Caching caches_action fragmens in Memcache and assets in the file system - ruby-on-rails

Question

Using Rails 3.1.1 on Heroku, Dalli gem and Memcachier.
I am trying to troubleshoot an issue where keys disappear from Memcachier, in order to do this I would like to make sure that only the content from my caches_action will be cached in the memcache. I would like my assets (jpg's etc) to be cached elsewhere.
I believe it is the same issue as this question but when I do the same, i.e. adding
config.action_dispatch.rack_cache = {
:metastore => Dalli::Client.new,
:entitystore => 'file:tmp/cache/rack/body',
:allow_reload => false
}
to my production.rb, it doesn't really seem to do anything.
My production.rb in full:
MyDemoApp::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 = true
# Compress JavaScripts and CSS
config.assets.compress = true
# Don't fallback to assets pipeline if a precompiled asset is missed
config.assets.compile = true
# Generate digests for assets URLs
config.assets.digest = true
# 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
# 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
# Prepend all log lines with the following tags
# config.log_tags = [ :subdomain, :uuid ]
# Use a different logger for distributed setups
# config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
# Use a different cache store in production
config.cache_store = :dalli_store
config.action_dispatch.rack_cache = {
:metastore => Dalli::Client.new,
:entitystore => 'file:tmp/cache/rack/body',
:allow_reload => false
}
# Set expire header of 30 days for static files
config.static_cache_control = "public, max-age=2592000"
# 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( search.js )
# Disable delivery errors, bad email addresses will be ignored
# config.action_mailer.raise_delivery_errors = false
# 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
end
Caching assets work fine (get cache fresh-responses) and caching actions like this:
caches_action :show, :layout => false, :expires_in => 3.days
Also creates a cached entry in Rails cache (although they disappear after a while).
My question now is: How can I, if possible, do so that only my caches_action fragments end up in my Memcache (and not my assets)?
A bonus question would be, do you see anything out of the ordinary in my production.rb?

Answer 1

I use the gem 'asset_sync' to move all my assets out to Amamzon S3
See Instructions here
You get three advantages:
Your assets are served from Amazon so the page loads faster for the
user
Your slug size on Heroku is smaller and is supposed to be more
performant
Your assets will no longer be in memecahce
All my assets cost me about 20cents every three month to host on Amamzon