ruby-on-rails - Rails 加载页面的时间比预期的要长

Question

我在 Rails 控制台中看到了这些统计数据

在 879 毫秒内完成 200 OK( View :57.5 毫秒 | ActiveRecord:3.2 毫秒)

如您所见， View 加载时间和事件记录时间大约需要 60 毫秒。但相反，加载时间为 879 毫秒。其他800ms可以归于哪里？ (有时长达 2000 毫秒)

全程追踪

Started GET "/index" for 127.0.0.1 at 2017-03-17 02:10:13 +0200
Processing by HomeController#index as HTML
  User Load (0.2ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1  ORDER BY "users"."id" ASC LIMIT 1  [["id", 2]]
  User Exists (0.6ms)  SELECT  1 AS one FROM "users" WHERE ("users"."firstname" = 'Andr' AND "users"."id" != 2 AND "users"."is_artist" = 't') LIMIT 1
  User Exists (0.4ms)  SELECT  1 AS one FROM "users" WHERE ("users"."cname" = 'chic' AND "users"."id" != 2 AND "users"."is_artist" = 't') LIMIT 1
  User Exists (0.4ms)  SELECT  1 AS one FROM "users" WHERE ("users"."email" = 'pk00218@surrey.ac.uk' AND "users"."id" != 2 AND "users"."is_artist" = 't') LIMIT 1
  User Exists (0.4ms)  SELECT  1 AS one FROM "users" WHERE ("users"."spotify_name" = 'nickelback' AND "users"."id" != 2 AND "users"."is_artist" = 't') LIMIT 1
  User Exists (0.2ms)  SELECT  1 AS one FROM "users" WHERE ("users"."soundcloud_link" = 'nickelback' AND "users"."id" != 2 AND "users"."is_artist" = 't') LIMIT 1
  Rendered layouts/_search_bar.html.erb (0.3ms)
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE "users"."is_artist" = $1  [["is_artist", "t"]]
  Tagging Load (0.4ms)  SELECT "taggings".* FROM "taggings" WHERE "taggings"."user_id" IN (1, 2)
  Tag Load (0.3ms)  SELECT "tags".* FROM "tags" WHERE "tags"."id" IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
  Rendered shared/_artist_tile.html.erb (3.4ms)
  Rendered shared/_artist_tile.html.erb (1.6ms)
  Rendered shared/_artist_tile.html.erb (1.6ms)
  Rendered home/index.html.erb within layouts/application (17.6ms)
   (0.2ms)  SELECT COUNT(*) FROM "collective_requests" WHERE "collective_requests"."receiver_id" = $1 AND "collective_requests"."accepted" IS NULL  [["receiver_id", 2]]
  CACHE (0.0ms)  SELECT COUNT(*) FROM "collective_requests" WHERE "collective_requests"."receiver_id" = $1 AND "collective_requests"."accepted" IS NULL  [["receiver_id", 2]]
  Rendered layouts/_navlinks.html.erb (3.1ms)
  Rendered layouts/_header.html.erb (4.8ms)
  Rendered layouts/_footer.html.erb (1.1ms)
Completed 200 OK in 879ms (Views: 57.5ms | ActiveRecord: 3.2ms)

Rails 版本是 4.2.6

Answer 1

Rails 无法衡量您的代码所做的一切(例如，连接到 Redis、方法中的复杂逻辑)。您需要像 New Relic 这样的 APM 工具来找出您的代码的哪一部分是缓慢的。

这是每种方法和所用时间的示例跟踪:

引用 - https://blog.newrelic.com/2012/06/21/adventures-in-performance-tuning/