The development of software sometimes implies changes that affect the data model but such modifications have a series of problems such as the inability to stop the system or the volume of data to be reorganized.

In this post I want to talk about the existing tools for database schema change in MySQL, what limitations do those tools have if you use Galera for replication and how I have adapted gh-ost, the GitHub schema change tool, to be able to use it with Galera.