Chaos工具包未重命名文件

Question

我正在学习混沌工程，我正在学习一个教程，但我的代码没有正常运行。

我正在测试的服务。

service.py

import io
import time
import threading
from wsgiref.validate import validator
from wsgiref.simple_server import make_server
EXAMPLE_FILE = './example.dat'
def update_file():
"""Write the current time to the file every second."""
print('Updating file...')
while True:
with open(EXAMPLE_FILE, 'w') as f:
f.write(datetime.now().isoformat())
time.sleep(1)
def simple_app(environ, start_response):
"""A simple WSGI application.
This application just writes the current time to the response.
"""
status = '200 OK'
headers = [('Content-type', 'text/plain; charset=utf-8')]
start_response(status, headers)
with open(EXAMPLE_FILE, 'r') as f:
return [f.read().encode('utf-8')]
if __name__ == '__main__':
# Start the file update thread.
t = threading.Thread(target=update_file)
t.start()
httpd = make_server('', 8000, simple_app)
print("Serving on port 8000...")
try:
httpd.serve_forever()
except KeyboardInterrupt:
print("nKeyboard interrupt received, exiting.")
httpd.shutdown()
t.join(timeout=1)
print("Exiting.")

我的混沌实验文件experiment.json

"title": "Does our service tolerate the loss of its example file?",
"description": "Our service reads data from a file, can it work without it?",
"tags": ["tutorial", "filesystem"],
"steady-state-hypothesis": {
"title": "The exchange file must exist",
"probes": [
{
"type": "probe",
"name": "service-is-unavailable",
"tolerance": [200, 503],
"provider": {
"type": "http",
"url": "http://localhost:8000"
}
}
]
},
"method": [
{
"name": "move-example-file",
"type": "action",
"provider": {
"type": "python",
"module": "os",
"func": "rename",
"arguments": {
"src": "./example.dat",
"dst": "./example.dat.old"
}
}
}
]
}

但是，混乱并没有重命名我的旧文件，而是用提供的名称创建了一个新文件，实验以成功告终，这是我没有预料到的。

在此处输入图像描述

请帮忙。

Answer 1

终于来了！

问题：update_file每秒更新一次example.dat文件，如果它不存在，它只会创建它！因此，当chaos将example.dat重命名为example.dat.old时，update_file只是创建了另一个example.dat，并且似乎一直满足混沌稳态假设。

一种解决方案是：将update_file设置为在明显更长的时间后运行。就我而言，时间。睡眠(60(起作用了！

来自chaos run experiment.json的日志

[2021-12-07 01:11:19 INFO] Validating the experiment's syntax
[2021-12-07 01:11:19 INFO] Experiment looks valid
[2021-12-07 01:11:19 INFO] Running experiment: Does our service tolerate the loss of its example file?     
[2021-12-07 01:11:19 INFO] Steady-state strategy: default
[2021-12-07 01:11:19 INFO] Rollbacks strategy: default
[2021-12-07 01:11:19 INFO] Steady state hypothesis: The exchange file must exist
[2021-12-07 01:11:19 INFO] Probe: service-is-unavailable
[2021-12-07 01:11:21 INFO] Steady state hypothesis is met!
[2021-12-07 01:11:21 INFO] Playing your experiment's method now...
[2021-12-07 01:11:21 INFO] Action: move-example-file
[2021-12-07 01:11:21 INFO] Steady state hypothesis: The exchange file must exist
[2021-12-07 01:11:21 INFO] Probe: service-is-unavailable
[2021-12-07 01:11:23 CRITICAL] Steady state probe 'service-is-unavailable' is not in the given tolerance so failing this experiment
[2021-12-07 01:11:23 INFO] Experiment ended with status: deviated
[2021-12-07 01:11:23 INFO] The steady-state has deviated, a weakness may have been discovered