我的Rails应用程序中的Postgres性能问题
[英]Postgres performance issue in my Rails app
问题描述
我正在使用derailed_benchmark gem来跟踪我的应用程序性能：
$ PATH_TO_HIT="/api/v2/feed.json?per_page=30&page=1&category_name=Feed" USER_SERVER=webrick TEST_COUNT=20 bundle exec derailed exec perf:stackprof
==================================
Mode: cpu(1000)
Samples: 20708 (0.42% miss rate)
GC: 3219 (15.54%)
==================================
TOTAL (pct) SAMPLES (pct) FRAME
4720 (22.8%) 4694 (22.7%) block in ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#exec_cache
542 (2.6%) 502 (2.4%) ActiveSupport::Inflector#underscore
413 (2.0%) 413 (2.0%) ActiveSupport::PerThreadRegistry#instance
364 (1.8%) 364 (1.8%) ActiveRecord::QueryMethods#validate_order_args
309 (1.5%) 309 (1.5%) block in ActiveSupport::Inflector#apply_inflections
282 (1.4%) 282 (1.4%) ThreadSafe::NonConcurrentCacheBackend#[]
257 (1.2%) 257 (1.2%) ActiveRecord::Relation#initialize
410 (2.0%) 235 (1.1%) ActiveRecord::Relation#initialize_copy
229 (1.1%) 229 (1.1%) ActiveRecord::Delegation::DelegateCache#relation_delegate_class
212 (1.0%) 212 (1.0%) block in ActiveRecord::Relation::Merger#merge
562 (2.7%) 198 (1.0%) ActiveRecord::QueryMethods#preprocess_order_args
190 (0.9%) 189 (0.9%) ActiveRecord::Core::ClassMethods#arel_table
181 (0.9%) 181 (0.9%) JSON#parse
175 (0.8%) 175 (0.8%) ActiveRecord::Relation#reset
165 (0.8%) 165 (0.8%) ActiveRecord::Attribute#initialize
153 (0.7%) 153 (0.7%) ActiveRecord::Relation#values
151 (0.7%) 151 (0.7%) ActiveRecord::Inheritance::ClassMethods#base_class
333 (1.6%) 151 (0.7%) ActiveRecord::Scoping::Default::ClassMethods#build_default_scope
144 (0.7%) 144 (0.7%) Skylight::Normalizers::ActiveRecord::SQL#extract_rust
142 (0.7%) 142 (0.7%) ActiveRecord::QueryMethods#joins_values
138 (0.7%) 138 (0.7%) block (4 levels) in Class#class_attribute
195 (0.9%) 133 (0.6%) ActiveRecord::DynamicMatchers#respond_to?
158 (0.8%) 121 (0.6%) ActiveRecord::QueryMethods#where_values=
125 (0.6%) 115 (0.6%) ActiveRecord::Reflection::AssociationReflection#klass
113 (0.5%) 113 (0.5%) ActiveRecord::Result#initialize_copy
110 (0.5%) 110 (0.5%) Arel::Table#initialize
193 (0.9%) 109 (0.5%) ActiveRecord::ConnectionAdapters::PostgreSQL::Utils#extract_schema_qualified_name
114 (0.6%) 106 (0.5%) Arel::Nodes::Binary#hash
104 (0.5%) 104 (0.5%) ActiveRecord::QueryMethods#extending_values
99 (0.5%) 99 (0.5%) ActiveRecord::QueryMethods#order_values
如何修复“ActiveRecord :: ConnectionAdapters :: PostgreSQLAdapter＃exec_cache中的块”性能问题？
UPDATE
在我的config / application.rb中使用“config.middleware.delete”ActiveRecord :: QueryCache“运行相同的命令后，结果如下：
==================================
Mode: cpu(1000)
Samples: 21116 (0.42% miss rate)
GC: 2213 (10.48%)
==================================
TOTAL (pct) SAMPLES (pct) FRAME
5619 (26.6%) 5600 (26.5%) block in ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#exec_cache
2268 (10.7%) 2268 (10.7%) block in ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#exec_no_cache
421 (2.0%) 383 (1.8%) ActiveSupport::Inflector#underscore
304 (1.4%) 304 (1.4%) ActiveSupport::PerThreadRegistry#instance
294 (1.4%) 294 (1.4%) block in ActiveSupport::Inflector#apply_inflections
270 (1.3%) 270 (1.3%) ThreadSafe::NonConcurrentCacheBackend#[]
245 (1.2%) 245 (1.2%) ActiveRecord::Relation#initialize
229 (1.1%) 229 (1.1%) ActiveRecord::QueryMethods#validate_order_args
219 (1.0%) 219 (1.0%) ActiveRecord::Delegation::DelegateCache#relation_delegate_class
207 (1.0%) 207 (1.0%) ActiveRecord::Inheritance::ClassMethods#base_class
285 (1.3%) 188 (0.9%) ActiveRecord::Relation#initialize_copy
184 (0.9%) 184 (0.9%) ActiveRecord::Attribute#initialize
181 (0.9%) 179 (0.8%) ActiveRecord::Core::ClassMethods#arel_table
175 (0.8%) 175 (0.8%) Skylight::Normalizers::ActiveRecord::SQL#extract_rust
165 (0.8%) 165 (0.8%) block in ActiveRecord::Relation::Merger#merge
147 (0.7%) 147 (0.7%) block (4 levels) in Class#class_attribute
374 (1.8%) 145 (0.7%) ActiveRecord::QueryMethods#preprocess_order_args
113 (0.5%) 113 (0.5%) ActiveRecord::Relation#values
112 (0.5%) 112 (0.5%) ActiveRecord::QueryMethods#joins_values
171 (0.8%) 109 (0.5%) ActiveRecord::ConnectionAdapters::PostgreSQL::Utils#extract_schema_qualified_name
99 (0.5%) 99 (0.5%) Arel::Table#initialize
97 (0.5%) 97 (0.5%) ActiveRecord::Relation#reset
271 (1.3%) 96 (0.5%) ActiveRecord::Scoping::Default::ClassMethods#build_default_scope
107 (0.5%) 95 (0.4%) ActiveRecord::Reflection::AssociationReflection#klass
93 (0.4%) 93 (0.4%) ActiveRecord::QueryMethods#order_values
125 (0.6%) 93 (0.4%) ActiveRecord::QueryMethods#where_values=
88 (0.4%) 88 (0.4%) ActiveRecord::Reflection::ThroughReflection#active_record
106 (0.5%) 87 (0.4%) Skylight::Trace#start
81 (0.4%) 81 (0.4%) ActiveRecord::QueryMethods#check_cached_relation
80 (0.4%) 80 (0.4%) ActiveRecord::QueryMethods#where_values
UDPATE 2
使用“wall time”模式而不是“cpu time”模式运行查询后，结果如下：
==================================
Mode: wall(1000)
Samples: 41424 (1.92% miss rate)
GC: 3648 (8.81%)
==================================
TOTAL (pct) SAMPLES (pct) FRAME
4780 (11.5%) 4718 (11.4%) block in ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#exec_cache
2783 (6.7%) 2783 (6.7%) block in ActiveRecord::ConnectionAdapters::PostgreSQLAdapter#exec_no_cache
1088 (2.6%) 1088 (2.6%) ActiveSupport::PerThreadRegistry#instance
934 (2.3%) 934 (2.3%) ThreadSafe::NonConcurrentCacheBackend#[]
1031 (2.5%) 926 (2.2%) ActiveSupport::Inflector#underscore
739 (1.8%) 739 (1.8%) block in ActiveSupport::Inflector#apply_inflections
626 (1.5%) 626 (1.5%) ActiveRecord::Relation#initialize
589 (1.4%) 589 (1.4%) ActiveRecord::Delegation::DelegateCache#relation_delegate_class
577 (1.4%) 577 (1.4%) ThreadSafe::NonConcurrentCacheBackend#get_or_default
549 (1.3%) 549 (1.3%) ActiveRecord::Attribute#initialize
497 (1.2%) 497 (1.2%) block in ActiveRecord::Relation::Merger#merge
497 (1.2%) 497 (1.2%) ActiveRecord::QueryMethods#validate_order_args
702 (1.7%) 424 (1.0%) ActiveRecord::Relation#initialize_copy
419 (1.0%) 417 (1.0%) ActiveRecord::Core::ClassMethods#arel_table
384 (0.9%) 384 (0.9%) ActiveRecord::Inheritance::ClassMethods#base_class
383 (0.9%) 383 (0.9%) block (4 levels) in Class#class_attribute
358 (0.9%) 358 (0.9%) Skylight::Normalizers::ActiveRecord::SQL#extract_rust
329 (0.8%) 329 (0.8%) ActiveRecord::Base.logger
321 (0.8%) 321 (0.8%) rescue in Net::BufferedIO#rbuf_fill
315 (0.8%) 315 (0.8%) ActiveRecord::Core#update_attributes_from_transaction_state
314 (0.8%) 314 (0.8%) ActiveRecord::ConnectionAdapters::AbstractAdapter#type_map
795 (1.9%) 298 (0.7%) ActiveRecord::QueryMethods#preprocess_order_args
284 (0.7%) 284 (0.7%) Arel::Table#initialize
279 (0.7%) 279 (0.7%) ActiveRecord::Relation#values
278 (0.7%) 278 (0.7%) ActiveRecord::Relation#reset
734 (1.8%) 264 (0.6%) ActiveRecord::Scoping::Default::ClassMethods#build_default_scope
263 (0.6%) 263 (0.6%) ActiveRecord::QueryMethods#joins_values
394 (1.0%) 258 (0.6%) ActiveRecord::ConnectionAdapters::PostgreSQL::Utils#extract_schema_qualified_name
15323 (37.0%) 249 (0.6%) ActiveRecord::Querying#find_by_sql
257 (0.6%) 246 (0.6%) ActiveRecord::Reflection::AssociationReflection#klass
我正在使用index.json.jbuilder构建我的feed.json，它的外观如下：
json.battles @battles do |battle|
if (battle.products.size == 2)
battle_results = battle.calculate_results
json.(battle, :id)
vote = battle.votes.find_by(user_id: current_user.id)
json.voted vote.present?
if vote
json.product_voted vote.product.id == battle.products[0].id ? "first" : "second"
end
json.mybattle battle.try(:user).try(:id) == current_user.id
json.user do
username = ""
if (battle.try(:user).try(:nickname).present?)
username = battle.try(:user).try(:nickname)
else
username = battle.try(:user).try(:name).try(:downcase).try(:delete,' ')
end
json.username username
json.user_id battle.try(:user_id)
json.profile_image battle.try(:user).try(:image) || ""
json.full_name battle.try(:user).try(:name) || ""
end
json.votes battle_results[:votes]
json.created_at time_ago_in_words(battle.created_at) + " ago"
json.title battle.title
json.first_product do
first_product = battle.products[0]
json.id first_product.id
json.voted first_product.votes.find_by(user_id: current_user.id).present?
json.percentage battle_results[:percentage_product_one]
# json.percentage_after_voting battle_results[:percentage_after_voting_product_one]
json.name first_product.name
json.price SearchFunctions.convert_currency(first_product.price.to_s, current_user.currency_code, 'USD')
# json.price first_product.price.to_s
json.url first_product.url
if first_product.images["sub"] && first_product.images["sub"].kind_of?(Array)
first_product.images["sub"] = first_product.images["sub"].first(10)
end
json.images first_product.images
json.manufacturer first_product.manufacturer
json.description first_product.description
json.is_user_saved first_product.saved_products.find_by(user_id: current_user.id).present?
json.saved_count first_product.saved_products.length
end
json.second_product do
second_product = battle.products[1]
json.id second_product.id
json.voted second_product.votes.find_by(user_id: current_user.id).present?
json.percentage battle_results[:percentage_product_two]
# json.percentage_after_voting battle_results[:percentage_after_voting_product_two]
json.name second_product.name
json.price SearchFunctions.convert_currency(second_product.price.to_s, current_user.currency_code, 'USD')
# json.price second_product.price.to_s
json.url second_product.url
if second_product.images["sub"] && second_product.images["sub"].kind_of?(Array)
second_product.images["sub"] = second_product.images["sub"].first(10)
end
json.images second_product.images
json.manufacturer second_product.manufacturer
json.description second_product.description
json.is_user_saved second_product.saved_products.find_by(user_id: current_user.id).present?
json.saved_count second_product.saved_products.length
end
end
end
1 个解决方案
解决方案1
3 2016-08-27 09:54:15
嗯，这可能是愚蠢的答案，但您可能应该减少或优化在构建feed.json期间执行的查询数量。 检查N + 1个查询，例如，您可能正在为每个Feed项目或类似内容加载作者。
您可以使用bullet gem来帮助您查找N + 1个查询。 您可以通过在查询中添加包含来解决这些问题。
更新基于json视图。
这是相当大的json，看起来你使用了很多来自你的应用程序的模型。 通过观察这一点，我们无法就如何优化这一点给出任何明确的指导。 您可能应该将整个应用程序粘贴到此处，但我认为这不适合SO。
当然，数据库方面还有很大的改进空间，但我认为最好也是最简单的方法就是缓存这个视图。 通过缓存，我的意思是为每个单独的战斗使用片段缓存。
json.battles @battles do |battle|
if (battle.products.size == 2)
json.cache! "#{battle.id}/#{battle.updated_at}" do
battle_results = battle.calculate_results
json.(battle, :id)
vote = battle.votes.find_by(user_id: current_user.id)
json.voted vote.present?
if vote
json.product_voted vote.product.id == battle.products[0].id ? "first" : "second"
end
json.mybattle battle.try(:user).try(:id) == current_user.id
json.user do
username = ""
if (battle.try(:user).try(:nickname).present?)
username = battle.try(:user).try(:nickname)
else
username = battle.try(:user).try(:name).try(:downcase).try(:delete,' ')
end
json.username username
json.user_id battle.try(:user_id)
json.profile_image battle.try(:user).try(:image) || ""
json.full_name battle.try(:user).try(:name) || ""
end
json.votes battle_results[:votes]
json.created_at time_ago_in_words(battle.created_at) + " ago"
json.title battle.title
json.first_product do
first_product = battle.products[0]
json.id first_product.id
json.voted first_product.votes.find_by(user_id: current_user.id).present?
json.percentage battle_results[:percentage_product_one]
# json.percentage_after_voting battle_results[:percentage_after_voting_product_one]
json.name first_product.name
json.price SearchFunctions.convert_currency(first_product.price.to_s, current_user.currency_code, 'USD')
# json.price first_product.price.to_s
json.url first_product.url
if first_product.images["sub"] && first_product.images["sub"].kind_of?(Array)
first_product.images["sub"] = first_product.images["sub"].first(10)
end
json.images first_product.images
json.manufacturer first_product.manufacturer
json.description first_product.description
json.is_user_saved first_product.saved_products.find_by(user_id: current_user.id).present?
json.saved_count first_product.saved_products.length
end
json.second_product do
second_product = battle.products[1]
json.id second_product.id
json.voted second_product.votes.find_by(user_id: current_user.id).present?
json.percentage battle_results[:percentage_product_two]
# json.percentage_after_voting battle_results[:percentage_after_voting_product_two]
json.name second_product.name
json.price SearchFunctions.convert_currency(second_product.price.to_s, current_user.currency_code, 'USD')
# json.price second_product.price.to_s
json.url second_product.url
if second_product.images["sub"] && second_product.images["sub"].kind_of?(Array)
second_product.images["sub"] = second_product.images["sub"].first(10)
end
json.images second_product.images
json.manufacturer second_product.manufacturer
json.description second_product.description
json.is_user_saved second_product.saved_products.find_by(user_id: current_user.id).present?
json.saved_count second_product.saved_products.length
end
end
end
end
我在第3行添加了一些代码。我刚刚写了这篇文章，我不确定语法是否100％正确，但它应该给你一个提示。 还要记住，在开发环境中未启用缓存。 要启用它，您需要在config/environments/developement.rb设置config.action_controller.perform_caching = true
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