视图呈现缓慢的原因诊断

我不确定这是什么时候开始的,但是在我的应用程序中发生了一些不寻常的事情(在开发机器上本地运行)。突然间,我看到了这样的信息:

Started GET "/" for 127.0.0.1 at 2013-03-10 12:10:24 +1300
Processing by PagesController#home as HTML
Rendered pages/home.html.erb within layouts/application (2.4ms)
Completed 200 OK in 3242ms (Views: 3241.4ms | ActiveRecord: 0.0ms)

As you can see 3 seconds to load the home page (a relatively simple page) ... We're not talking a hard page reload .. just clicking on the "home" link again from another page.

不知道从哪里开始,但这是我的应用程序.rb:

#config/boot.rb is loaded
require File.expand_path('../boot', __FILE__)


require 'rails/all'


if defined?(Bundler)
Bundler.require(*Rails.groups(:assets => %w(development test)))
end


module Goodsounds
class Application < Rails::Application
config.encoding = "utf-8"
config.filter_parameters += [:password]
config.assets.initialize_on_precompile = false
config.assets.enabled = true
config.action_controller.assets_dir = "#{File.dirname(File.dirname(__FILE__))}/public"
config.assets.version = '1.0'
config.autoload_paths += Dir["#{Rails.root}/lib/modules"]
config.assets.paths += Dir["#{Rails.root}/app/assets/fonts/*"]
config.assets.precompile += %w( .svg .eot .woff .ttf )
end
end

... 和 dev.rb:

Goodsounds::Application.configure do
# Settings specified here will take precedence over those in config/application.rb
Paperclip.options[:command_path] = "/usr/bin/"


config.action_mailer.default_url_options = { :host => 'localhost:3000' }


config.action_mailer.raise_delivery_errors = true


# set delivery method to :smtp, :sendmail or :test
config.action_mailer.delivery_method = :smtp


# these options are only needed if you choose smtp delivery


config.action_mailer.smtp_settings = { :address => "localhost", :port => 1025 }


# In the development environment your application's code is reloaded on
# every request. This slows down response time but is perfect for development
# since you don't have to restart the web server when you make code changes.
config.cache_classes = false


# Log error messages when you accidentally call methods on nil.
config.whiny_nils = true


# Show full error reports and disable caching
config.consider_all_requests_local       = true
config.action_controller.perform_caching = false


# Print deprecation notices to the Rails logger
config.active_support.deprecation = :log


# Only use best-standards-support built into browsers
config.action_dispatch.best_standards_support = :builtin


# Raise exception on mass assignment protection for Active Record models
config.active_re
cord.mass_assignment_sanitizer = :strict


# Log the query plan for queries taking more than this (works
# with SQLite, MySQL, and PostgreSQL)
config.active_record.auto_explain_threshold_in_seconds = 0.5


# Do not compress assets
config.assets.compress = false


# Expands the lines which load the assets
config.assets.debug = true
end

编辑:

好吧,这是我在新纪念品上看到的。不过对我没什么帮助。有什么想法吗?

enter image description here

enter image description here

哦,还有我从 Chrome 时间轴中学到的:

Send Request - Details
Duration    0 (at 655 ms)
Resource    localhost
Request Method  GET


Receive Response - Details
Duration    0.043 ms (at 4.17 s)
Resource    localhost
Status Code 200
MIME Type   text/html


Receive Data - Details
Duration    176.329 ms (at 4.17 s)
Self Time   7.037 ms
CPU Time    176.329 ms
Aggregated Time 061.194 ms114.664 ms0.471 ms0
Resource    localhost
Encoded Data Length 303 Bytes
Used Heap Size  29.1 MB (+5.7 MB)


Finish Loading - Details
Duration    0 (at 4.35 s)
Resource    localhost

顺便说一下,我禁用了 static _ asset gem 来查看我能在终端中发现什么... ... 再说一遍,没有帮助:

Started GET "/" for 127.0.0.1 at 2013-03-10 21:46:40 +1300
Processing by PagesController#home as HTML
Rendered pages/home.html.erb within layouts/application (43.4ms)
Completed 200 OK in 3501ms (Views: 3480.9ms | ActiveRecord: 19.4ms)




Started GET "/assets/dataTables/jquery.dataTables.bootstrap.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /dataTables/jquery.dataTables.bootstrap.css - 304 Not Modified (11ms)




Started GET "/assets/chosen.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /chosen.css - 304 Not Modified (5ms)




Started GET "/assets/select2.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /select2.css - 304 Not Modified (4ms)




Started GET "/assets/autocomplete.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /autocomplete.css - 304 Not Modified (1ms)




Started GET "/assets/branches.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /branches.css - 304 Not Modified (2ms)




Started GET "/assets/bubbles.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bubbles.css - 304 Not Modified (1ms)




Started GET "/assets/business_show.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /business_show.css - 304 Not Modified (1ms)




Started GET "/assets/chunkyfive_font.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /chunkyfive_font.css - 304 Not Modified (1ms)




Started GET "/assets/consumer_show.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /consumer_show.css - 304 Not Modified (2ms)




Started GET "/assets/datatable_styling.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /datatable_styling.css - 304 Not Modified (1ms)




Started GET "/assets/datepicker.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /datepicker.css - 304 Not Modified (2ms)




Started GET "/assets/devise_links.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /devise_links.css - 304 Not Modified (1ms)




Started GET "/assets/dispenser_show.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /dispenser_show.css - 304 Not Modified (1ms)




Started GET "/assets/fonts.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /fonts.css - 304 Not Modified (1ms)




Started GET "/assets/forms.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /forms.css - 304 Not Modified (2ms)




Started GET "/assets/gmaps4rails.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails.css - 304 Not Modified (1ms)




Started GET "/assets/jquery-ui-1.10.0.custom.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jquery-ui-1.10.0.custom.css - 304 Not Modified (2ms)




Started GET "/assets/jumbotrons.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jumbotrons.css - 304 Not Modified (1ms)




Started GET "/assets/layout.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /layout.css - 304 Not Modified (1ms)




Started GET "/assets/open_sans.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /open_sans.css - 304 Not Modified (2ms)




Started GET "/assets/popover.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /popover.css - 304 Not Modified (1ms)




Started GET "/assets/reviews.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /reviews.css - 304 Not Modified (1ms)




Started GET "/assets/spinner.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /spinner.css - 304 Not Modified (2ms)




Started GET "/assets/style_show.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /style_show.css - 304 Not Modified (2ms)




Started GET "/assets/style_show_reviews.css?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /style_show_reviews.css - 304 Not Modified (2ms)




Started GET "/assets/jquery.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jquery.js - 304 Not Modified (3ms)




Started GET "/assets/jquery_ujs.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jquery_ujs.js - 304 Not Modified (3ms)




Started GET "/assets/ui.custom.min.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /ui.custom.min.js - 304 Not Modified (1ms)




Started GET "/assets/bootstrap-transition.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-transition.js - 304 Not Modified (5ms)




Started GET "/assets/bootstrap-affix.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-affix.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-alert.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-alert.js - 304 Not Modified (4ms)




Started GET "/assets/bootstrap-button.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-button.js - 304 Not Modified (5ms)




Started GET "/assets/bootstrap-carousel.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-carousel.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-collapse.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-collapse.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-dropdown.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-dropdown.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-modal.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-modal.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-scrollspy.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-scrollspy.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-tab.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-tab.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap-tooltip.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-tooltip.js - 304 Not Modified (5ms)




Started GET "/assets/bootstrap-popover.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-popover.js - 304 Not Modified (52ms)




Started GET "/assets/bootstrap-typeahead.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap-typeahead.js - 304 Not Modified (3ms)




Started GET "/assets/bootstrap.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /bootstrap.js - 304 Not Modified (13ms)




Started GET "/assets/gmaps4rails/gmaps4rails.base.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails/gmaps4rails.base.js - 304 Not Modified (1ms)




Started GET "/assets/gmaps4rails/gmaps4rails.bing.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails/gmaps4rails.bing.js - 304 Not Modified (2ms)




Started GET "/assets/gmaps4rails/gmaps4rails.googlemaps.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails/gmaps4rails.googlemaps.js - 304 Not Modified (2ms)




Started GET "/assets/gmaps4rails/gmaps4rails.mapquest.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails/gmaps4rails.mapquest.js - 304 Not Modified (2ms)




Started GET "/assets/gmaps4rails/gmaps4rails.openlayers.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /gmaps4rails/gmaps4rails.openlayers.js - 304 Not Modified (2ms)




Started GET "/assets/jqueryplugins/addresspicker.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/addresspicker.js - 304 Not Modified (2ms)




Started GET "/assets/jqueryplugins/browser_detect.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/browser_detect.js - 304 Not Modified (3ms)




Started GET "/assets/jqueryplugins/charts.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/charts.js - 304 Not Modified (2ms)




Started GET "/assets/jqueryplugins/jquery.alphanumeric.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/jquery.alphanumeric.js - 304 Not Modified (1ms)




Started GET "/assets/jqueryplugins/jquery.formrestrict.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/jquery.formrestrict.js - 304 Not Modified (2ms)




Started GET "/assets/jqueryplugins/jquery.lazyload.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/jquery.lazyload.js - 304 Not Modified (1ms)




Started GET "/assets/jqueryplugins/raty.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /jqueryplugins/raty.js - 304 Not Modified (2ms)




Started GET "/assets/dataTables/jquery.dataTables.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /dataTables/jquery.dataTables.js - 304 Not Modified (13ms)




Started GET "/assets/dataTables/jquery.dataTables.bootstrap.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /dataTables/jquery.dataTables.bootstrap.js - 304 Not Modified (63ms)




Started GET "/assets/lib/abstract-chosen.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /lib/abstract-chosen.js - 304 Not Modified (12ms)




Started GET "/assets/lib/select-parser.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /lib/select-parser.js - 304 Not Modified (12ms)




Started GET "/assets/chosen.jquery.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /chosen.jquery.js - 304 Not Modified (8ms)




Started GET "/assets/chosen-jquery.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /chosen-jquery.js - 304 Not Modified (9ms)




Started GET "/assets/select2.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /select2.js - 304 Not Modified (7ms)




Started GET "/assets/highcharts.js?body=1" for 127.0.0.1 at 2013-03-10 21:46:44 +1300
Served asset /highcharts.js - 304 Not Modified (1ms)

顺便说一下,根据 reddit 上的建议,我预编译了资产并运行了服务器:

Processing by PagesController#home as HTML
Rendered pages/home.html.erb within layouts/application (1.1ms)
Completed 200 OK in 6ms (Views: 5.4ms | ActiveRecord: 0.0ms)

OK 不确定这是否提供任何帮助,但主要的延迟发生在堆栈中的这两行代码之间:

From: /home/funkdified/.rvm/gems/ruby-1.9.3-p392@goodsounds/gems/actionpack-3.2.13.rc1/lib/action_controller/metal/implicit_render.rb @ line 5 ActionController::ImplicitRender#send_action:


3: def send_action(method, *args)
4:   ret = super
=> 5:   default_render unless response_body
6:   ret
7: end


[2] pry(#<PagesController>)> next

严重延误

From: /home/funkdified/.rvm/gems/ruby-1.9.3-p392@goodsounds/gems/actionpack-3.2.13.rc1/lib/action_controller/metal/implicit_render.rb @ line 6 ActionController::ImplicitRender#send_action:


3: def send_action(method, *args)
4:   ret = super
5:   default_render unless response_body
=> 6:   ret
7: end
51470 次浏览

Take a look at NewRelic.com - it costs, but the free trial will allow you to totally dissect your application and work out where any bottlenecks are.

Aside from New Relic run through the usual checks, e.g. when did it start? What have you changed recently? Have you upgraded Rails and/or any gems? Check out and run a few previous versions from your source control and try and work out specifically which commit caused the issue.

Does the issue happen with all browsers? Try firing up the Chrome timeline viewer and you'll be able to see if the browser is getting stuck up on a particular piece of JavaScript.

Also try switching your local dev web server to thin, does the issue persist?

Good luck!

Are you on OSX and serving via .local?

If so, gonna throw the post I found in my comments as a solution:
Subdomain constraint (Rails 3) makes local server (thin) SO SLOW

Ok, I figured it out (at long last). Without changing any of my actual assets I am now seeing this is development:

Started GET "/" for 127.0.0.1 at 2013-03-11 23:14:33 +1300
Processing by PagesController#home as HTML
Rendered pages/home.html.erb within layouts/application (1.3ms)

It turns out the delay was being caused by config.assets.debug = true inside of development.rb. Setting this to false resolves the problem.

Looks like the Rails core team debated turning this off by default, but decided against the idea. In the future I'd love to see them put something in the comment section of development.rb to tip off users of the potential for significant delays.

May I suggest the following:

# Expands the lines which load the assets
# May cause significant delays in view rendering

Great, they heard me muttering and updated rails!

If you're coming from rails 3.2.13 note that a bunch of people have experienced this issue and reverting to 3.2.12 seems to resolve it. You can find more info here on github.

In my case disabling config.assets.debug sped things up a little, but reverting to 3.2.12 dropped request time from around 4 seconds to around 250ms.

The same issue has appeared for me in rails 4.1+. Abram's answer is only partially complete.

You can leave config.assets.debug = true but should disable new assets verification feature

# Adds additional error checking when serving assets at runtime.
# Checks for improperly declared sprockets dependencies.
# Raises helpful error messages.
config.assets.raise_runtime_errors = false

Solution with config.assets.debug disabled only works because it compiles assets once and assets are verified once. Assets verification is where the most of the time is spent.