Load tests development for website (Artillery)

Load Testing Development for Websites (Artillery)

Artillery is a Node.js load testing tool with YAML/JSON configuration. Supports HTTP and WebSocket, easily integrates into CI/CD, has extensions for custom JS scenarios.

Installation

npm install -g artillery

Basic Scenario

# tests/load/basic.yml
config:
  target: "https://staging.example.com"
  phases:
    - duration: 60
      arrivalRate: 5     # 5 new users per second
      name: Warm up
    - duration: 120
      arrivalRate: 20
      name: Ramp up load
    - duration: 300
      arrivalRate: 50
      name: Sustained load
    - duration: 60
      arrivalRate: 100
      name: Stress test

  defaults:
    headers:
      Accept: "application/json"
      Content-Type: "application/json"

  ensure:
    p99: 1000     # 99th percentile < 1000ms
    p95: 500
    maxErrorRate: 1  # less than 1% errors

scenarios:
  - name: Browse catalog
    weight: 60      # 60% of traffic
    flow:
      - get:
          url: "/api/products"
          expect:
            - statusCode: 200
            - hasProperty: "data"
      - think: 2
      - get:
          url: "/api/products/{{ $randomNumber(1, 100) }}"

  - name: Search
    weight: 30
    flow:
      - get:
          url: "/api/search?q={{ $randomString() }}"
          expect:
            - statusCode: [200, 404]

  - name: Contact form
    weight: 10
    flow:
      - post:
          url: "/api/contact"
          json:
            name: "Test User"
            email: "[email protected]"
            message: "Load test message"
          expect:
            - statusCode: 201

Scenario with Authorization

# tests/load/authenticated.yml
config:
  target: "https://staging.example.com"
  phases:
    - duration: 300
      arrivalRate: 20
  variables:
    users:
      - email: "[email protected]"
        password: "pass123"
      - email: "[email protected]"
        password: "pass456"

scenarios:
  - name: Authenticated user flow
    flow:
      - post:
          url: "/api/auth/login"
          json:
            email: "{{ users[0].email }}"
            password: "{{ users[0].password }}"
          capture:
            - json: "$.access_token"
              as: "token"
          expect:
            - statusCode: 200

      - get:
          url: "/api/user/profile"
          headers:
            Authorization: "Bearer {{ token }}"
          expect:
            - statusCode: 200

      - post:
          url: "/api/orders"
          headers:
            Authorization: "Bearer {{ token }}"
          json:
            product_id: 1
            quantity: 1
          expect:
            - statusCode: 201
          capture:
            - json: "$.id"
              as: "orderId"

      - get:
          url: "/api/orders/{{ orderId }}"
          headers:
            Authorization: "Bearer {{ token }}"
          expect:
            - statusCode: 200

Custom JS Processor

# tests/load/custom.yml
config:
  processor: "./processor.js"

scenarios:
  - name: Dynamic flow
    flow:
      - function: "generateDynamicPayload"
      - post:
          url: "/api/data"
          json: "{{ payload }}"

// processor.js
module.exports = { generateDynamicPayload };

function generateDynamicPayload(context, events, done) {
    context.vars.payload = {
        id: Math.floor(Math.random() * 10000),
        timestamp: new Date().toISOString(),
        data: Array.from({ length: 10 }, (_, i) => ({ key: `item_${i}`, value: Math.random() })),
    };
    return done();
}

Running and Reports

# Basic run
artillery run tests/load/basic.yml

# JSON report
artillery run --output report.json tests/load/basic.yml
artillery report report.json  # generates HTML

# Run with environment variables
artillery run \
    --target https://staging.example.com \
    --overrides '{"config": {"phases": [{"duration": 60, "arrivalRate": 10}]}}' \
    tests/load/basic.yml

GitHub Actions

- name: Load Test
  run: |
    artillery run --output results.json tests/load/basic.yml
    artillery report --output load-report.html results.json

- name: Check SLA
  run: |
    ERRORS=$(cat results.json | jq '.aggregate.counters["http.codes.5xx"] // 0')
    P99=$(cat results.json | jq '.aggregate.latency.p99')
    if [ "$ERRORS" -gt "10" ] || [ "$(echo "$P99 > 2000" | bc)" = "1" ]; then
      echo "Load test failed: too many errors or high latency"
      exit 1
    fi

Implementation Timeline

Writing 3–5 load testing scenarios with Artillery: 2–3 days.