Migration Lock Timeout

Migration Lock Timeout is a Ruby gem that adds a lock timeout to all Active Record migrations in your Ruby on Rails project. A lock timeout sets a timeout on how long PostgreSQL will wait to acquire a lock on tables being altered before failing and rolling back. This prevents migrations from creating additional lock contention that can take down your site when it's under heavy load. Migration Lock Timeout currently only supports PostgreSQL

Installation

Add this line to your application's Gemfile:

gem 'migration-lock-timeout'

Usage

Configure the default lock timeout in a Rails initializer

#config/initializers/migration_lock_timeout.rb

MigrationLockTimeout.configure do |config|
  config.default_timeout = 5 #timeout in seconds
end

And that's all! Now every up migration will execute

SET LOCAL lock_timeout = '5s';

inside the migration transaction before your migration code runs. No lock timeout will be used for the down migration.

Disabling

You can disable the lock timeout by using:

  class AddFoo < ActiveRecord::Migration

    disable_lock_timeout!

    def change
      create_table :foo do |t|
        t.timestamps
      end
    end
  end

Custom lock timeout

You can change the duration of the lock timeout by using:

  class AddBar < ActiveRecord::Migration

    set_lock_timeout 10

    def change
      create_table :bar do |t|
        t.timestamps
      end
    end
  end

Additionally, if you have not set a default lock timeout, you can use this to set a timeout for a particular migration.

disable_ddl_transaction!

If you use disable_ddl_transaction!, no lock timeout will occur

  class AddMonkey < ActiveRecord::Migration

    disable_ddl_transaction!

    def change
      create_table :monkey do |t|
        t.timestamps
      end
    end
  end

Running the specs

To run the specs you must have PostgreSQL installed. Create a database called migration_lock_timeout_test and set the environment variables POSTGRES_DB_USERNAME and POSTGRES_DB_PASSWORD then run rspec

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/procore/migration-lock-timeout. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

About Procore

Migration Lock Timeout is maintained by Procore Technologies.

Procore - building the software that builds the world.

Learn more about the #1 most widely used construction management software at procore.com