Have you ever deployed a feature which interrupted your application because the schema change on the MySQL database has locked the table? Then I have good news for you! There are some tools like the Percona Toolkit which can apply the operation without a downtime.

When we prepared the relaunch of diginights.com with our new and awesome responsive layout, we needed to resize a bunch of flyer, location and avatar images (~1.000.000). One of our requirements was that we save the images with a new tag so we won’t affect the running application.