Locust访问Web界面时触发AttributeError异常问题

问题详情 #

我有一个之前能正常运行的基础Locust负载测试脚本，代码如下：

from locust import HttpUser, between, task


class QuickstartUser(HttpUser):
    wait_time = between(1, 5)

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

执行命令：

locust -f <package-name>/tests/load_tests.py -r 20 -u 400 -H http://localhost:8000

访问Web界面时触发如下错误：

[2022-12-28 23:23:30,962] MacBook-Pro.fritz.box/INFO/locust.main: Starting web interface at http://0.0.0.0:8089 (accepting connections from all network interfaces)
[2022-12-28 23:23:30,968] MacBook-Pro.fritz.box/INFO/locust.main: Starting Locust 2.14.0
Traceback (most recent call last):
  File "src/gevent/greenlet.py", line 906, in gevent._gevent_cgreenlet.Greenlet.run
  File "/Users/<user>/Coding/PycharmProjects/<project>-fastapi/.venv/lib/python3.10/site-packages/gevent/baseserver.py", line 34, in _handle_and_close_when_done
    return handle(*args_tuple)
  File "/Users/<user>/Coding/PycharmProjects/<project>-fastapi/.venv/lib/python3.10/site-packages/gevent/pywsgi.py", line 1577, in handle
    handler.handle()
  File "/Users/<user>/Coding/PycharmProjects/<project>-fastapi/.venv/lib/python3.10/site-packages/gevent/pywsgi.py", line 464, in handle
    result = self.handle_one_request()
  File "/Users/<user>/Coding/PycharmProjects/<project>-fastapi/.venv/lib/python3.10/site-packages/gevent/pywsgi.py", line 656, in handle_one_request
    if self.rfile.CLOSED:
AttributeError: '_io.BufferedReader' object has no attribute 'CLOSED'
2022-12-28T22:23:35Z <Greenlet at 0x106fbc3a0: _handle_and_close_when_done(<bound method WSGIServer.handle of <WSGIServer at , <bound method StreamServer.do_close of <WSGIServer, (<gevent._socket3.socket [closed] at 0x106fcb460 o)> failed with AttributeError

当前环境依赖树（通过poetry show locust --tree获取）：

locust 2.14.0 开发者友好的负载测试框架
├── configargparse >=1.0
├── flask >=2.0.0
│   ├── click >=8.0 
│   │   └── colorama * 
│   ├── itsdangerous >=2.0 
│   ├── jinja2 >=3.0 
│   │   └── markupsafe >=2.0 
│   └── werkzeug >=2.2.2 
│       └── markupsafe >=2.1.1 (循环依赖已中止)
├── flask-basicauth >=0.2.0
│   └── flask * 
│       ├── click >=8.0 
│       │   └── colorama * 
│       ├── itsdangerous >=2.0 
│       ├── jinja2 >=3.0 
│       │   └── markupsafe >=2.0 
│       └── werkzeug >=2.2.2 
│           └── markupsafe >=2.1.1 (循环依赖已中止)
├── flask-cors >=3.0.10
│   ├── flask >=0.9 
│   │   ├── click >=8.0 
│   │   │   └── colorama * 
│   │   ├── itsdangerous >=2.0 
│   │   ├── jinja2 >=3.0 
│   │   │   └── markupsafe >=2.0 
│   │   └── werkzeug >=2.2.2 
│   │       └── markupsafe >=2.1.1 (循环依赖已中止)
│   └── six * 
├── gevent >=20.12.1
│   ├── cffi >=1.12.2 
│   │   └── pycparser * 
│   ├── greenlet >=2.0.0 
│   ├── setuptools * 
│   ├── zope-event * 
│   │   └── setuptools * (循环依赖已中止)
│   └── zope-interface * 
│       └── setuptools * (循环依赖已中止)
├── geventhttpclient >=2.0.2
│   ├── brotli * 
│   ├── certifi * 
│   ├── gevent >=0.13 
│   │   ├── cffi >=1.12.2 
│   │   └── pycparser * 
│   ├── greenlet >=2.0.0 
│   ├── setuptools * 
│   ├── zope-event * 
│   │   └── setuptools * (循环依赖已中止)
│   └── zope-interface * 
│       └── setuptools * (循环依赖已中止)
│   └── six * 
├── msgpack >=0.6.2
├── psutil >=5.6.7
├── pywin32 *
├── pyzmq >=22.2.1,<23.0.0 || >23.0.0
│   ├── cffi * 
│   │   └── pycparser * 
│   └── py * 
├── requests >=2.23.0
│   ├── certifi >=2017.4.17 
│   ├── charset-normalizer >=2,<3 
│   ├── idna >=2.5,<4 
│   └── urllib3 >=1.21.1,<1.27 
├── roundrobin >=0.0.2
├── typing-extensions >=3.7.4.3
└── werkzeug >=2.0.0
    └── markupsafe >=2.1.1 

解决方案 #

这个错误是gevent与Python 3.10的兼容性问题导致的——旧版本gevent的pywsgi模块会尝试访问_io.BufferedReader对象的CLOSED属性，但Python 3.10里该对象并没有这个属性。

解决步骤：

• 升级gevent到22.10.2或更高版本，该版本修复了Python 3.10下的这个适配问题
• 执行以下命令更新依赖：

poetry add gevent>=22.10.2

• 重新运行Locust命令即可恢复正常

内容的提问来源于stack exchange，提问作者Daniel