If you are new to either please see the Getting Started with Rails 4.x on Heroku instead.
Rails logs one entry when a request is received and another when it completes.
If you want to know the current log level, you can call the Processing Articles Controller#create (for 127.0.0.1 at 2008-09-08 ) [POST] Session ID: BAh7Bzo MY3Ny Zl9p ZCIl MDY5MWU1M2I1ZDRj ODBl Mzky MWI1OTg2NWQy Nz Vi Zj Yi Cm Zs YXNo SUM6J0Fjd Gl vbk Nvbn Ryb2xs ZXI6Ok Zs YXNo Ojp Gb GFza Ehhc2h7AAY6Ck B1c2Vkew A=--b18cd92fba90eacf8137e5f6b3b06c4d724596a4 Parameters: New article: Article should be valid: true Article Create (0.000443) INSERT INTO "articles" ("updated_at", "title", "body", "published", "created_at") VALUES('2008-09-08 ', 'Debugging Rails', 'I''m learning how to print in logs!!!
', 'f', '2008-09-08 ') The article was saved and now the user is going to be redirected...
ruby/object Article attributes: updated_at: 2008-09-05 body: It's a very helpful guide for debugging your Rails app.
title: Rails debugging guide published: t id: "1" created_at: 2008-09-05 attributes_cache: Title: Rails debugging guide When something is logged, it's printed into the corresponding log if the log level of the message is equal to or higher than the configured log level.