如何在启动rails app时解决内存膨胀问题？
我在运行ruby 2.3.3和Rails 4.1.13的Heroku上使用Rails应用程序时出现内存问题。 当我在Heroku上加载应用程序时，它的启动速度约为430 Mb，但在那里相当稳定 – 但仍然在Heroku上达到512 Mb（正如预期的那样）。 我的主要问题是：如何在我的应用程序的BOOT期间精确定位并减少内存使用量？ 即我如何减少启动时使用的内存量？
我已经研究了大多数gem，例如出轨，oink，内存分析器和stackprof但是最有帮助的是Heroku上的Scout附加组件，用于查找内存膨胀和内存饥饿控制器等。通过这个我已经设法减少应用程序在内存方面增长的数量，但减少启动时使用的内存量。
我知道gem是在启动时加载的，gem越多，越大，启动时使用的内存就越多。 运行bundle exec derailed bundle:mem给我这个：
TOP: 92.3008 MiB carrierwave-aws: 16.7461 MiB carrierwave/storage/aws: 16.6094 MiB aws-sdk-core/s3: 7.9414 MiB aws-sdk-resources: 2.5703 MiB aws-sdk-core: 2.5117 MiB jmespath: 1.8867 MiB jmespath/nodes: 1.1406 MiB jmespath/nodes/function: 0.3867 MiB seahorse/client/base: 0.9414 MiB seahorse/client/plugins/net_http: 0.5273 MiB aws-sdk-core/xml/parser/engines/rexml: 0.8633 MiB rexml/document: 0.8516 MiB rexml/element: 0.5508 MiB rails/all: 13.6992 MiB rails: 8.9453 MiB (Also required by: active_record/railtie, active_model/railtie, and 6 others) rails/application: 7.2188 MiB rails/engine: 6.8672 MiB (Also required by: coffee/rails/engine) rails/railtie: 6.5898 MiB (Also required by: sprockets/railtie, jbuilder/railtie) rails/configuration: 6.3398 MiB (Also required by: rails/railtie/configuration) active_support/core_ext/object: 6.0586 MiB active_support/core_ext/object/conversions: 4.7227 MiB active_support/core_ext/hash/conversions: 4.0039 MiB (Also required by: active_support/core_ext/hash, active_record/serializers/xml_serializer) active_support/time: 3.8008 MiB (Also required by: active_record/base) active_support/core_ext/time: 3.0938 MiB active_support/core_ext/time/calculations: 2.9922 MiB (Also required by: active_support/core_ext/numeric/time, active_support/core_ext/string/conversions) active_support/core_ext/time/conversions: 2.2148 MiB (Also required by: active_support/core_ext/time, active_support/core_ext/date_time/conversions) active_support/values/time_zone: 2.1602 MiB (Also required by: active_support/time_with_zone, active_support/core_ext/date_time/conversions) tzinfo: 1.8984 MiB active_support/core_ext/array/conversions: 0.6211 MiB (Also required by: active_support/duration, action_dispatch/http/request, and 2 others) active_support/xml_mini: 0.5508 MiB (Also required by: active_support/core_ext/hash/conversions) active_support/core_ext/object/json: 1.0352 MiB (Also required by: active_support/json/encoding) json: 0.7227 MiB (Also required by: active_support/json/decoding, pg/text_encoder, and 19 others) json/common: 0.3906 MiB (Also required by: json/ext) active_support: 0.7109 MiB (Also required by: active_support/time, active_support/railtie, and 5 others) active_support/dependencies/autoload: 0.332 MiB (Also required by: rails, active_support/rails) active_support/inflector/methods: 0.332 MiB (Also required by: active_support/core_ext/string/inflections, active_support/core_ext/time/conversions, and 5 others) active_support/inflections: 0.3164 MiB (Also required by: active_support/inflector) active_support/logger: 0.3281 MiB action_dispatch/railtie: 0.668 MiB (Also required by: action_controller/railtie) action_dispatch: 0.6289 MiB (Also required by: action_controller) active_support/rails: 0.4414 MiB (Also required by: active_record, active_model, and 4 others) active_support/deprecation: 0.418 MiB (Also required by: sass/rails/helpers, formtastic/deprecation) active_record/railtie: 2.8555 MiB active_record: 1.9766 MiB (Also required by: friendly_id) active_record/connection_adapters/abstract_adapter: 0.8516 MiB arel: 0.8086 MiB (Also required by: active_record/base) arel/visitors: 0.3438 MiB action_controller/railtie: 0.875 MiB (Also required by: rails/all, sprockets/railtie) action_controller: 0.6797 MiB (Also required by: heroku_rails_deflate/serve_zipped_assets) action_controller/metal/live: 0.332 MiB sprockets/railtie: 1.8516 MiB (Also required by: sass/rails/railtie) sprockets/rails/helper: 0.918 MiB action_view/helpers: 0.8945 MiB (Also required by: action_view/base) action_view/helpers/form_helper: 0.3828 MiB (Also required by: action_view/helpers/form_options_helper) sprockets: 0.9102 MiB (Also required by: sprockets/rails/helper) sprockets/directive_processor: 0.5586 MiB yaml: 0.5078 MiB (Also required by: active_support/ordered_hash, hirb, and 7 others) psych: 0.5078 MiB rails3-jquery-autocomplete: 9.9102 MiB action_controller/base: 8.4922 MiB action_controller/metal: 1.8281 MiB abstract_controller/base: 1.0898 MiB erubis: 0.8477 MiB (Also required by: action_view/template/handlers/erb, heroics) erubis/engine: 0.4063 MiB (Also required by: erubis/engine/eruby) action_dispatch/middleware/stack: 0.6367 MiB active_support/dependencies: 0.5703 MiB (Also required by: abstract_controller/helpers, active_record/base) abstract_controller/rendering: 1.5625 MiB action_view/view_paths: 1.4531 MiB (Also required by: action_view/rendering) action_view/base: 1.3477 MiB action_view/lookup_context: 0.5156 MiB action_view/template: 0.3789 MiB (Also required by: action_view/template/resolver) action_controller/metal/redirecting: 1.0586 MiB action_controller/metal/rack_delegation: 0.9297 MiB action_dispatch/http/request: 0.8555 MiB action_controller/metal/request_forgery_protection: 0.5859 MiB action_controller/metal/params_wrapper: 0.5 MiB action_dispatch/http/mime_type: 0.375 MiB (Also required by: abstract_controller/collector, jbuilder/jbuilder_template) action_controller/metal/url_for: 0.3008 MiB rails3-jquery-autocomplete/formtastic: 1.2578 MiB formtastic/inputs/base: 0.8125 MiB fog: 8.6523 MiB fog/vcloud_director: 1.0156 MiB fog/vcloud_director/compute: 0.9961 MiB fog/vcloud_director/query: 0.4453 MiB pp: 0.418 MiB (Also required by: scout_apm) fog/openstack: 0.8398 MiB fog/cloudstack: 0.5859 MiB fog/cloudstack/compute: 0.5859 MiB fog/internet_archive: 0.543 MiB fog/internet_archive/storage: 0.5352 MiB fog/internet_archive/core: 0.3125 MiB fog/rackspace: 0.3867 MiB fog/cloudsigma: 0.3594 MiB fog/cloudsigma/compute: 0.3047 MiB fog/vcloud: 0.3203 MiB fog/vcloud/compute: 0.3125 MiB fog/aws: 0.3125 MiB twitter: 8.3711 MiB addressable/uri: 4.2422 MiB (Also required by: twitter/base, twitter/rest/request, and 8 others) addressable/idna: 2.7891 MiB addressable/idna/pure: 2.7461 MiB public_suffix: 0.3242 MiB twitter/streaming/client: 1.7266 MiB twitter/streaming/response: 1.4453 MiB http: 1.418 MiB http/response: 1.2109 MiB http/cookie_jar: 0.9219 MiB http/cookie: 0.9102 MiB domain_name: 0.8203 MiB domain_name/etld_data: 0.7813 MiB twitter/configuration: 0.8477 MiB (Also required by: twitter/rest/help) twitter/base: 0.6016 MiB (Also required by: twitter/entity, twitter/identity, and 12 others) twitter/null_object: 0.4688 MiB (Also required by: twitter/trend_results) naught: 0.4063 MiB twitter/cursor: 0.8164 MiB (Also required by: twitter/rest/utils, twitter/rest/friends_and_followers, and 2 others) twitter/rest/request: 0.7852 MiB (Also required by: twitter/rest/utils, twitter/rest/friends_and_followers, and 8 others) faraday: 0.6406 MiB (Also required by: twitter/rest/client, twitter/rest/response/parse_json, and 6 others) twitter/rest/client: 0.418 MiB twitter/rest/api: 0.3828 MiB asset_sync: 4.9609 MiB asset_sync/multi_mime: 4.5039 MiB mime/types: 4.4883 MiB (Also required by: mime/types/columnar) mime/types/registry: 4.1914 MiB asset_sync/storage: 0.4375 MiB fog/core: 0.4063 MiB (Also required by: fog, fog/xml, and 48 others) platform-api: 4.5273 MiB platform-api/client: 2.8359 MiB newrelic_rpm: 3.875 MiB new_relic/control: 3.875 MiB new_relic/agent: 3.4883 MiB new_relic/agent/agent: 1.7422 MiB new_relic/agent/configuration/manager: 0.4961 MiB (Also required by: new_relic/agent/configuration) new_relic/agent/configuration/default_source: 0.3633 MiB new_relic/agent/transaction_sampler: 0.3516 MiB carrierwave: 2.8281 MiB (Also required by: carrierwave-aws) carrierwave/uploader: 1.7656 MiB friendly_id: 2.5273 MiB friendly_id/object_utils: 2.4453 MiB active_record/base: 2.4258 MiB active_record/querying: 0.3906 MiB compass: 2.1328 MiB (Also required by: compass-rails) compass/sass_extensions: 1.2461 MiB compass/sass_extensions/sprites: 0.6875 MiB compass/sass_extensions/sprites/engines: 0.4609 MiB compass/sass_extensions/sprites/engines/chunky_png_engine: 0.4492 MiB chunky_png: 0.4492 MiB compass/sass_extensions/functions: 0.5078 MiB compass/configuration: 0.6172 MiB compass/configuration/data: 0.6133 MiB pg: 2.1055 MiB pg_ext: 1.9102 MiB feedjira: 2.0781 MiB loofah: 0.625 MiB sax-machine: 0.4414 MiB sass-rails: 1.8047 MiB sass/rails: 1.8008 MiB sass/rails/helpers: 1.7578 MiB sprockets/sass_functions: 1.7383 MiB sass: 1.7383 MiB (Also required by: sass/rails/importer, sprockets/sass_importer) sass/engine: 1.4492 MiB sass/script: 0.5586 MiB (Also required by: sass/script/css_parser) sass/scss: 0.3281 MiB sass/scss/parser: 0.3047 MiB scout_apm: 1.418 MiB webrick: 0.5664 MiB jbuilder: 1.1016 MiB (Also required by: jbuilder/jbuilder_template) active_support/cache: 0.3906 MiB rmagick: 1.0234 MiB rmagick_internal.rb: 1.0195 MiB RMagick2.so: 0.6875 MiB lazyload-rails: 0.8555 MiB nokogiri: 0.8555 MiB (Also required by: TOP, sax-machine/handlers/sax_nokogiri_handler, and 5 others) sitemap_generator: 0.5195 MiB dalli: 0.4648 MiB unicorn: 0.457 MiB hirb: 0.3984 MiB
我想92Mb在gem方面相当多，但我确实在应用程序中使用它们。 Carrierwave是最大的，但在我如何在AWS（以及Fog）上缓存图像等方面非常重要。 这仅占启动时使用的内存的大约1/4。
在我的应用程序控制器中，我有一个前置filter，我在其中加载一些在整个网站中使用的变量（在全局标题，侧边栏等中），如下所示：
@search = TextSearch.new @administrator_logged_in = current_administrator @nbr_of_stores_total = Store.active.size # Used in header @nbr_of_blog_posts_total = BlogPost.once_posted.size # Used in header contests_open = Contest.active.open.size @active_contests_string = contests_open > 0 ? " (" << contests_open.to_s << ")" : "" add_breadcrumb "Home", root_path @open_graph_image = "https://s3.eu-central-1.amazonaws.com/myapp/assets/myapp_logo_large.png" # Season-related @is_christmas = false @gift_word_seasonal = "christmas presents"
我想这会加载到启动（和整体）内存中，对吧？
我应该在哪里寻找启动内存使用？ 简而言之：
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我的rails应用程序应该在启动内存（如中间件，初始化程序等）时遇到问题？
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我可以使用哪些工具（例如上面的出轨命令）查找/查明内存饥饿的呼叫/操作？
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我无法找到解决问题的直接因果关系。 比如，找到答案“如果我删除此代码，我会节省多少内存？”。 我应该如何衡量/基准测试我在我的应用上执行的任何操作（而不是上传并检查图表中的整体用法）？
尝试运行GC.stat命令这将根据您可以决定的内容提供有关内存使用情况和垃圾收集的信息。
内存分析https://github.com/ice799/memprof也可能对您有所帮助