Class: RailsAutoscaleAgent::Request

Inherits:
Object
  • Object
show all
Includes:
Logger
Defined in:
lib/rails_autoscale_agent/request.rb

Instance Method Summary collapse

Methods included from Logger

#logger

Constructor Details

#initialize(env, config) ⇒ Request

Returns a new instance of Request.



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# File 'lib/rails_autoscale_agent/request.rb', line 9

def initialize(env, config)
  @config = config
  @id = env['HTTP_X_REQUEST_ID']
  @size = env['rack.input'].respond_to?(:size) ? env['rack.input'].size : 0
  @request_body_wait = env['puma.request_body_wait'].to_i
  @request_start_header = env['HTTP_X_REQUEST_START']
end

Instance Method Details

#ignore? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rails_autoscale_agent/request.rb', line 17

def ignore?
  @config.ignore_large_requests? && @size > @config.max_request_size
end

#queue_time(now = Time.now) ⇒ Object 



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# File 'lib/rails_autoscale_agent/request.rb', line 34

def queue_time(now = Time.now)
  return if started_at.nil?

  queue_time = ((now - started_at) * 1000).to_i

  # Subtract the time Puma spent waiting on the request body. It's irrelevant to capacity-related queue time.
  # Without this, slow clients and large request payloads will skew queue time.
  queue_time -= @request_body_wait

  logger.debug "Request queue_time=#{queue_time}ms body_wait=#{@request_body_wait}ms request_id=#{@id} size=#{@size}"

  # Safeguard against negative queue times (should not happen in practice)
  queue_time > 0 ? queue_time : 0
end

#started_at ⇒ Object 



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# File 'lib/rails_autoscale_agent/request.rb', line 21

def started_at
  if @request_start_header
    # Heroku sets the header as an integer, measured in milliseconds.
    # If nginx is involved, it might be in seconds with fractional milliseconds,
    # and it might be preceeded by "t=". We can all cases by removing non-digits
    # and treating as milliseconds.
    Time.at(@request_start_header.gsub(/\D/, '').to_i / 1000.0)
  elsif @config.dev_mode?
    # In dev mode, fake a queue time of 0-1000ms
    Time.now - rand + @request_body_wait
  end
end