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AWS X-Ray
Developer Guide

Tracing Calls to Downstream HTTP Web Services Using the X-Ray SDK for Node.js

When your application makes calls to microservices or public HTTP APIs, you can use the X-Ray SDK for Node.js client to instrument those calls and add the API to the service graph as a downstream service.

Pass your http or https client to the X-Ray SDK for Node.js captureHTTPs method to trace outgoing calls.

Example app.js - HTTP Client

var AWSXRay = require('aws-xray-sdk');
var http = AWSXRay.captureHTTPs(require('http'));

To enable tracing on all HTTP clients, call captureHTTPsGlobal before you load http.

Example app.js - HTTP Client (Global)

var AWSXRay = require('aws-xray-sdk');
AWSXRay.captureHTTPsGlobal(require('http'));
var http = require('http');

When you instrument a call to a downstream web API, the X-Ray SDK for Node.js records a subsegment that contains information about the HTTP request and response. X-Ray uses the subsegment to generate an inferred segment for the remote API.

Example Subsegment for a Downstream HTTP Call

{
  "id": "004f72be19cddc2a",
  "start_time": 1484786387.131,
  "end_time": 1484786387.501,
  "name": "names.example.com",
  "namespace": "remote",
  "http": {
    "request": {
      "method": "GET",
      "url": "https://names.example.com/"
    },
    "response": {
      "content_length": -1,
      "status": 200
    }
  }
}

Example Inferred Segment for a Downstream HTTP Call

{
  "id": "168416dc2ea97781",
  "name": "names.example.com",
  "trace_id": "1-5880168b-fd5153bb58284b67678aa78c",
  "start_time": 1484786387.131,
  "end_time": 1484786387.501,
  "parent_id": "004f72be19cddc2a",
  "http": {
    "request": {
      "method": "GET",
      "url": "https://names.example.com/"
    },
    "response": {
      "content_length": -1,
      "status": 200
    }
  },
  "inferred": true
}