Production Rake Tasks Don't Recognize My Models

Question

When I was running Heroku Bamboo, this was never a problem. Now, on Cedar, I get errors whenever I try to access my models from within a rake task on the server. This happens with rake db:seed, a standard rake task, as well as my own custom built tasks that explicitly include :environment. I even do so redundantly:

namespace :db do
  desc "Update db"
  task :new_seed => :environment do
    require './Scraped_Data/Games/code/column-headers.rb'
    require 'csv'
    require 'net/http'
    require './config/environment.rb'

    # code here...

  end
end

I can't find any mention of this issue elsewhere, and all of these tasks run perfectly in development. Thanks for any insights, and here is the full error message rake tasks spit out as soon as they encounter a model of mine on Heroku:

rake aborted!
uninitialized constant Object::Movie
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/ext/module.rb:36:in `const_missing'
/app/lib/tasks/new_seed.rake:187:in `block in load_scraped_data'
/app/vendor/bundle/ruby/1.9.1/gems/rest-open-uri-1.0.0/lib/rest-open-uri.rb:37:in `open'
/app/vendor/bundle/ruby/1.9.1/gems/rest-open-uri-1.0.0/lib/rest-open-uri.rb:37:in `open'
/app/lib/tasks/new_seed.rake:148:in `load_scraped_data'
/app/lib/tasks/new_seed.rake:550:in `block (2 levels) in <top (required)>'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/usr/local/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/app/vendor/bundle/ruby/1.9.1/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/app/vendor/bundle/ruby/1.9.1/bin/rake:19:in `load'
/app/vendor/bundle/ruby/1.9.1/bin/rake:19:in `<main>'
Tasks: TOP => db:new_seed

Lodged

I suspect this is failing for a different reason.. Specifically if you run "heroku run console" can you load "Movie" there? – Jeramie

Yes, I can. I have no problem accessing all my models from the console. I just re-checked and Movie works fine from heroku run console. – Lodged

I had threadsafe! = true configured in my production environment. This caused the issue. – Lodged

Any idea why this might happen. I have a similar problem @ https://mcmap.net/q/1475972/-rake-paperclip-refresh-not-working-on-heroku/158285 – Elliott

It probably has to do with the fact that db manipulations aren't atomic, and thus aren't threadsafe operations. Obviously they can be made threadsafe with locks and such, as that's how multiple servers can touch the same db's, but I'm guessing rails abstracts that bit away but fails to enable the behavior in a rake task. – Lodged

Helped removing threadsafe! from my environment config used on Heroku. Thank you Trespassers W – Dagny

Answer 1

By default threadsafe set dependency_loading = false
If you want to enable threadsafe in your application and access to your models in your task, you'll need to load it.

# Enable threaded mode
config.threadsafe!
config.dependency_loading = true if $rails_rake_task

Ref.: http://nowhereman.github.com/how-to/rails_thread_safe/

Hope this help!

Kloster

$rails_rake_task is no longer defined in recent versions of rake or rails, but you can still manually set $rails_rake_task = true in your Rakefile. – Chian

Answer 2

I had threadsafe! = true configured in my production environment at config/environments/production.rb

Disabling this solves the problem.

The answer found here: rake aborted! uninitialized constant Object::Country, why can't see model? gives some more explanation and other workaround options (particularly the last link)

Lodged