How to set transactions per minute in Locust-CodePudding

I am writing a LoadTestShape Class. I want to be able to set number of transaction per minute. If I try to set it by specifying user_count it doesn't work because the RPS will vary cpu to cpu .

If say I want to set 1000 transaction per minute, how can we achieve that in locust?

CodePudding user response：

The only way to "achieve" this in Locust is implementing Pacing, the logic is:

You know how much time one iteration takes for one user
If user manages to finish faster - you need to introduce some "think time" so your thread "sleeps" till the desired time
If iteration is slower - no sleep is required.

This answer shows how you can create a custom load shape

Alternatively you can consider switching to a load testing tool which provides such functionality, i.e. Apache JMeter with Constant Throughput Timer

CodePudding user response：

for this timing that's enough to add a LoadTestShape class to locustfile.py like the below code which I use for one of my tests you can change the number of users or other parameters as you want(I write a full docstring that describes each parameter in that):

class StagesShape(LoadTestShape):
    """
    A simply load test shape class that has different user and spawn_rate at
    different stages.
    Keyword arguments:
        stages -- A list of dicts, each representing a stage with the following keys:
            duration -- When this many seconds pass the test is advanced to the next stage
            users -- Total user count
            spawn_rate -- Number of users to start/stop per second
            stop -- A boolean that can stop that test at a specific stage
        stop_at_end -- Can be set to stop once all stages have run.
    """

    stages = [
        {"duration": 60, "users": 3, "spawn_rate": 0.05},
        {"duration": 60, "users": 6, "spawn_rate": 0.05},
        {"duration": 60, "users": 9, "spawn_rate": 0.05},
        {"duration": 60, "users": 12, "spawn_rate": 0.05},
        {"duration": 60, "users": 15, "spawn_rate": 0.05},
        {"duration": 60, "users": 18, "spawn_rate": 0.05},
        {"duration": 60, "users": 21, "spawn_rate": 0.05},
        {"duration": 60, "users": 24, "spawn_rate": 0.05},
        {"duration": 60, "users": 27, "spawn_rate": 0.05},
        {"duration": 60, "users": 30, "spawn_rate": 0.05},
    ]

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

        for stage in self.stages:
            if run_time < stage["duration"]:
                tick_data = (stage["users"], stage["spawn_rate"])
                return tick_data

        return None