Runner doesn't look on shape_class of environment

[kirillantv]

Describe the bug

I use locust as library and I am investigating how to user custom load shape in this case. And seems like locust ignore shape_class in environment.

Expected behavior

Load increasing by 10 users every 30 seconds

Actual behavior

I've got only 1 user per second all the time

After approximately 2 minutes:

 Name                                                                              # reqs      # fails  |     Avg     Min     Max  Median  |   req/s failures/s
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 GET //                                                                               100     0(0.00%)  |    1105     782    2129    1000  |    0.40    0.00
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregated                                                                           100     0(0.00%)  |    1105     782    2129    1000  |    0.40    0.00

 Name                                                                              # reqs      # fails  |     Avg     Min     Max  Median  |   req/s failures/s
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 GET //                                                                               101     0(0.00%)  |    1103     782    2129    1000  |    0.50    0.00
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregated                                                                           101     0(0.00%)  |    1103     782    2129    1000  |    0.50    0.00

 Name                                                                              # reqs      # fails  |     Avg     Min     Max  Median  |   req/s failures/s
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 GET //                                                                               102     0(0.00%)  |    1103     782    2129    1000  |    0.50    0.00
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregated                                                                           102     0(0.00%)  |    1103     782    2129    1000  |    0.50    0.00

 Name                                                                              # reqs      # fails  |     Avg     Min     Max  Median  |   req/s failures/s
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 GET //                                                                               103     0(0.00%)  |    1102     782    2129    1000  |    0.50    0.00
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregated                                                                           103     0(0.00%)  |    1102     782    2129    1000  |    0.50    0.00

 Name                                                                              # reqs      # fails  |     Avg     Min     Max  Median  |   req/s failures/s
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 GET //                                                                               104     0(0.00%)  |    1100     782    2129    1000  |    0.50    0.00
----------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregated                                                                           104     0(0.00%)  |    1100     782    2129    1000  |    0.50    0.00

Steps to reproduce

This is my code:

import gevent
import math
from locust import HttpUser, task, between, constant
from locust.env import Environment
from locust.stats import stats_printer, stats_history
from locust.log import setup_logging
from locust.shape import LoadTestShape

setup_logging("INFO", None)


class StepLoadShape(LoadTestShape):

    step_time = 30
    step_load = 10
    spawn_rate = 10
    time_limit = 600

    def tick(self):
        run_time = self.get_run_time()

        if run_time > self.time_limit:
            return None

        current_step = math.floor(run_time / self.step_time) + 1
        return (current_step * self.step_load, self.spawn_rate)


class User(HttpUser):
    wait_time = constant(1)

    @task
    def my_task(self):
        self.client.get("/")


env = Environment(user_classes=[User], shape_class=StepLoadShape, host="https://docs.locust.io/")
env.create_local_runner()

gevent.spawn(stats_printer(env.stats))

gevent.spawn(stats_history, env.runner)

env.runner.start(1, spawn_rate=10)

gevent.spawn_later(600, lambda: env.runner.quit())

env.runner.greenlet.join()

Run it with python /path_to_file

Environment

• OS: macOS 10.15.4
• Python version: 3.7.11
• Locust version: 2.1.0
• Locust command line that you ran:
• Locust file contents (anonymized if necessary):

[cyberw]

@max-rocket-internet is the most load shape-y person. Do you have time to take a look?

[max-rocket-internet]

@kirillantv does it work when using it as a normal locustfile and a master + worker? i.e. remove everything after the User class. You can test this easily using docker-compose for example.

[mboutet]

@kirillantv Is this also occuring with locust 1.6?

[kirillantv]

@max-rocket-internet yeap. With normal locustfile that works.

@mboutet with locust 1.6 it is also occuring. I am also confused by runner.start(1, spawn_rate=10) - I implement all load logic in load shape, but I also must pass start param.

[mboutet]

You should use env.runner.start_shape() for load shape.

[kirillantv]

@mboutet Hm. Thanks! I also needed to pass shape_class param to env as object, not as class.
I think this method is sorely lacking in the documentation

[cyberw]

Documentation PR would be welcome. And a warning logging if someone runs runner.start() with a shape set on environment.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[github-actions]

This issue was closed because it has been stalled for 10 days with no activity. This does not necessarily mean that the issue is bad, but it most likely means that nobody is willing to take the time to fix it. If you have found Locust useful, then consider contributing a fix yourself!

[gauravmadarkal]

I still have this issue where I pass the custom load shape and call runner.start_shape(), the load test spawns 1 user every second instead of following what the load shape tells it to

load_test_shape = CustomLoadTestShape()
env = Environment(user_classes=user_classes, shape_class=load_test_shape, events=events)
runner = env.create_local_runner()
env.events.init.fire(environment=env, runner=runner)
runner.start_shape()