How to get asset caching working - ruby-on-rails

Question

I am trying to upgrade to cedar / asset pipeline and am stuggling with something.
Everything renders fine, but my app seems noticeably slower. Looking thorugh my logs I see tons of items like these:
2012-03-15T17:03:02+00:00 app[web.1]: cache: [GET
/assets/application.js] miss 2012-03-15T17:03:02+00:00 app[web.1]:
cache: [GET /assets/down_arrow.gif] miss 2012-03-15T17:03:02+00:00
app[web.1]: cache: [GET /assets/application.css] miss
I would expect these to be hits -- right?
My production.rb
config.cache_classes = true
# Full error reports are disabled and caching is turned on
config.consider_all_requests_local = false
config.action_controller.perform_caching = true
# For nginx:
config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect'
# I also tried these
# config.action_dispatch.x_sendfile_header = "X-Sendfile"
# config.action_dispatch.x_sendfile_header = nil
config.cache_store = :dalli_store
My application.rb
...
config.assets.enabled = true
# Version of your assets, change this if you want to expire all your assets
config.assets.version = '1.0'
config.assets.initialize_on_precompile = false
config.active_support.deprecation = :log
Note: that assets:precompile works fine on deploy:
-----> Preparing app for Rails asset pipeline
Running: rake assets:precompile
-----> Rails plugin injection
Injecting rails_log_stdout
Injecting rails3_serve_static_assets
Thanks! Let me know if you need additional information

Answer 1

you probably missed one of the many asset-pipeline configurations. have a look at my production.rb file:
HamburgOnRuby::Application.configure do
# Settings specified here will take precedence over those in config/application.rb
# Code is not reloaded between requests
config.cache_classes = true
# Full error reports are disabled and caching is turned on
config.consider_all_requests_local = false
config.action_controller.perform_caching = true
# Disable Rails's static asset server (Apache or nginx will already do this)
config.serve_static_assets = false
# Compress JavaScripts and CSS
config.assets.compress = true
# Don't fallback to assets pipeline if a precompiled asset is missed
# config.assets.compile = false
# Generate digests for assets URLs
config.assets.digest = true
# Compress both stylesheets and JavaScripts
config.assets.js_compressor = :uglifier
config.assets.css_compressor = :scss
# Defaults to Rails.root.join("public/assets")
# config.assets.manifest = YOUR_PATH
# Specifies the header that your server uses for sending files
# config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache
# config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx
config.action_dispatch.x_sendfile_header = nil # http://devcenter.heroku.com/articles/rails31_heroku_cedar#the_asset_pipeline
# Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
# config.force_ssl = true
# See everything in the log (default is :info)
# config.log_level = :debug
# Use a different logger for distributed setups
# config.logger = SyslogLogger.new
# Use a different cache store in production
# config.cache_store = :mem_cache_store
# Enable serving of images, stylesheets, and JavaScripts from an asset server
# config.action_controller.asset_host = "http://assets.example.com"
# Precompile additional assets (application.js, application.css, and all non-JS/CSS are already added)
config.assets.precompile += %w( active_admin.js active_admin.css )
# Disable delivery errors, bad email addresses will be ignored
config.action_mailer.raise_delivery_errors = true
config.action_mailer.smtp_settings = {
:address => "smtp.sendgrid.net",
:port => "25",
:authentication => :plain,
:user_name => ENV['SENDGRID_USERNAME'],
:password => ENV['SENDGRID_PASSWORD'],
:domain => ENV['SENDGRID_DOMAIN']
}
# Enable threaded mode
# config.threadsafe!
# Enable locale fallbacks for I18n (makes lookups for any locale fall back to
# the I18n.default_locale when a translation can not be found)
config.i18n.fallbacks = true
# Send deprecation notices to registered listeners
config.active_support.deprecation = :notify
# Set the default host for production
config.default_host = 'onruby.de'
end

Answer 2

I raised a support ticket with heroku and here was there response:
I'd give this a shot:
http://jackchu.com/blog/2011/09/20/rails-asset-pipeline-content-delivery-networks-and-rack-cache/
Recent investigations Rack::Cache and memcached/dalli seems to be
broken in Rails 3.1+.
That seemed to do the trick. I look forward to the interaction between Rack::Cache and dalli to be fixed, but in the mean time I will follow #jackchu approach