今天早上，我将 rails 从 3.2.12 更新到 3.2.13，这导致我的视​​图加载出现重大延迟。 这是来自加载我的主页:

Rails 3.2.12:
Completed 200 OK in 387ms (Views: 339.0ms | ActiveRecord: 27.1ms)

Rails 3.2.13:
Completed 200 OK in 4416ms (Views: 4361.2ms | ActiveRecord: 28.7ms)

两者之间的唯一区别是提交了 Rails 版本，这当然也导致了很多其他的 gem 被更新...... 这是 Gemfile.lock 的区别:

GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (3.2.12)
-      actionpack (= 3.2.12)
-      mail (~> 2.4.4)
-    actionpack (3.2.12)
-      activemodel (= 3.2.12)
-      activesupport (= 3.2.12)
+    actionmailer (3.2.13)
+      actionpack (= 3.2.13)
+      mail (~> 2.5.3)
+    actionpack (3.2.13)
+      activemodel (= 3.2.13)
+      activesupport (= 3.2.13)
       builder (~> 3.0.0)
       erubis (~> 2.7.0)
       journey (~> 1.0.4)
@@ -14,19 +14,19 @@ GEM
       rack-cache (~> 1.2)
       rack-test (~> 0.6.1)
       sprockets (~> 2.2.1)
-    activemodel (3.2.12)
-      activesupport (= 3.2.12)
+    activemodel (3.2.13)
+      activesupport (= 3.2.13)
       builder (~> 3.0.0)
-    activerecord (3.2.12)
-      activemodel (= 3.2.12)
-      activesupport (= 3.2.12)
+    activerecord (3.2.13)
+      activemodel (= 3.2.13)
+      activesupport (= 3.2.13)
       arel (~> 3.0.2)
       tzinfo (~> 0.3.29)
-    activeresource (3.2.12)
-      activemodel (= 3.2.12)
-      activesupport (= 3.2.12)
-    activesupport (3.2.12)
-      i18n (~> 0.6)
+    activeresource (3.2.13)
+      activemodel (= 3.2.13)
+      activesupport (= 3.2.13)
+    activesupport (3.2.13)
+      i18n (= 0.6.1)
       multi_json (~> 1.0)
     airbrake (3.1.7)
       activesupport
@@ -129,7 +129,7 @@ GEM
     hashr (0.0.22)
     hike (1.2.1)
     honeypot-captcha (0.0.2)
-    i18n (0.6.4)
+    i18n (0.6.1)
     journey (1.0.4)
     jquery-rails (2.2.0)
       railties (>= 3.0, < 5.0)
@@ -146,7 +146,7 @@ GEM
     kgio (2.8.0)
     listen (0.7.2)
     lumberjack (1.0.2)
-    mail (2.4.4)
+    mail (2.5.3)
       i18n (>= 0.4.0)
       mime-types (~> 1.16)
       treetop (~> 1.4.8)
@@ -155,7 +155,7 @@ GEM
     mime-types (1.21)
     mocha (0.10.5)
       metaclass (~> 0.0.1)
-    multi_json (1.6.1)
+    multi_json (1.7.1)
     mysql2 (0.3.11)
     nested_form (0.3.1)
     net-scp (1.0.4)
@@ -180,14 +180,14 @@ GEM
       rack
     rack-test (0.6.2)
       rack (>= 1.0)
-    rails (3.2.12)
-      actionmailer (= 3.2.12)
-      actionpack (= 3.2.12)
-      activerecord (= 3.2.12)
-      activeresource (= 3.2.12)
-      activesupport (= 3.2.12)
+    rails (3.2.13)
+      actionmailer (= 3.2.13)
+      actionpack (= 3.2.13)
+      activerecord (= 3.2.13)
+      activeresource (= 3.2.13)
+      activesupport (= 3.2.13)
       bundler (~> 1.0)
-      railties (= 3.2.12)
+      railties (= 3.2.13)
     rails_admin (0.4.3)
       bootstrap-sass (~> 2.2)
       builder (~> 3.0)
@@ -202,9 +202,9 @@ GEM
       rails (~> 3.1)
       remotipart (~> 1.0)
       sass-rails (~> 3.1)
-    railties (3.2.12)
-      actionpack (= 3.2.12)
-      activesupport (= 3.2.12)
+    railties (3.2.13)
+      actionpack (= 3.2.13)
+      activesupport (= 3.2.13)
       rack-ssl (~> 1.3.2)
       rake (>= 0.8.7)
       rdoc (~> 3.4)
@@ -212,7 +212,7 @@ GEM
     raindrops (0.10.0)
     rake (10.0.3)
     rb-fsevent (0.9.1)
-    rdoc (3.12.1)
+    rdoc (3.12.2)
       json (~> 1.4)
     remotipart (1.0.2)
     rest-client (1.6.7)
@@ -266,7 +266,7 @@ GEM
       eventmachine (>= 0.12.6)
       rack (>= 1.0.0)
     thor (0.17.0)
-    tilt (1.3.4)
+    tilt (1.3.6)
     tire (0.5.4)
       activemodel (>= 3.0)
       hashr (~> 0.0.19)
@@ -280,7 +280,7 @@ GEM
       actionpack (>= 3.1)
       execjs
       railties (>= 3.1)
-    tzinfo (0.3.35)
+    tzinfo (0.3.37)
     uglifier (1.3.0)
       execjs (>= 0.3.0)
       multi_json (~> 1.0, >= 1.0.2)
@@ -325,7 +325,7 @@ DEPENDENCIES
   nested_form
   newrelic_rpm (~> 3.5.5.38)
   pry
-  rails (= 3.2.12)
+  rails (= 3.2.13)
   rails_admin
   rb-fsevent (= 0.9.1)
   rmagick

除此之外，这两个文件没有任何变化。

来自阅读Diagnosing the cause of slow view rendering我知道 Assets 管道中的东西可能会减慢它的速度，但是当我在 development.rb 中更改“config.assets.debug = false”的值时，我看不出有什么不同。

我想我的 Assets 管道中确实有很多 Assets 我仍然需要清理，我会在部署到生产环境之前清理它，但我想知道为什么这现在突然导致更新 Rails 后出现延迟。问题是:是什么原因造成的，我可以做些什么吗？

如果您需要更多信息，请告诉我。非常感谢任何帮助。

编辑:我还在 github.com/rails/rails 上创建了一个问题，它似乎被视为回归:https://github.com/rails/rails/issues/9803 .

最佳答案

我们在 Discourse 上遇到了同样的问题.我将相关的安全修复程序提取到一个你可以应用的猴子补丁中 到 Rails 3.2 应用程序:

module HTML
  class WhiteListSanitizer
      # Sanitizes a block of css code. Used by #sanitize when it comes across a style attribute
    def sanitize_css(style)
      # disallow urls
      style = style.to_s.gsub(/url\s*\(\s*[^\s)]+?\s*\)\s*/, ' ')

      # gauntlet
      if style !~ /\A([:,;#%.\sa-zA-Z0-9!]|\w-\w|\'[\s\w]+\'|\"[\s\w]+\"|\([\d,\s]+\))*\z/ ||
          style !~ /\A(\s*[-\w]+\s*:\s*[^:;]*(;|$)\s*)*\z/
        return ''
      end

      clean = []
      style.scan(/([-\w]+)\s*:\s*([^:;]*)/) do |prop,val|
        if allowed_css_properties.include?(prop.downcase)
          clean <<  prop + ': ' + val + ';'
        elsif shorthand_css_properties.include?(prop.split('-')[0].downcase)
          unless val.split().any? do |keyword|
            !allowed_css_keywords.include?(keyword) &&
              keyword !~ /\A(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|\d{0,2}\.?\d{0,2}(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)\z/
          end
            clean << prop + ': ' + val + ';'
          end
        end
      end
      clean.join(' ')
    end
  end
end

module HTML
  class WhiteListSanitizer
    self.protocol_separator = /:|(&#0*58)|(&#x70)|(&#x0*3a)|(%|&#37;)3A/i

    def contains_bad_protocols?(attr_name, value)
      uri_attributes.include?(attr_name) &&
      (value =~ /(^[^\/:]*):|(&#0*58)|(&#x70)|(&#x0*3a)|(%|&#37;)3A/i && !allowed_protocols.include?(value.split(protocol_separator).first.downcase.strip))
    end
  end
end

module ActiveRecord
  class Relation

    def where_values_hash
      equalities = with_default_scope.where_values.grep(Arel::Nodes::Equality).find_all { |node|
        node.left.relation.name == table_name
      }

      Hash[equalities.map { |where| [where.left.name, where.right] }].with_indifferent_access
    end

  end
end

module ActiveRecord
  class PredicateBuilder # :nodoc:
    def self.build_from_hash(engine, attributes, default_table, allow_table_name = true)
      predicates = attributes.map do |column, value|
        table = default_table

        if allow_table_name && value.is_a?(Hash)
          table = Arel::Table.new(column, engine)

          if value.empty?
            '1 = 2'
          else
            build_from_hash(engine, value, table, false)
          end
        else
          column = column.to_s

          if allow_table_name && column.include?('.')
            table_name, column = column.split('.', 2)
            table = Arel::Table.new(table_name, engine)
          end

          attribute = table[column]

          case value
          when ActiveRecord::Relation
            value = value.select(value.klass.arel_table[value.klass.primary_key]) if value.select_values.empty?
            attribute.in(value.arel.ast)
          when Array, ActiveRecord::Associations::CollectionProxy
            values = value.to_a.map {|x| x.is_a?(ActiveRecord::Base) ? x.id : x}
            ranges, values = values.partition {|v| v.is_a?(Range) || v.is_a?(Arel::Relation)}

            array_predicates = ranges.map {|range| attribute.in(range)}

            if values.include?(nil)
              values = values.compact
              if values.empty?
                array_predicates << attribute.eq(nil)
              else
                array_predicates << attribute.in(values.compact).or(attribute.eq(nil))
              end
            else
              array_predicates << attribute.in(values)
            end

            array_predicates.inject {|composite, predicate| composite.or(predicate)}
          when Range, Arel::Relation
            attribute.in(value)
          when ActiveRecord::Base
            attribute.eq(value.id)
          when Class
            # FIXME: I think we need to deprecate this behavior
            attribute.eq(value.name)
          when Integer, ActiveSupport::Duration
            # Arel treats integers as literals, but they should be quoted when compared with strings
            column = engine.connection.schema_cache.columns_hash[table.name][attribute.name.to_s]
            attribute.eq(Arel::Nodes::SqlLiteral.new(engine.connection.quote(value, column)))
          else
            attribute.eq(value)
          end
        end
      end

      predicates.flatten
    end
  end
end

应用安全补丁并恢复 Rails 3.2.13 后，性能恢复正常。我们也是 在预编译我们的 Assets 时遇到 UTF-8 错误，这种情况不再发生。似乎有一个 3.2.13 补丁中的一堆非安全相关的东西破坏了东西:(

关于ruby-on-rails - 从 rails 3.2.12 更改为 3.2.13 时，是什么导致极度缓慢，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15501354/