stackprof VS rack-mini-profiler

stackprof can be used alone/by itself to generate flamegraphs for arbitrary Ruby code.

I’d use something like stackprof ( https://github.com/tmm1/stackprof ) to see where the time is going. If you already have suspicions you can use it to get information about a specific method / few lines of Ruby but there’s also a rack middleware.

stackprof

Other profilers, such as stackprof, trace everything that’s happening by line. These types of profilers usually need some instrumentation to be configured, as shown below:

Either https://github.com/tmm1/stackprof for cpu or https://github.com/SamSaffron/memory_profiler for memory. In practice profiling and removing allocations also gives a large perf boost.

At first, I tried to benchmark the method using the benchmark library. (The profiler uses stackprof)

Author of peek here. Honestly, I got burnt out. We stopped using this internally at GitHub which made it difficult to continue working on. Rails was going through its identity crisis with asset pipelines.

https://github.com/MiniProfiler/rack-mini-profiler gets you most of the way there and comes by default in the Gemfile for new Rails applications.

This already exists to some degree: https://github.com/MiniProfiler/rack-mini-profiler

rack-mini-profiler will generate flamegraphs for Rails backend requests.

Have you tried using https://github.com/MiniProfiler/rack-mini-profiler to get a clear breakdown of where your server is spending it's time filling the requests? If rack-mini-profiler is too much for you to deal with right now, you can still get a good idea just using the https://github.com/ruby/benchmark gem and wrapping some of your requests in a benchmark.

# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main" gem "rails", "~> 7.0.4" # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails] gem "sprockets-rails" # Use sqlite3 as the database for Active Record gem "sqlite3", "~> 1.4" # Use the Puma web server [https://github.com/puma/puma] gem "puma", "~> 5.0" # Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails] gem "importmap-rails" # Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev] gem "turbo-rails" # Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev] gem "stimulus-rails" # Build JSON APIs with ease [https://github.com/rails/jbuilder] gem "jbuilder" # Windows does not include zoneinfo files, so bundle the tzinfo-data gem gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ] # Reduces boot times through caching; required in config/boot.rb gem "bootsnap", require: false # Use Sass to process CSS # gem "sassc-rails" # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images] # gem "image_processing", "~> 1.2" group :development, :test do # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem gem "debug", platforms: %i[ mri mingw x64_mingw ] end group :development do # Use console on exceptions pages [https://github.com/rails/web-console] gem "web-console" # Add speed badges [https://github.com/MiniProfiler/rack-mini-profiler] # gem "rack-mini-profiler" # Speed up commands on slow machines / big apps [https://github.com/rails/spring] # gem "spring" end group :test do # Use system testing [https://guides.rubyonrails.org/testing.html#system-testing] gem "capybara" gem "selenium-webdriver" gem "webdrivers" end

rack-mini-profiler

For a quick ad hoc peek at the performance of pages that you can request yourself, without having to go through the hoops of connecting to and committing to an external service, this gem can also be useful: https://github.com/MiniProfiler/rack-mini-profiler