My Rails application uses the inherited_resources gem. I am currently trying to speed it up to be able to handle a much larger data set. So I went forward (with the help of the Bullet gem) to use eager loading where it would prove helpful. Within inherited_resources it looks something like this:
def collection
my_widgets ||= end_of_association_chain.includes(:association_one, :association_two, :association_three, :association_four)
@widgets = case params[:filter]
when nil then my_widgets.all
when 'old' then my_widgets.old
when 'new' then my_widgets.new
end
@final_collection
end
The new code is .includes(:association_one, :association_two, :association_three, :association_four)
This simple change sped up my loadtime in the logs by about 5 times for my test huge database. However, the browser would just sit there, blank. Nothing. With the chrome loading icon going.
When I kill the server in the Terminal, I get this rather unique error:
ERROR ThreadError: Attempt to unlock a mutex which is locked by another thread
Backtrace at the bottom.
I have already attempted the solution discussed in the top answer to this question: How can I serve requests concurrently with Rails 4? , with the following:
#config/environments/development.rb
config.cache_classes = false
config.eager_load = true
config.allow_concurrency=true
What am I missing here? Why does simply adding these associations into eager loading, which significantly speeds up things behind the scenes, lend me an unresponsive browser with this ThreadError?
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/lock.rb:22:in `unlock'
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/lock.rb:22:in `ensure in call'
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/lock.rb:23:in `call'
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/content_length.rb:15:in `call'
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/handler/webrick.rb:88:in `service'
/Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'
/Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/handler/webrick.rb:48:in `shutdown': undefined method `shutdown' for nil:NilClass (NoMethodError)
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:280:in `block in start'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:206:in `call'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:206:in `join'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:206:in `block (2 levels) in start'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:206:in `each'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:206:in `block in start'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:32:in `start'
from /Users/johndoeuser/.rvm/rubies/ruby-2.2.1/lib/ruby/2.2.0/webrick/server.rb:162:in `start'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/handler/webrick.rb:34:in `run'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:286:in `start'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands/server.rb:80:in `start'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:80:in `block in server'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `tap'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `server'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /Users/johndoeuser/.rvm/gems/ruby-2.2.1/gems/railties-4.2.6/lib/rails/commands.rb:17:in `'
from bin/rails:4:in `require'
from bin/rails:4:in `'
edit: I am starting to wonder if this is less of a thread error than my dataset being too large for eager loading, is there a threshold where you are eager loading so many objects that, while it loads quickly in the terminal, the browser just sits there forever?
Is switching from WEBrick to Puma an option? I had a application that required concurrent requests. I was getting the error you described:
ERROR ThreadError: Attempt to unlock a mutex which is locked by another thread
Switching to Puma solved that problem right out of the box.