Tips for performing a successful software migration
Migrations are part of real-world software engineering. If you don’t migrate, your code will probably rot. You probably need to make changes to your software systems in order to adapt it to the changing environment.
Recently, we had a small migration in our team. We wanted to replace our configuration mechanism from one to another. Unfortunately, it didn’t go smoothly. As I was performing the migration, I caused two similar outages. After talking to a few colleagues, I was suggested to take a step back and to think about migrations at a higher level. What makes a good migration? How to perform migrations safely? I’ve gone back to past migrations I was part of, or just seen from the sidelines, and thought about what it was that made them good, safe or maybe even awesome. I also thought about what made some migration a nightmare.
Migrate from one build system to another. Update your service’s API from version N to version (N+1). Migrate your configuration mechanism from one to another. Migrate your underlying machine type from one to another. Migrate from using one datastore to another. Update your service’s runtime from one version to another.
