https://grafana.com/docs/k6/latest/get-started

install and run

1. install

# mac
brew install k6

2. 当前目录下生成压测脚本

# create file script.js
k6 new [filename]     # create file ‘script.js’ in the current directory

3 run

k6 run script.js

4. reports
   默认情况下，k6 将总结结果打印到 stdout 。

script.js

import http from 'k6/http';
import { check, sleep } from 'k6';

export const options = {
  vus: 10,
  duration: '30s',
};

export default function () {
  const res = http.get('http://test.k6.io');
  check(res, { 'status was 200': (r) => r.status == 200 });
  sleep(1);
}

options

https://grafana.com/docs/k6/latest/using-k6/k6-options/reference/

• vus
  虚拟用户数
• duration
  持续时间
• rps
  每秒请求数量

请求总数 = vus * rps * durance（s）

import http from 'k6/http';
import { check, sleep } from 'k6';

export const options = {
  maxRedirects: 4,
  duration: '300s',
  vus: 10,
  rps: 300
};

// stages : 逐步提升/降低 
export const options = {
  stages: [
    { target: 200, duration: '30s' },
    { target: 0, duration: '30s' },
  ],
};

export const options = {
  stages: [
    { duration: '10s', target: 100 },
    { duration: '5m', target: 100 },
    { duration: '10s', target: 0 },
  ],
  rps: 100,
};

最佳实践

VUs太大的情况下, 直接启动所有 VUs 会几乎同时发起请求，导致请求的瞬间激增。这样的突发性负载可能会导致系统未能及时响应，进而出现错误。
改为 分阶段增加 VUs , 系统逐步适应增加的负载

report 解析

默认report

         /\      Grafana   /‾‾/  
    /\  /  \     |\  __   /  /   
   /  \/    \    | |/ /  /   ‾‾\ 
  /          \   |   (  |  (‾)  |
 / __________ \  |_|\_\  \_____/ 

     execution: local
        script: script.js
        output: -

     scenarios: (100.00%) 1 scenario, 2000 max VUs, 1m15s max duration (incl. graceful stop):
              * default: Up to 2000 looping VUs for 45s over 6 stages (gracefulRampDown: 30s, gracefulStop: 30s)


     ✓ status is 200

     checks.........................: 100.00% 191878 out of 191878
     data_received..................: 160 MB  3.5 MB/s
     data_sent......................: 20 MB   443 kB/s
     http_req_blocked...............: avg=5.84µs   min=0s    med=1µs      max=9.49ms  p(90)=4µs      p(95)=7µs     
     http_req_connecting............: avg=2.71µs   min=0s    med=0s       max=9.43ms  p(90)=0s       p(95)=0s      
     http_req_duration..............: avg=246.16ms min=383µs med=103.16ms max=6.91s   p(90)=617.17ms p(95)=979.14ms
       { expected_response:true }...: avg=246.16ms min=383µs med=103.16ms max=6.91s   p(90)=617.17ms p(95)=979.14ms
     http_req_failed................: 0.00%   0 out of 191878
     http_req_receiving.............: avg=40.53µs  min=5µs   med=18µs     max=65.69ms p(90)=74µs     p(95)=102.14µs
     http_req_sending...............: avg=10.06µs  min=1µs   med=3µs      max=53.75ms p(90)=15µs     p(95)=23µs    
     http_req_tls_handshaking.......: avg=0s       min=0s    med=0s       max=0s      p(90)=0s       p(95)=0s      
     http_req_waiting...............: avg=246.11ms min=373µs med=103.09ms max=6.91s   p(90)=617.11ms p(95)=979.11ms
     http_reqs......................: 191878  4263.707029/s
     iteration_duration.............: avg=246.24ms min=406µs med=103.26ms max=6.91s   p(90)=617.2ms  p(95)=979.24ms
     iterations.....................: 191878  4263.707029/s
     vus............................: 7       min=7                max=1990
     vus_max........................: 2000    min=2000             max=2000


running (0m45.0s), 0000/2000 VUs, 191878 complete and 0 interrupted iterations
default ✓ [======================================] 0000/2000 VUs  45s

总请求量 191878, 持续时间 45.0s
p(95)=979.14ms : 95% 的请求响应时间在 979.14ms 以内