Speaker Deck

GitHub's online schema migrations for MySQL

by Shlomi Noach

Published October 5, 2016 in Technology

gh-ost is a new tool by GitHub which changes the paradigm of MySQL online schema changes, designed to overcome today's limitations and difficulties in online migrations. gh-ost is:

- Triggerless: no triggers placed;
- Pausable: can suspend master writes altogether
- Lightweight: makes a low impact on the master database
- Controllable: one can interact with an executing gh-ost process, get info and reconfigure parameters
- Testable: gh-ost allows for testable, safe, non obtrusive migrations in production
- Designed to allow for multiple concurrent migrations

In this session we will:

- Introduce gh-ost, explain the reasoning for developing a new tool
- Describe the underlying logic
- Compare with existing online schema change tools
- Show off extra perks that make gh-ost operations so friendly
- Discuss the roadmap and present with surprising implications

gh-ost is open sourced under the MIT license