python3写一个http接口服务(url, get, post)，接口限流、拒绝访问
http(url)接口限流/拒绝访问/限制队列
接口限流(rate-limit)，笔者最近工作中，遇到提供给客户的算法微服务，遇到大量请求挂掉了，除了扩容负载均衡外，也采取了限流的方式。
一般来说，常见的接口限流，我们可以采用
- a. （看门和安保）WEB服务器/反向代理服务器(c语言), Nginx/Apache等支持 高并发负载均衡、拦截静态请求、SSL支持、保留80端口;
- b. （运行和管理）WEB服务器(wsgi, http, python), Gunicorn/uWsgi等支持 多进程多线程、失败重启、接收请求分发(调用服务);
- c. （工作和业务）WEB服务框架(轻量级、python), Fastapi/flask/Tornado等支持 后端应用、单个服务、轻量级并发;
一般架构
(nginx) -> (gunicorn) -> fastapi
限流方式
- a. Nginx配置限流, 其内置漏桶算法、令牌桶算法, 可配置 limit_req_zone/limit_req/limit_rate(burst, nodelay)等模块限流;
- b. Gunicorn配置限流, 其内置计数器, 可配置队列queue长度等拒绝访问, 可采用gunicorn-proxy请求缓冲、分流;
- c. FastAPI配置限流, 可配置计数器(内存缓存)、信号量(redis缓存)等, 计数(时间、IP)限制访问;
fastapi + slowapi 限流
# !/usr/bin/python
# -*- coding: utf-8 -*-
# @time : 2023/02/01 21:07
# @author : Mo
# @function: 限流(slowapi), http of fastapi
import time
from fastapi import FastAPI, Request, Response, File, UploadFile
from starlette.responses import JSONResponse
from pydantic import BaseModel
from slowapi.errors import RateLimitExceeded
from slowapi.util import get_remote_address
from slowapi import Limiter
def _rate_limit_exceeded_handler(request: Request, exc: RateLimitExceeded) -> Response:
"""
Build a simple JSON response that includes the details of the rate limit
that was hit. If no limit is hit, the countdown is added to headers.
"""
response = JSONResponse({"error": f"Rate limit exceeded: {exc.detail}; status_code: {ERROR_CODE}; "
f"request: {request.base_url}"}, status_code=ERROR_CODE)
response = request.app.state.limiter._inject_headers(response, request.state.view_rate_limit)
return response
LIMIT = "{}/second".format(5*2) # ("5/day") ("5/hour") (5/minute) ("5/second") # 需放在@app.后
ERROR_CODE = 429
limiter = Limiter(key_func=get_remote_address)
app = FastAPI()
app.state.limiter = limiter
app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
class Item(BaseModel):
a: int = None
b: int = None
@app.post("/calculate")
@limiter.limit(LIMIT) # ("5/day") ("5/hour") (5/minute) ("5/second") # 需放在@app.后
async def calculate(item: Item, request: Request): # Request必须配置
a = item.a
b = item.b
c = a + b
res = {"code": 200, "res": c}
time.sleep(0.05)
return res
if __name__ == '__main__':
import uvicorn
uvicorn.run(app=app,
host="0.0.0.0",
port=8832,
workers=1)
测试
# !/usr/bin/python
# -*- coding: utf-8 -*-
# @time : 2020/7/9 14:14
# @author : Mo
# @function: test
import requests, time, json, threading, random
import pandas as pd
def get_variable_name():
""" 获取 string 变量的变量名字, variable_name: str """
import inspect
variable_name_dict = dict(inspect.currentframe().f_locals.items())
res = None
for k, v in variable_name_dict.items():
if "frame" in str(type(v)):
res = k
break
return res
class PressTet(object):
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36',
'Content-Type': 'application/json; charset=UTF-8',
'Connection': 'close',
}
def __init__(self, press_url, data_json):
self.press_url = press_url
self.session = requests.Session()
self.session.headers = self.headers
self.data_json = data_json
def work(self):
'''压测接口'''
time_str = str(time.time()) + str(random.random())
self.data_json["time"] = time_str # 加个参数使得每次传参不一样
global ERROR_NUM
try:
html = self.session.post(self.press_url, data=json.dumps(self.data_json))
html_json = html.json()
# 错误判断
if html_json.get("code", 0) != 200:
print(html.json())
ERROR_NUM += 1
html.close()
except Exception as e:
print(str(e))
ERROR_NUM += 1
def tet_onework(self):
'''一次并发处理单个任务'''
i = 0
while i < ONE_WORKER_NUM:
i += 1
self.work()
time.sleep(LOOP_SLEEP)
def run(self):
'''使用多线程进程并发测试'''
t1 = time.time()
Threads = []
for i in range(THREAD_NUM):
t = threading.Thread(target=self.tet_onework, name="T" + str(i))
t.setDaemon(True)
Threads.append(t)
for t in Threads:
t.start()
for t in Threads:
t.join()
t2 = time.time()
print("===============压测结果===================")
print("URL:", self.press_url)
print("任务数量:", THREAD_NUM, "*", ONE_WORKER_NUM, "=", THREAD_NUM * ONE_WORKER_NUM)
print("总耗时(秒):", t2 - t1)
print("每次请求耗时(秒):", (t2 - t1) / (THREAD_NUM * ONE_WORKER_NUM))
print("每秒承载请求数:", 1 / ((t2 - t1) / (THREAD_NUM * ONE_WORKER_NUM)))
print("错误数量:", ERROR_NUM)
if __name__ == '__main__':
# 在work里边设置一下错误判断, work
press_url = 'http://localhost:8832/calculate'
data_sample = {"a": 12, "b": 32}
THREAD_NUM = 50 # 并发线程总数, 可设置 10, 20, 30, 50...
ONE_WORKER_NUM = 10 # 每个线程的循环次数, 可设置 10, 20, 30, 50...
LOOP_SLEEP = 0.01 # 每次请求时间间隔(秒), 可设置 0.1, 0.01, 0.001, 0.0001
ERROR_NUM = 0 # 出错数
obj = PressTet(press_url=press_url, data_json=data_sample)
obj.run()
"""
===============压测结果===================
URL: http://localhost:8832/calculate
任务数量: 50 * 10 = 500
总耗时(秒): 21.13799810409546
每次请求耗时(秒): 0.04227599620819092
每秒承载请求数: 23.654084816249732
错误数量: 400
tcp 默认有心跳确保长连接，http1.1 无限制，nginx 默认一分半，gunicorn 默认 1 分钟，uvicorn 和 starlette 默认无限制，
所以要确保连接需要修改 nginx 和 gunicorn 的默认设置，另外浏览器也有限制但是比较长。
"""