Error 500 causes bloat / memory leak in middleware

Question

I recently discovered that I get memory bursts when I experience 500 error code in my Rails applications (I run several and experience the same thing). I found out using Scout, and every time I had a 500 error, I saw a sample of memory leaks (almost). Below is the most recent example:

Although the graph shows that exception_notification does not have a large amount of memory, but rather "Middleware". The only middleware that I use (as far as I know) is the exception notification ( gem '[exception_notification][2]'v. 4.2.1), so I assume that this should be it, and that only my interpretation is incorrect.

Edit after comment by Alexis - I ran:

Rails.configuration.middleware.each do |m|
puts "use #{m.inspect}"
end;0

:

use UTF8Cleaner::Middleware
use Rack::Sendfile
use ActionDispatch::Static
use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x0055f8e1dd5a60>
use Rack::Timeout
use Rack::Runtime
use Rack::MethodOverride
use ActionDispatch::RequestId
use Rails::Rack::Logger
use ActionDispatch::ShowExceptions
use ActionDispatch::DebugExceptions
use ActionDispatch::RemoteIp
use ActionDispatch::Callbacks
use ActiveRecord::ConnectionAdapters::ConnectionManagement
use Airbrake::Rack::Middleware
use ActiveRecord::QueryCache
use ActionDispatch::Cookies
use ActionDispatch::Session::CookieStore
use ActionDispatch::Flash
use ActionDispatch::ParamsParser
use Rack::Head
use Rack::ConditionalGet
use Rack::ETag
use ExceptionNotification::Rack
use Rakismet::Middleware
use ScoutApm::Middleware

Airbrake ScoutApm , .

My production.rb :

  config.middleware.use ExceptionNotification::Rack, :email => {
      :email_prefix => "[MyApp.se Exception] ",
      :sender_address => %{"Exception Notifier" <[e-mail]>},
      :exception_recipients => %w{[e-mail]}
    }

  # Taken from mailer.rb
  config.action_mailer.delivery_method = :smtp

  config.action_mailer.smtp_settings = {
    :enable_starttls_auto => false,
    :return_response => true,
    :raise_delivery_errors => true,
    :address => 'smtp.myapp.se',
    :port => 587,
    :domain => "myapp.se",
    :user_name => '[e-mail]',
    :password => ENV['MAILER_PWD'],
    :authentication => 'plain'
  } 

Great Memory Bloat Hunt , , , , , - .

? , , ? Rails ?

Answer 1

IMO - . errbit, , . , , , pushover, , , .

Answer 2

ExceptionMailer(whatever).deliver_later, , .