K6 + JavaScript 压测服务端

K6是一款现代化的开源负载测试工具，专为开发和测试人员设计，可以使用JavaScript编写测试脚本。以下是完整的K6压测教程。

一、安装K6

下载地址
官网

二、编写第一个测试脚本

创建一个名为test.js的文件：

import http from 'k6/http';
import { check, sleep } from 'k6';// 初始化选项
export let options = {vus: 10,            // 虚拟用户数duration: '30s',    // 测试持续时间
};export default function () {// 发送HTTP GET请求let res = http.get('https://test-api.k6.io/public/crocodiles/');// 验证响应状态码是否为200check(res, {'is status 200': (r) => r.status === 200,});// 每个VU每次迭代后暂停1秒sleep(1);
}

三、运行测试

在终端运行：

k6 run test.js

四、进阶测试脚本

1. 带参数的POST请求

import http from 'k6/http';
import { check, sleep } from 'k6';export let options = {stages: [{ duration: '30s', target: 20 },  // 30秒内逐步增加到20个VU{ duration: '1m', target: 20 },    // 保持20个VU1分钟{ duration: '30s', target: 0 },    // 30秒内逐步减少到0],
};export default function () {// POST请求数据let data = JSON.stringify({username: 'test_user',password: 'test_password',});let params = {headers: {'Content-Type': 'application/json',},};let res = http.post('https://test-api.k6.io/auth/token/login/', data, params);check(res, {'login successful': (r) => r.status === 200,'response time < 500ms': (r) => r.timings.duration < 500,});sleep(1);
}

2. 使用CSV数据驱动测试

创建users.csv文件：

username,password
user1,pass1
user2,pass2
user3,pass3

测试脚本：

import http from 'k6/http';
import { check, sleep } from 'k6';
import { SharedArray } from 'k6/data';// 读取CSV文件
const users = new SharedArray('users', function () {return open('./users.csv').split('\n').slice(1).map((line) => {const parts = line.split(',');return { username: parts[0], password: parts[1] };});
});export let options = {vus: 10,duration: '1m',
};export default function () {// 获取当前VU的用户数据const user = users[__VU % users.length];let data = JSON.stringify({username: user.username,password: user.password,});let params = {headers: {'Content-Type': 'application/json',},};let res = http.post('https://test-api.k6.io/auth/token/login/', data, params);check(res, {'login successful': (r) => r.status === 200,});sleep(1);
}

3. 测试RESTful API完整流程

import http from 'k6/http';
import { check, group, sleep } from 'k6';export let options = {stages: [{ duration: '30s', target: 20 },{ duration: '1m', target: 50 },{ duration: '20s', target: 0 },],thresholds: {http_req_duration: ['p(95)<500'], // 95%的请求响应时间应小于500ms'logged in successfully': ['rate>0.9'], // 登录成功率应大于90%},
};export default function () {// 1. 登录获取tokengroup('Authentication', function () {let loginRes = http.post('https://test-api.k6.io/auth/token/login/', {username: 'test_user',password: 'test_password',});check(loginRes, {'logged in successfully': (resp) => resp.json('access') !== '',});let authHeaders = {headers: {Authorization: `Bearer ${loginRes.json('access')}`,},};// 2. 获取用户信息let userRes = http.get('https://test-api.k6.io/auth/users/me/', authHeaders);check(userRes, {'retrieved user info': (r) => r.status === 200,});// 3. 创建资源let createRes = http.post('https://test-api.k6.io/public/crocodiles/',{name: `Croc_${__VU}_${__ITER}`,sex: 'M',date_of_birth: '2020-01-01',},authHeaders);check(createRes, {'created resource': (r) => r.status === 201,});let crocId = createRes.json('id');// 4. 获取创建的资源let getRes = http.get(`https://test-api.k6.io/public/crocodiles/${crocId}/`, authHeaders);check(getRes, {'retrieved created resource': (r) => r.status === 200,});// 5. 删除资源let deleteRes = http.del(`https://test-api.k6.io/public/crocodiles/${crocId}/`, null, authHeaders);check(deleteRes, {'deleted resource': (r) => r.status === 204,});});sleep(1);
}

五、结果分析与可视化

1. 输出结果到文件

k6 run --out json=result.json test.js
k6 run --out csv=result.csv test.js

2. 使用InfluxDB和Grafana可视化

1. 安装InfluxDB和Grafana
2. 运行测试时将结果发送到InfluxDB：

   k6 run --out influxdb=http://localhost:8086/k6 test.js
   

3. 在Grafana中配置InfluxDB数据源
4. 导入K6仪表板模板

3. 使用k6 Cloud

如果你使用k6 Cloud，可以直接：

k6 login cloud --token YOUR_TOKEN
k6 cloud test.js

六、高级功能

1. 自定义指标

import http from 'k6/http';
import { check, sleep, group, trend } from 'k6';// 创建自定义趋势指标
let responseTrend = new trend('response_time');export let options = {vus: 10,duration: '1m',
};export default function () {group('API Test', function () {let res = http.get('https://test-api.k6.io/public/crocodiles/');// 记录响应时间到自定义指标responseTrend.add(res.timings.duration);check(res, {'is status 200': (r) => r.status === 200,'response time < 500ms': (r) => r.timings.duration < 500,});});sleep(1);
}

2. 使用WebSocket

import ws from 'k6/ws';
import { check, sleep } from 'k6';export let options = {vus: 10,duration: '30s',
};export default function () {let url = 'ws://echo.websocket.org';let response = ws.connect(url, null, function (socket) {socket.on('open', function open() {socket.send('hello');});socket.on('message', function (message) {console.log('Received: ', message);socket.close();});socket.on('close', function () {console.log('disconnected');});});check(response, { 'status is 101': (r) => r && r.status === 101 });sleep(1);
}

3. 分布式测试

使用k6 Operator在Kubernetes集群上运行分布式测试：

1. 安装k6 Operator
2. 创建测试资源文件test.yaml：

   apiVersion: k6.io/v1alpha1
   kind: K6
   metadata:name: k6-sample-test
   spec:parallelism: 4script:configMap:name: k6-test-scriptfile: test.js
   

3. 应用配置：

   kubectl apply -f test.yaml
   

七、常见问题解决

1. 连接被拒绝：检查目标服务是否运行，防火墙设置
2. SSL证书问题：添加insecureSkipTLSVerify: true到请求参数
3. 内存不足：减少VU数量或增加batch/batchPerHost参数
4. 结果不一致：确保测试环境稳定，避免网络波动

通过以上教程，你可以使用K6和JavaScript编写全面的服务端压力测试脚本，并根据测试结果优化系统性能。