From 77c6ba9fcd1494fbc9275217700ad3f0f0a23b0f Mon Sep 17 00:00:00 2001 From: miloops Date: Mon, 3 Nov 2008 12:58:38 -0300 Subject: Added RJS, memory leaks and plugins chapters to Debugging Rails Applications guide. Generated Guides. --- .../guides/html/debugging_rails_applications.html | 152 ++++++++++++++++++++- railties/doc/guides/html/migrations.html | 2 +- .../guides/source/debugging_rails_applications.txt | 104 ++++++++++++++ 3 files changed, 255 insertions(+), 3 deletions(-) diff --git a/railties/doc/guides/html/debugging_rails_applications.html b/railties/doc/guides/html/debugging_rails_applications.html index bf1e442d59..0fdc1b0a1f 100644 --- a/railties/doc/guides/html/debugging_rails_applications.html +++ b/railties/doc/guides/html/debugging_rails_applications.html @@ -208,6 +208,8 @@ ul#navMain {
  • inspect
    • +
  • Debugging Javascript
    • +
  • @@ -253,6 +255,19 @@ ul#navMain {
  • + Debugging Memory Leaks + +
    • +
  • + Plugins for Debugging +
    • +
  • References
  • @@ -397,6 +412,32 @@ http://www.gnu.org/software/src-highlite --> Title: Rails debugging guide +

    1.4. Debugging Javascript

    +

    Rails has built-in support to debug RJS, to active it, set ActionView::Base.debug_rjs to true, this will specify whether RJS responses should be wrapped in a try/catch block that alert()s the caught exception (and then re-raises it).

    +

    To enable it, add the following in the Rails::Initializer do |config| block inside environment.rb:

    +
    +
    +
    config.action_view[:debug_rjs] = true
+
    +

    Or, at any time, setting ActionView::Base.debug_rjs to true:

    +
    +
    +
    ActionView::Base.debug_rjs = true
+
    +
    + + + +
    +Tip +For more information on debugging javascript refer to Firebug, the popular debugger for Firefox.
    +

    2. The Logger

    @@ -978,7 +1019,104 @@ set forcestep set listsize 25
    -

    4. References

    +

    4. Debugging Memory Leaks

    +
    +

    A Ruby application (on Rails or not), can leak memory whether in the Ruby code but also in the C code.

    +

    In this section, you will learn how to find and fix this leaks by using Bleak House and Valgrind debugging tools.

    +

    4.1. Bleak House

    +

    Bleak House is a library for finding memory leaks.

    +

    If a Ruby object does not go out of scope, the Ruby Garbage Collector won't sweep it since it is referenced somewhere, this leaks can grow slowly and your application will consume more and more memory gradually affecting the overall system performance. This tool will help you find leaks on the Ruby heap.

    +

    To install it run:

    +
    +
    +
    sudo gem install bleak_house
    +
    +

    Then setup you application for profiling, add the following at the bottom of config/environment.rb:

    +
    +
    +
    require 'bleak_house' if ENV['BLEAK_HOUSE']
+
    +

    Start a server instance with Bleak House integration:

    +
    +
    +
    RAILS_ENV=production BLEAK_HOUSE=1 ruby-bleak-house ./script/server
    +
    +

    Make sure to run a couple hundred requests to get better data samples, hit CTRL-C. The server will stop and Bleak House will produce a dumpfile in /tmp:

    +
    +
    +
    ** BleakHouse: working...
+** BleakHouse: complete
+** Bleakhouse: run 'bleak /tmp/bleak.5979.0.dump' to analyze.
+
    +

    To analyze it, just run the listed command. The top 20 leakiest lines will be listed:

    +
    +
    +
      191691 total objects
+  Final heap size 191691 filled, 220961 free
+  Displaying top 20 most common line/class pairs
+  89513 __null__:__null__:__node__
+  41438 __null__:__null__:String
+  2348 /opt/local//lib/ruby/site_ruby/1.8/rubygems/specification.rb:557:Array
+  1508 /opt/local//lib/ruby/gems/1.8/specifications/gettext-1.90.0.gemspec:14:String
+  1021 /opt/local//lib/ruby/gems/1.8/specifications/heel-0.2.0.gemspec:14:String
+   951 /opt/local//lib/ruby/site_ruby/1.8/rubygems/version.rb:111:String
+   935 /opt/local//lib/ruby/site_ruby/1.8/rubygems/specification.rb:557:String
+   834 /opt/local//lib/ruby/site_ruby/1.8/rubygems/version.rb:146:Array
+  ...
+
    +

    This way you can find where you application is leaking memory and fix it.

    +

    If BleakHouse doesn't report any heap growth but you still have memory growth, you might have a broken C extension, or real leak in the interpreter, try using Valgrind.

    +

    4.2. Valgrind

    +

    Valgrind is a Linux (only works on Linux) application for detecting C-based memory leaks and race conditions.

    +

    There are Valgrind tools that can automatically detect many memory management and threading bugs, and profile your programs in detail. For example, a C extension in the interpreter calls malloc() but is doesn't properly call free(), this memory won't be available until the app terminates.

    +

    For further information on how to install and using with Ruby, refer to the Valgrind and Ruby Evan Weaver's article.

    +
    +

    5. Plugins for Debugging

    +
    +

    To make life easier Rails offer plugins, some of them will help you to find errors and debug your application. Here is a list of useful plugins for debugging:

    +
      +
    • +

      +Footnotes: Every Rails page has footnotes that link give request information and link back to your source via TextMate. +

      +
      • +
    • +

      +Query Trace: Adds query origin tracing to your logs. +

      +
      • +
    • +

      +Query Stats: A Rails plugin to track database queries. +

      +
      • +
    • +

      +Query Reviewer: This rails plugin not only runs "EXPLAIN" before each of your select queries in development, but provides a small DIV in the rendered output of each page with the summary of query warnings that it analyzed. +

      +
      • +
    • +

      +Exception Notifier: Provides a mailer object and a default set of templates for sending email notifications when errors occur in a Rails application. +

      +
      • +
    • +

      +Exception Logger: Logs your Rails exceptions in the database and provides a funky web interface to manage them. +

      +
      • +
    +
    +

    6. References

    -

    5. Changelog

    +

    7. Changelog

    Lighthouse ticket

    • +November 3, 2008: Added RJS, memory leaks and plugins chapters by Emilio Tagua +

      +
      • +
    • +

      October 19, 2008: Copy editing pass by Mike Gunderloy

      • diff --git a/railties/doc/guides/html/migrations.html b/railties/doc/guides/html/migrations.html index fd466d3a02..5d0f450634 100644 --- a/railties/doc/guides/html/migrations.html +++ b/railties/doc/guides/html/migrations.html @@ -717,7 +717,7 @@ version is the numerical prefix on the migration's filename. For example to migr 
      rake db:rollback STEP=3
    -

    will run the down method fron the last 3 migrations.

    +

    will run the down method from the last 3 migrations.

    The db:migrate:redo task is a shortcut for doing a rollback and then migrating back up again. As with the db:rollback task you can use the STEP parameter if you need to go more than one version back, for example

    diff --git a/railties/doc/guides/source/debugging_rails_applications.txt b/railties/doc/guides/source/debugging_rails_applications.txt index 24eb0c0431..7271a05666 100644 --- a/railties/doc/guides/source/debugging_rails_applications.txt +++ b/railties/doc/guides/source/debugging_rails_applications.txt @@ -101,6 +101,27 @@ Will be rendered as follows: Title: Rails debugging guide ---------------------------------------------------------------------------- +=== Debugging Javascript + +Rails has built-in support to debug RJS, to active it, set `ActionView::Base.debug_rjs` to _true_, this will specify whether RJS responses should be wrapped in a try/catch block that alert()s the caught exception (and then re-raises it). + +To enable it, add the following in the `Rails::Initializer do |config|` block inside +environment.rb+: + +[source, ruby] +---------------------------------------------------------------------------- +config.action_view[:debug_rjs] = true +---------------------------------------------------------------------------- + +Or, at any time, setting `ActionView::Base.debug_rjs` to _true_: + +[source, ruby] +---------------------------------------------------------------------------- +ActionView::Base.debug_rjs = true +---------------------------------------------------------------------------- + +[TIP] +For more information on debugging javascript refer to link:http://getfirebug.com/[Firebug], the popular debugger for Firefox. + == The Logger It can also be useful to save information to log files at runtime. Rails maintains a separate log file for each runtime environment. @@ -617,6 +638,87 @@ set forcestep set listsize 25 ---------------------------------------------------------------------------- +== Debugging Memory Leaks + +A Ruby application (on Rails or not), can leak memory whether in the Ruby code but also in the C code. + +In this section, you will learn how to find and fix this leaks by using Bleak House and Valgrind debugging tools. + +=== Bleak House + +link:http://github.com/fauna/bleak_house/tree/master[Bleak House] is a library for finding memory leaks. + +If a Ruby object does not go out of scope, the Ruby Garbage Collector won't sweep it since it is referenced somewhere, this leaks can grow slowly and your application will consume more and more memory gradually affecting the overall system performance. This tool will help you find leaks on the Ruby heap. + +To install it run: + +---------------------------------------------------------------------------- +sudo gem install bleak_house +---------------------------------------------------------------------------- + +Then setup you application for profiling, add the following at the bottom of config/environment.rb: + +[source, ruby] +---------------------------------------------------------------------------- +require 'bleak_house' if ENV['BLEAK_HOUSE'] +---------------------------------------------------------------------------- + +Start a server instance with Bleak House integration: + +---------------------------------------------------------------------------- +RAILS_ENV=production BLEAK_HOUSE=1 ruby-bleak-house ./script/server +---------------------------------------------------------------------------- + +Make sure to run a couple hundred requests to get better data samples, hit `CTRL-C`. The server will stop and Bleak House will produce a dumpfile in `/tmp`: + +[source, log] +---------------------------------------------------------------------------- +** BleakHouse: working... +** BleakHouse: complete +** Bleakhouse: run 'bleak /tmp/bleak.5979.0.dump' to analyze. +---------------------------------------------------------------------------- + +To analyze it, just run the listed command. The top 20 leakiest lines will be listed: + +[source, log] +---------------------------------------------------------------------------- + 191691 total objects + Final heap size 191691 filled, 220961 free + Displaying top 20 most common line/class pairs + 89513 __null__:__null__:__node__ + 41438 __null__:__null__:String + 2348 /opt/local//lib/ruby/site_ruby/1.8/rubygems/specification.rb:557:Array + 1508 /opt/local//lib/ruby/gems/1.8/specifications/gettext-1.90.0.gemspec:14:String + 1021 /opt/local//lib/ruby/gems/1.8/specifications/heel-0.2.0.gemspec:14:String + 951 /opt/local//lib/ruby/site_ruby/1.8/rubygems/version.rb:111:String + 935 /opt/local//lib/ruby/site_ruby/1.8/rubygems/specification.rb:557:String + 834 /opt/local//lib/ruby/site_ruby/1.8/rubygems/version.rb:146:Array + ... +---------------------------------------------------------------------------- + +This way you can find where you application is leaking memory and fix it. + +If link:http://github.com/fauna/bleak_house/tree/master[BleakHouse] doesn't report any heap growth but you still have memory growth, you might have a broken C extension, or real leak in the interpreter, try using Valgrind. + +=== Valgrind + +link:http://valgrind.org/[Valgrind] is a Linux (only works on Linux) application for detecting C-based memory leaks and race conditions. + +There are Valgrind tools that can automatically detect many memory management and threading bugs, and profile your programs in detail. For example, a C extension in the interpreter calls `malloc()` but is doesn't properly call `free()`, this memory won't be available until the app terminates. + +For further information on how to install and using with Ruby, refer to the link:http://blog.evanweaver.com/articles/2008/02/05/valgrind-and-ruby/[Valgrind and Ruby Evan Weaver's article]. + +== Plugins for Debugging + +To make life easier Rails offer plugins, some of them will help you to find errors and debug your application. Here is a list of useful plugins for debugging: + +* link:http://github.com/drnic/rails-footnotes/tree/master[Footnotes]: Every Rails page has footnotes that link give request information and link back to your source via TextMate. +* link:http://github.com/ntalbott/query_trace/tree/master[Query Trace]: Adds query origin tracing to your logs. +* link:http://github.com/dan-manges/query_stats/tree/master[Query Stats]: A Rails plugin to track database queries. +* link:http://code.google.com/p/query-reviewer/[Query Reviewer]: This rails plugin not only runs "EXPLAIN" before each of your select queries in development, but provides a small DIV in the rendered output of each page with the summary of query warnings that it analyzed. +* link:http://github.com/rails/exception_notification/tree/master[Exception Notifier]: Provides a mailer object and a default set of templates for sending email notifications when errors occur in a Rails application. +* link:http://github.com/defunkt/exception_logger/tree/master[Exception Logger]: Logs your Rails exceptions in the database and provides a funky web interface to manage them. + == References * link:http://www.datanoise.com/ruby-debug[ruby-debug Homepage] @@ -628,10 +730,12 @@ set listsize 25 * link:http://bashdb.sourceforge.net/ruby-debug.html[Debugging with ruby-debug] * link:http://cheat.errtheblog.com/s/rdebug/[ruby-debug cheat sheet] * link:http://wiki.rubyonrails.org/rails/pages/HowtoConfigureLogging[Ruby on Rails Wiki: How to Configure Logging] +* link:http://blog.evanweaver.com/files/doc/fauna/bleak_house/files/README.html[Bleak House Documentation] == Changelog == http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/5[Lighthouse ticket] +* November 3, 2008: Added RJS, memory leaks and plugins chapters by link:../authors.html#miloops[Emilio Tagua] * October 19, 2008: Copy editing pass by link:../authors.html#mgunderloy[Mike Gunderloy] * September 16, 2008: initial version by link:../authors.html#miloops[Emilio Tagua] -- cgit v1.2.3