Fail ratio calculation for individual requests is incorrect

[genericmoniker]

Description of issue

The fail ratio for each individual request is incorrect, and doesn't match the total fail ratio.

Expected behavior

The fail ratio is correct.

Actual behavior

The fail ratio is incorrect. For example, if 10 out of 10 requests fail, I'd expect the ratio to be 100%, but instead it is 50%.

 Name                                                          # reqs      # fails     Avg     Min     Max  |  Median   req/s               
--------------------------------------------------------------------------------------------------------------------------------------------
 GET /                                                             10   10(50.00%)    2014    2009    2021  |    2000    0.75               
--------------------------------------------------------------------------------------------------------------------------------------------
 Total                                                             10  10(100.00%)                                       0.75               

Environment settings

• OS: Windows/Linux
• Python version: 3.6
• Locust version: 0.11.0

Steps to reproduce (for bug reports)

Create a trivial locustfile.py:

from locust import HttpLocust, TaskSet, task

class UserBehavior(TaskSet):
    @task
    def index(self):
        self.client.get("/")


class WebsiteUser(HttpLocust):
    task_set = UserBehavior

Run it against a host that doesn't have a web server running at all:

locust --host http://localhost --no-web --clients=10 --hatch-rate=2 --run-time=30

All of the "GET /" requests fail, but the stats (as shown above) have the failure rate at 50% rather than 100%.

I think the problem is at stats.py:279:

            return float(self.num_failures) / (self.num_requests + self.num_failures)

It seems like it ought to be:

            return float(self.num_failures) / (self.num_requests)

Maybe at some point self.num_requests was only the count of successful requests?

[cgoldberg]

Maybe at some point self.num_requests was only the count of successful requests?

good catch.. I believe it was.

Do you want to submit a Pull Request with your fix? (If not, I can take care of it)

[genericmoniker]

Sure, I can make a PR.

[cgoldberg]

thanks

[obaranov]

Hi guys. Do you have any plans to release that fix? From pip we still get v0.11.0, which is affected by that issue?