lambda

lambda.rb

require 'aws-xray-sdk'

def random_sleep_under_1s
  r = Random.rand
  sleep r
  r
end

def xray(segment_name, method_name, with_subsegments: true)
  parent_id = ENV['_X_AMZN_TRACE_ID'].gsub(/.*Parent=/, '').split(';').first
  trace_id = ENV['_X_AMZN_TRACE_ID'].gsub(/.*Root=/, '').split(';').first

  # this is how you start a segment
  segment = XRay.recorder.begin_segment(segment_name, trace_id: trace_id, parent_id: parent_id)

  if with_subsegments
    1.upto(2).each do |i|
      XRay.recorder.capture("subsegment_#{i}_#{segment_name}", segment: segment) do |subsegment|
        ret = send(method_name) # here we do some work that we want to measure
        subsegment.annotations[:return_value] = ret
        ret
      end
    end
  else
    ret = send(method_name) # here we do some work that we want to measure
    segment.annotations[:return_value] = ret # this annotation will be applied to segment
    ret
  end

  XRay.recorder.end_segment
end

def handler(event:, context:)
  xray('random_sleep_1', :random_sleep_under_1s)
  xray('random_sleep_2', :random_sleep_under_1s)

  { body: 'hello world!' }
end