Ruby-on-rails 诊断视图渲染慢的原因

Diagnosing the cause of slow view rendering

提问by Abram

I'm not sure when this started, but something unusual is happening in my app (run locally on a development machine). Suddenly I am seeing messages like:

我不确定这是什么时候开始的，但是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）。突然我看到这样的消息：

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.

如您所见，加载主页需要 3 秒（一个相对简单的页面）...我们不是在谈论重新加载硬页面...只需从另一个页面再次单击“主页”链接即可。

Not really sure where to start here, but this is my application.rb:

不确定从哪里开始，但这是我的 application.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

...and dev.rb:

...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

EDIT:

编辑：

OK, Here is what I am seeing on new relic. Doesn't really help me though. Any thoughts?

好的，这是我在新遗物上看到的。虽然对我没有真正的帮助。有什么想法吗？

Oh and what I learned from Chrome timeline:

哦，我从 Chrome 时间线中学到了什么：

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

By the way I disabled the quiet_assets gem to see what I could discover in the terminal.. again.. not helpful:

顺便说一下，我禁用了 quiet_assets gem 以查看我可以在终端中发现的内容......再次......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)

By the way, as per a suggestion on reddit I precompiled assets and ran the server. Seeing fantastic speeds:

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。看到惊人的速度：

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 not sure this is providing any help or not but the major delay is happening between these two lines of code in the stack:

好的，不确定这是否提供任何帮助，但主要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

MAJOR DELAY

主要延迟

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

回答by Abram

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

好的，我想通了（终于）。在不改变我的任何实际资产的情况下，我现在看到这是发展：

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 = trueinside of development.rb. Setting this to falseresolves the problem.

事实证明延迟是由config.assets.debug = truedevelopment.rb 内部引起的。设置它来false解决问题。

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.

看起来 Rails 核心团队讨论过默认关闭此功能，但最终决定反对这个想法。将来，我很乐意看到他们在 development.rb 的评论部分添加一些内容，以提示用户可能会出现严重延迟。

May I suggest the following:

我可以提出以下建议：

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

Great, they heard me muttering and updated rails!

太好了，他们听到了我的喃喃自语和更新的 rails！

回答by Anton K

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

在 rails 4.1+ 中也出现了同样的问题。亚伯兰的回答只是部分完整。

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

您可以离开，config.assets.debug = true但应禁用新的资产验证功能

# 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.debugdisabled only works because it compiles assets once and assets are verified once. Assets verification is where the most of the time is spent.

config.assets.debug禁用的解决方案仅有效，因为它编译资产一次并且资产验证一次。资产验证是花费最多时间的地方。

回答by Sean O'Hara

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.

如果您来自 rails 3.2.13 请注意，很多人都遇到过这个问题，恢复到 3.2.12 似乎可以解决它。你可以在 github 上找到更多信息。

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

在我的情况下，禁用会config.assets.debug稍微加快速度，但恢复到 3.2.12 会降低请求时间从大约 4 秒减少到大约 250 毫秒。

回答by DaveStephens

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.

看看NewRelic.com- 它需要花费，但免费试用将使您能够完全剖析您的应用程序并找出任何瓶颈所在。

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.

除了 New Relic 运行通常的检查之外，例如它是什么时候开始的？你最近有什么变化？您是否升级了 Rails 和/或任何 gem？从源代码管理中检查并运行一些以前的版本，然后尝试找出导致问题的具体提交。

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.

所有浏览器都会出现这个问题吗？尝试启动 Chrome 时间线查看器，您将能够查看浏览器是否卡在特定的 JavaScript 片段上。

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

还尝试将您的本地开发 Web 服务器切换到瘦，问题是否仍然存在？

Good luck!

祝你好运！

回答by jemminger

Are you on OSX and serving via .local?

您是否使用 OSX 并通过 .local 提供服务？

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

如果是这样，我会抛出我在评论中找到的帖子作为解决方案：
子域约束（Rails 3）使本地服务器（瘦）太慢