Getting Started

This guide walks you through the basics of running your first LoadDensity load test.

User types

LoadDensity ships six user templates:

  • fast_http_user — high-throughput HTTP (locust.FastHttpUser + geventhttpclient).

  • http_user — locust.HttpUser + requests.

  • websocket_user, grpc_user, mqtt_user, socket_user — see Chapter 4.

Run a test (Python API)

from je_load_density import start_test

start_test(
    user_detail_dict={"user": "fast_http_user"},
    user_count=50,
    spawn_rate=10,
    test_time=30,
    variables={"base": "https://httpbin.org"},
    tasks=[
        {"method": "get",  "request_url": "${var.base}/get"},
        {"method": "post", "request_url": "${var.base}/post",
         "json": {"hello": "world"},
         "assertions": [{"type": "status_code", "value": 200}]},
    ],
)

Launch the Locust Web UI

start_test(
    user_detail_dict={"user": "fast_http_user"},
    user_count=50, spawn_rate=10, test_time=30,
    web_ui_dict={"host": "127.0.0.1", "port": 8089},
    tasks=[{"method": "get", "request_url": "https://httpbin.org/get"}],
)

Then open http://127.0.0.1:8089 in your browser.

Run a JSON action script

Create test_scenario.json:

{"load_density": [
  ["LD_start_test", {
    "user_detail_dict": {"user": "fast_http_user"},
    "user_count": 20, "spawn_rate": 10, "test_time": 30,
    "tasks": [{"method": "get", "request_url": "https://httpbin.org/get"}]
  }],
  ["LD_generate_summary_report", {"report_name": "smoke"}]
]}

Execute via the CLI:

python -m je_load_density run test_scenario.json

Or from Python:

from je_load_density import execute_action, read_action_json
execute_action(read_action_json("test_scenario.json"))

JSON script format

Each action is a list:

  • with keyword arguments: ["action_name", {"param1": "value1"}]

  • with positional arguments: ["action_name", ["arg1", "arg2"]]

  • with no arguments: ["action_name"]

The top-level document is either a bare action list or a {"load_density": [...]} wrapper.

Next steps