Use pt-online-schema-change or gh-ost or ocs_cli for MySQL Online schema changes?

[Slach]

would like someone implements support one of following tools?
for your great tool
https://www.percona.com/doc/percona-toolkit/LATEST/pt-online-schema-change.html
https://github.com/github/gh-ost
https://github.com/facebookincubator/OnlineSchemaChange

[JensRantil]

What problem are you trying to solve? MySQL 5.6(?) introduced Online DDL which allows online ALTERs.

[Slach]

as you can see
https://blog.pythian.com/depth-mysql-5-6-ddl/
pt-online-schema-change and other like tools can throttle disk usage and don't lock table in some cases change column type, add fulltext index etc.