kotovalexarian-likes-github/rails--rails
1
0
Fork 0
mirror of https://github.com/rails/rails.git synced 2022-11-09 12:12:34 -05:00
Code Releases Activity

Merge pull request #21188 from derekprior/dp-asset-host-docs

Browse source 
Update info on browser connection limits [ci skip]
This commit is contained in:
Rafael Mendonça França 2015-08-10 16:53:08 -03:00
commit c14c798298
1 changed files with 18 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
actionview/lib/action_view/helpers/asset_url_helper.rb
View file

@ -31,26 +31,33 @@ module ActionView
# stylesheet_link_tag("application")
# # => <link href="http://assets.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# Browsers typically open at most two simultaneous connections to a single
# host, which means your assets often have to wait for other assets to finish
# downloading. You can alleviate this by using a <tt>%d</tt> wildcard in the
# +asset_host+. For example, "assets%d.example.com". If that wildcard is
# present Rails distributes asset requests among the corresponding four hosts
# "assets0.example.com", ..., "assets3.example.com". With this trick browsers
# will open eight simultaneous connections rather than two.
# Browsers open a limited number of simulataneous connections to a single
# host. The exact number varies by browser and version. This limit may cause
# some asset downloads to wait for previous assets to finish before they can
# begin. You can use the <tt>%d</tt> wildcard in the +asset_host+ to
# distribute the requests over four hosts. For example,
# <tt>assets%d.example.com<tt> will spread the asset requests over
# "assets0.example.com", ..., "assets3.example.com".
#
# image_tag("rails.png")
# # => <img alt="Rails" src="http://assets0.example.com/assets/rails.png" />
# stylesheet_link_tag("application")
# # => <link href="http://assets2.example.com/assets/application.css" media="screen" rel="stylesheet" />
#
# To do this, you can either setup four actual hosts, or you can use wildcard
# DNS to CNAME the wildcard to a single asset host. You can read more about
# setting up your DNS CNAME records from your ISP.
# This may improve the asset loading performance of your application.
# It is also possible the combination of additional connection overhead
# (DNS, SSL) and the overall browser connection limits may result in this
# solution being slower. You should be sure to measure your actual
# performance across targeted browers both before and after this change.
#
# To implement the corresponding hosts you can either setup four actual
# hosts or use wildcard DNS to CNAME the wilcard to a single asset host.
# You can read more about setting up your DNS CNAME records from your ISP.
#
# Note: This is purely a browser performance optimization and is not meant
# for server load balancing. See http://www.die.net/musings/page_load_time/
# for background.
# for background and http://www.browserscope.org/?category=network for
# connection limit data.
#
# Alternatively, you can exert more control over the asset host by setting
# +asset_host+ to a proc like this: