# MySql Master Master Setup w/ Rails Migration Schema

**URL:** <https://www.ruby-forum.com/t/mysql-master-master-setup-w-rails-migration-schema/117983>\
**Category:** Rails\
**Created:** [October 22, 2007, 11:24pm UTC](https://www.ruby-forum.com/t/mysql-master-master-setup-w-rails-migration-schema/117983 "2007-10-22T23:24:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![kyle\_n](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/7cd45c/32.png) [@kyle\_n](https://www.ruby-forum.com/u/kyle_n)\
**Post date:** [October 22, 2007, 11:24pm UTC](https://www.ruby-forum.com/t/mysql-master-master-setup-w-rails-migration-schema/117983/1 "2007-10-22T23:24:05Z")

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Problem: When you alter tables in the free version of MySql (not  
Enterprise) running on a master / slave or master / master  
replication, the replication will stop in it’s tracks on any “ALTER  
TABLE” commands to one of the servers. Because rails uses this in  
migration.

Does anyone have a way of going about preventing this from happening,  
while the database is still live? My only suggestion is stopping the  
database replication. Running migration on both servers, then starting  
it again. But this is really risky I find.

Any other solutions?