tracing

README

xk6-distributed-tracing

This is a k6 extension using the xk6 system.

❗ This is a proof of concept, isn't supported by the k6 team, and may break in the future. USE AT YOUR OWN RISK!

Why?

If you're testing a system that is instrumented (with distributed tracing), you can use this extension to start the traces on k6.

The extension is built on top of OpenTelemetry, and gives k6:

• An instrumented HTTP client.
• The hability to:
  • Export spans (your tracing data).
    • Supported exporters: jaeger, zipkin, otlp, noop, stdout
  • Propagate context.
    • Supported protocols: w3c, b3, jaeger, ot

Build

To build a k6 binary with this extension, first ensure you have the prerequisites:

• Go toolchain
• Git

Then:

1. Download xk6:

$ go install github.com/k6io/xk6/cmd/xk6@latest

1. Build the binary:

$ xk6 build --with github.com/k6io/xk6-distributed-tracing@latest

Example

import tracing, { Http } from 'k6/x/tracing';
import { sleep } from 'k6';

export let options = {
  vus: 1,
  duration: '10s',
};

export function setup() {
  console.log(`Running xk6-distributed-tracing v${tracing.version}`, tracing);
}

export default function() {
  const http = new Http({
    exporter: "jaeger",
    propagator: "w3c",
    endpoint: "http://localhost:14268/api/traces"
  });
  const r = http.get('https://test-api.k6.io');
  console.log(`trace_id=${r.trace_id}`);
  sleep(1);
}

export function teardown(){
  // Cleanly shutdown and flush telemetry when k6 exits.
  tracing.shutdown();
}

Result output:

$ ./k6 run script.js

          /\      |‾‾| /‾‾/   /‾‾/   
     /\  /  \     |  |/  /   /  /    
    /  \/    \    |     (   /   ‾‾\  
   /          \   |  |\  \ |  (‾)  | 
  / __________ \  |__| \__\ \_____/ .io

  execution: local
     script: script.js
     output: -

  scenarios: (100.00%) 1 scenario, 1 max VUs, 40s max duration (incl. graceful stop):
           * default: 1 looping VUs for 10s (gracefulStop: 30s)

INFO[0000] Running xk6-distributed-tracing v0.0.2  source=console                
INFO[0000] trace-id=743fff0b96778539acb7139e72ea1e33
INFO[0001] trace-id=365f4637a52526db1de2d30a5568ca3a
INFO[0002] trace-id=c49e1df945049c5c3c8b59acc84d7d3b
INFO[0003] trace-id=53e1937d56aa172b46d2310e3380dfe9
INFO[0004] trace-id=d61e8757d35c9ca1780b88977ac56d72
INFO[0005] trace-id=358e794ed636d268a918dcd2f3f9db0a
INFO[0006] trace-id=992a959e09ee84f3905a215bec8b53a0
INFO[0007] trace-id=aee11c64de11744ab5b66d5dd8ed361b
INFO[0008] trace-id=c4dc45d857e99ede2bb902666457239d
INFO[0009] trace-id=7623d10293d9f03c15deb8055935664e

running (10.1s), 0/1 VUs, 10 complete and 0 interrupted iterations
default ✓ [======================================] 1 VUs  10s

     █ setup

     data_received..............: 1.6 kB 156 B/s
     data_sent..................: 1.7 kB 165 B/s
     http_req_blocked...........: avg=223.43µs min=146.53µs med=217.39µs max=314.54µs p(90)=276.68µs p(95)=295.61µs
     http_req_connecting........: avg=137.18µs min=87.22µs  med=130.17µs max=196.38µs p(90)=184.38µs p(95)=190.38µs
     http_req_duration..........: avg=6.58ms   min=5.07ms   med=6.45ms   max=7.91ms   p(90)=7.83ms   p(95)=7.87ms  
     http_req_receiving.........: avg=187.27µs min=94.29µs  med=171.7µs  max=295.67µs p(90)=293.28µs p(95)=294.48µs
     http_req_sending...........: avg=128.07µs min=94.64µs  med=121.77µs max=175.65µs p(90)=160.41µs p(95)=168.03µs
     http_req_tls_handshaking...: avg=0s       min=0s       med=0s       max=0s       p(90)=0s       p(95)=0s      
     http_req_waiting...........: avg=6.27ms   min=4.83ms   med=6.13ms   max=7.64ms   p(90)=7.56ms   p(95)=7.6ms   
     http_reqs..................: 10     0.991797/s
     iteration_duration.........: avg=916.48ms min=65.67µs  med=1s       max=1s       p(90)=1s       p(95)=1s      
     iterations.................: 10     0.991797/s
     vus........................: 1      min=1 max=1
     vus_max....................: 1      min=1 max=1

Documentation

Index

• type JsModule
  • func (*JsModule) Shutdown() error
  • func (*JsModule) XHttp(ctx *context.Context, opts Options) interface{}
• type Options

Types

type JsModule

type JsModule struct {
	Version string
	Http    *client.TracingClient
}

JsModule exposes the tracing client in the javascript runtime

func (*JsModule) Shutdown

func (*JsModule) Shutdown() error

func (*JsModule) XHttp

func (*JsModule) XHttp(ctx *context.Context, opts Options) interface{}

type Options

type Options struct {
	Exporter   string
	Propagator string
	Endpoint   string
}