ahus1/junit-load-test

Using unit test for load testing

This explores the idea of using tests based on JUnit for load testing.

• JUnit tests run from the IDE so you can develop their functional completeness
• They offer us to include all Java libraries that we need
• With JDK 21, we have virtual threads and can run them in a non-blocking way
• Vegata shows what an output format can look like, and also provides statistics

What to see here:

TestLogin.java: A unit test (which for now only calls a URL)

BaseClass.java: Provides means to instrument the HTTP client to write a JSON file in the Vegata format

Main.java: Run test in a JUnit

Examples

plotJava.html: Example chart with durations

Output of cat out.json | vegeta report:

Requests      [total, rate, throughput]         1920, 305.44, 305.34
Duration      [total, attack, wait]             6.288s, 6.286s, 2.043ms
Latencies     [min, mean, 50, 90, 95, 99, max]  368.245µs, 18.431ms, 4.705ms, 49.09ms, 85.98ms, 200.807ms, 246.887ms
Bytes In      [total, mean]                     0, 0.00
Bytes Out     [total, mean]                     0, 0.00
Success       [ratio]                           100.00%
Status Codes  [code:count]                      200:640  302:1280  
Error Set:

Output of cat out.json | vegeta report --type=json | jq:

{
  "latencies": {
    "total": 35388185871,
    "mean": 18431346,
    "50th": 4704775,
    "90th": 49089834,
    "95th": 85980422,
    "99th": 200807282,
    "max": 246887483,
    "min": 368245
  },
  "bytes_in": {
    "total": 0,
    "mean": 0
  },
  "bytes_out": {
    "total": 0,
    "mean": 0
  },
  "earliest": "2025-04-10T13:25:59.823879076Z",
  "latest": "2025-04-10T13:26:06.109878634Z",
  "end": "2025-04-10T13:26:06.111921615Z",
  "duration": 6285999558,
  "wait": 2042981,
  "requests": 1920,
  "rate": 305.4406832651578,
  "throughput": 305.34144578248055,
  "success": 1,
  "status_codes": {
    "200": 640,
    "302": 1280
  },
  "errors": []
}

Reference

Vegeta: https://github.com/tsenart/vegeta

Example scripts

echo "GET http://localhost:8080" | vegeta attack -name=50qps -rate=50 -duration=5s > results.50qps.bin
cat results.50qps.bin | vegeta plot > plot.50qps.html

echo "GET http://localhost:8080" | vegeta attack -name=100qps -rate=100 -duration=5s > results.100qps.bin

vegeta plot results.50qps.bin results.100qps.bin > plot.html

cat results.50qps.bin results.100qps.bin | vegeta report

vegeta encode results.50qps.bin | vegeta plot > plotJson.html

cat out.json | vegeta plot > plotJava.html