load-test-scenario-builder

Load Test Scenario Builder

Validate system capacity with realistic load tests.

Load Test Scenarios

interface LoadTestScenario {
  name: string;
  description: string;
  virtualUsers: number;
  duration: string;
  rampUp: string;
  successCriteria: {
    p95Latency: number;
    errorRate: number;
    throughput: number;
  };
}

const scenarios: LoadTestScenario[] = [
  {
    name: "Baseline Load",
    description: "Normal traffic pattern",
    virtualUsers: 100,
    duration: "10m",
    rampUp: "2m",
    successCriteria: {
      p95Latency: 500, // ms
      errorRate: 0.01, // 1%
      throughput: 1000, // req/s
    },
  },
  {
    name: "Peak Load",
    description: "Black Friday traffic",
    virtualUsers: 1000,
    duration: "30m",
    rampUp: "5m",
    successCriteria: {
      p95Latency: 2000,
      errorRate: 0.05,
      throughput: 5000,
    },
  },
  {
    name: "Stress Test",
    description: "Find breaking point",
    virtualUsers: 5000,
    duration: "20m",
    rampUp: "10m",
    successCriteria: {
      p95Latency: 5000,
      errorRate: 0.1,
      throughput: 10000,
    },
  },
];

K6 Load Test Script

// load-tests/checkout-flow.js
import http from "k6/http";
import { check, sleep } from "k6";
import { Rate } from "k6/metrics";

const errorRate = new Rate("errors");

export let options = {
  stages: [
    { duration: "2m", target: 100 }, // Ramp up
    { duration: "10m", target: 100 }, // Stay at 100
    { duration: "2m", target: 0 }, // Ramp down
  ],
  thresholds: {
    http_req_duration: ["p(95)<500"], // 95% under 500ms
    errors: ["rate<0.01"], // Error rate <1%
  },
};

export default function () {
  // 1. Browse products
  let browseRes = http.get("https://api.example.com/products");
  check(browseRes, {
    "browse status 200": (r) => r.status === 200,
  }) || errorRate.add(1);
  sleep(1);

  // 2. Add to cart
  let addCartRes = http.post(
    "https://api.example.com/cart",
    JSON.stringify({
      productId: "123",
      quantity: 1,
    }),
    {
      headers: { "Content-Type": "application/json" },
    }
  );
  check(addCartRes, {
    "add cart status 201": (r) => r.status === 201,
  }) || errorRate.add(1);
  sleep(2);

  // 3. Checkout
  let checkoutRes = http.post(
    "https://api.example.com/checkout",
    JSON.stringify({
      paymentMethod: "card",
    }),
    {
      headers: { "Content-Type": "application/json" },
    }
  );
  check(checkoutRes, {
    "checkout status 200": (r) => r.status === 200,
    "checkout success": (r) => r.json("status") === "success",
  }) || errorRate.add(1);
  sleep(3);
}