RssObserver
Rails middleware for observing of RSS memory changes around the request. Under the hood, it utilizes the get_process_mem gem.
Installation
Add the line
gem 'rss_observer'
to your Gemfile and run bundle install.
Configuration
To use this middleware in a Rails application, modify relevant environment file (or application.rb to log rss in all environments).
You can use the supplied STDOUT logger and insert the RssObserver middleware after Rails::Rack::Logger.
require 'rss_observer/logger_handler'
module FooApp
class Application < Rails::Application
# ...
config.middleware.insert_after Rails::Rack::Logger, RssObserver::Middleware, RssObserver::LoggerHandler.new
end
endMore realistically, you'll need something more production-ready.
You can prepare a custom class that will make use of Rails.logger, that, with request_id in log tags will allow you to match
the usage log with actual request logs.
# lib/rails_logger_handler.rb
class RailsLoggerHandler
def initial_memory(kilobytes)
Thread.current[:_initial_memory] = kilobytes
end
def final_memory(kilobytes)
Rails.logger.info "Memory change: #{final_memory - Thread.current[:_initial_memory]} KB"
end
end
# config/application.rb
require_relative '../lib/rails_logger_handler'
module FooApp
class Application < Rails::Application
# ...
config.log_tags = [:request_id]
config.middleware.insert_after Rails::Rack::Logger, RssObserver::Middleware, RailsLoggerHandler.new
end
endExample
RssObserver vs Default Rails request logs
I, [2019-09-03T14:56:22.735264 #7290] INFO -- : [96956f1a-7f7f-4836-a8a1-bc3c05696433] Completed 200 OK in 47ms (Views: 29.7ms | ActiveRecord: 6.3ms | Allocations: 18614)
I, [2019-09-03T14:56:22.737113 #7290] INFO -- : [96956f1a-7f7f-4836-a8a1-bc3c05696433] Memory change: 264.0 KB