rake cron job

automatically run every minute

vi /etc/crontab

* * * * * root cd /var/www/data.tangentenergy.com/current && /usr/local/bin/rake RAILS_ENV=production poll_pjm_unack > /tmp/pjm_unack

set up rake task

vi /rails-app/current/lib/tasks/my.rake

desc "scrap external data"
task :poll_events => :environment do
  ExternalData.poll_events
end