Class: OnlineMigrations::BackgroundMigrations::Scheduler

Inherits:

Object

• Object
• OnlineMigrations::BackgroundMigrations::Scheduler

Defined in:

lib/online_migrations/background_migrations/scheduler.rb

Overview

Class responsible for scheduling background migrations. It selects runnable background migrations and runs them one step (one batch) at a time. A migration is considered runnable if it is not completed and the time interval between successive runs has passed.

Scheduler should be configured to run periodically, for example, via cron.

Examples:

Run via whenever

# add this to schedule.rb
every 1.minute do
  runner "OnlineMigrations.run_background_migrations"
end

Class Method Summary

• .run ⇒ Object

Instance Method Summary

• #run ⇒ Object

  Runs Scheduler.

Class Method Details

.run ⇒ Object

# File 'lib/online_migrations/background_migrations/scheduler.rb', line 18

def self.run
  new.run
end

Instance Method Details

#run ⇒ Object

Runs Scheduler

# File 'lib/online_migrations/background_migrations/scheduler.rb', line 23

def run
  active_migrations = Migration.runnable.active.queue_order
  runnable_migrations = active_migrations.select(&:interval_elapsed?)

  runnable_migrations.each do |migration|
    run_migration_job(migration)
  end
end