in violation of protocol (_ssl.c:1032)