Making Migrations Faster and Safer | Engine Yard Blog

Making Migrations Faster and Safer | Engine Yard Blog

Are your migrations the execute-and-pray variety? If so, you are probably not (yet!) running a large application. Even small applications can benefit from a more careful migration process. It’s important to establish the process now, before things get big, because it will be much more difficult later. In my study of emergency issues filed by Percona’s customers, the single most valuable preventive measure I identified was change control. Migrations involve change, and the more disciplined and careful you are, the less opportunity for problems, and the more safeguards you can build in to help recover quickly if a problem ever does occur. The single best way to prevent bad changes from happening in production is to execute them in a non-production environment and observe the system. As you might know, ALTER TABLE is generally a blocking operation in MySQL. It can be very har...

Full article: http://www.engineyard.com/blog/2011/making-migrations-fas...