k6 是GitHub上提供的开源负载测试工具，使用Go编写。测试脚本使用JavaScript编写。

先决条件#

安装K6 https://k6.io/docs/getting-started/installation
环境变量配置；cd 到压测脚本目录

概念#

vu：虚拟用户
duration:持续时长

入门#

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

export default function() {
  http.get('http://localhost:5000/api/values');
}

k6 run ValuesApiK6.js

多Vu和指定时长#

k6 run --vus 10 --duration 10s ValuesApiK6.js

使用配置选项#

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

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

// 脚本至少必须包含一个default函数,这定义了VU的入口点，类似于许多其他语言中的main()函数
export default function() {
  let res = http.get("http://localhost:5000/api/values");
  check(res, { 'status was 200': r => r.status == 200 });
  sleep(1);
}

阶段负载#

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

export let options = {
  // 阶段负载
  stages: [
    { duration: "3s", target: 2 },
    { duration: "5s", target: 3 },
    { duration: "6s", target: 10 },
  ],
};

// 脚本至少必须包含一个default函数,这定义了VU的入口点，类似于许多其他语言中的main()函数
export default function () {
  let res = http.get("http://localhost:5000/api/values");
  check(res, { "status was 200": (r) => r.status == 200 });
  sleep(1);
}

可能出现的异常：using multiple execution config shortcuts (durationandstages) simultaneously is not allowed 不允许同时使用多个执行配置快捷方式(“duration”和“stages”)。

断言#

需要import { sleep, check } from "k6"; 引入check模块。

check(res, { "status was 200": (r) => r.status == 200 });

测试结果#

 execution: local-
     script: ValuesApiK6.js
     output: -

  scenarios: (100.00%) 1 executors, 10 max VUs, 44s max duration (incl. graceful stop):
           * default: Up to 10 looping VUs for 14s over 3 stages (gracefulRampDown: 30s, gracefulStop: 30s)

I
running (16.0s), 00/10 VUs, 38 complete and 0 interrupted iterations
default ✓ [======================================] 00/10 VUs  14s9


    ✓ status was 200 
 
    checks.....................: 100.00% ✓ 38   ✗ 0
    data_received..............: 176 MB  11 MB/s
    data_sent..................: 3.3 kB  208 B/s
    http_req_blocked...........: avg=79.1µs   min=0s       med=0s       max=2ms     p(90)=0s      p(95)=149.71µs
    http_req_connecting........: avg=52.85µs  min=0s       med=0s       max=1.01ms  p(90)=0s      p(95)=149.71µs
    http_req_duration..........: avg=682.14ms min=332.4ms  med=516.59ms max=1.66s   p(90)=1.22s   p(95)=1.44s
    http_req_receiving.........: avg=10.39ms  min=3.98ms   med=8.97ms   max=37.89ms p(90)=16.85ms p(95)=23.37ms
    http_req_sending...........: avg=0s       min=0s       med=0s       max=0s      p(90)=0s      p(95)=0s
    http_req_tls_handshaking...: avg=0s       min=0s       med=0s       max=0s      p(90)=0s      p(95)=0s
    http_req_waiting...........: avg=671.75ms min=323.42ms med=508.61ms max=1.65s   p(90)=1.21s   p(95)=1.43s
    http_reqs..................: 38      2.374567/s
    iteration_duration.........: avg=1.68s    min=1.33s    med=1.51s    max=2.66s   p(90)=2.22s   p(95)=2.44s
    iterations.................: 38      2.374567/s
    vus........................: 0       min=0  max=9
    vus_max....................: 10      min=10 max=10

测试细节

execution k6执行模式（本地或云）
output 测试结果的输出。默认值为stdout
script: script.js 显示正在执行的脚本的名称
duration 测试运行时间
iterations VU 迭代的总数
vus 测试将开始运行的VU的初始数量
max 测试将扩展的VU的最大数量

测试指标分析参考：https://k6.io/docs/using-k6/metrics

测试结果输出第三方平台#

参考：https://k6.io/docs/getting-started/results-output#output-plugins

输出Json格式#

k6 run --summary-export=export.json test.js

输出JSON格式详细信息#

使用 --out/-o 选项使k6输出JSON格式的详细统计信息

k6 run --out json=my_test_result.json test.js

tags打标签分组#

参考：https://k6.io/docs/using-k6/http-requests#url-grouping

K6内置指标#

参考：https://k6.io/docs/using-k6/metrics#custom-metrics

HTTP内置指标#

参考：https://k6.io/docs/using-k6/metrics#metric-types

阈值#

阈值是通过/失败标准，用于指定被测系统的性能期望

预期示例（阈值）：

系统产生的错误不超过1％
95％的请求的响应时间应小于200ms
99％的请求的响应时间应低于400毫秒
特定端点必须始终在300毫秒内响应
阈值分析性能指标并确定最终测试结果（通过/失败）。阈值对于负载测试自动化至关重要

压力测试k6