# Tag: deploy

• ### Zero Downtime Migrations

August 15, 2015

For any sufficiently large application, you want to minimize interruptions to service while deploying new code. This is especially challenging for migrations on Heroku and other Platforms-as-a-Service, where you have a Catch-22 problem; you want to run your migrations, first, but you can’t run them until you’ve deployed the migrations to production. Usually, at this point, your new migration-dependent features are in the deploy, too. So when your application restarts, and the migration hasn’t run, yet, your poor application will trip some exceptions, and perhaps, create problems for your users. Of course, you could put the app into maintenance mode, but that creates more downtime for your users.

• ### Deploy Strategies for HerokuSan

May 12, 2012

If you look at the network graphs of heroku_san on github, you'll see a number of branches where the only change is the deletion of the following line from the deploy task:

• ### Dry DevOps with HerokuSan

March 25, 2012
1. How many times (each day) have you typed this at your console?
git push heroku master and then forgotten to run
heroku run rake db:migrate --app yellow-snow-3141 or
heroku ps:restart
2. Does your script support a multi-stage environments?
3. Do you remember how to get to the application's console process?
4. Is your application's configuration consistent across all stages?
5. Are you deploy scripts tested?
deploy - Ken Mayer