module Datadog::Contrib::Rack::QueueTime
Retrieves the time spent in an upstream proxy for the current Rack
request.
This time captures the request delay introduced but such proxy before the request made it to the Ruby process.
Constants
- MINIMUM_ACCEPTABLE_TIME_VALUE
- QUEUE_START
- REQUEST_START
Public Instance Methods
get_request_start(env, now = Time.now.utc)
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# File lib/ddtrace/contrib/rack/request_queue.rb, line 18 def get_request_start(env, now = Time.now.utc) header = env[REQUEST_START] || env[QUEUE_START] return unless header # nginx header is seconds in the format "t=1512379167.574" # apache header is microseconds in the format "t=1570633834463123" # heroku header is milliseconds in the format "1570634024294" time_string = header.to_s.delete('^0-9') return if time_string.nil? # Return nil if the time is clearly invalid time_value = "#{time_string[0, 10]}.#{time_string[10, 6]}".to_f return if time_value.zero? || time_value < MINIMUM_ACCEPTABLE_TIME_VALUE # return the request_start only if it's lesser than # current time, to avoid significant clock skew request_start = Time.at(time_value) request_start.utc > now ? nil : request_start rescue StandardError => e # in case of an Exception we don't create a # `request.queuing` span Datadog.logger.debug("[rack] unable to parse request queue headers: #{e}") nil end