503 Service Unavailable

curl -s -o page.html -D headers.txt -x http://USER:[email protected]:8000 \
     -w 'CONNECT %{http_connect} / site %{http_code}\n' https://example.com/

grep -iE '^(retry-after|server)' headers.txt
grep -ioE 'maintenance|checking your browser|captcha' page.html | sort -u

import requests

URL = "https://example.com/"
PROXY = "http://USER:[email protected]:8000"

via_proxy = requests.get(URL, proxies={"http": PROXY, "https": PROXY}, timeout=30)
direct = requests.get(URL, timeout=30)

print("proxy:", via_proxy.status_code, "direct:", direct.status_code)
if via_proxy.status_code == 503:
    print("retry-after:", via_proxy.headers.get("Retry-After"))
    print("server:", via_proxy.headers.get("Server"))
    print(via_proxy.text[:300])

# settings.py
RETRY_HTTP_CODES = [500, 502, 503, 504]
RETRY_TIMES = 2


# in the spider
handle_httpstatus_list = [503]

def parse(self, response):
    if response.status == 503:
        self.logger.warning(
            "503 at %s, retry-after=%s", response.url, response.headers.get("Retry-After")
        )
        return

from playwright.sync_api import Error, sync_playwright

PROXY = {"server": "http://resi.proxymonkey.io:8000", "username": "USER", "password": "PASS"}

with sync_playwright() as p:
    browser = p.chromium.launch(proxy=PROXY)
    page = browser.new_page()
    response = page.goto("https://example.com/")
    if response.status == 503:
        print(response.headers.get("retry-after"), "|", page.title())
        page.screenshot(path="503.png")
    browser.close()

import { fetch, ProxyAgent } from "undici";

const dispatcher = new ProxyAgent("http://USER:[email protected]:8000");

const res = await fetch("https://example.com/", { dispatcher });

if (res.status === 503) {
  console.log("retry-after:", res.headers.get("retry-after"));
  console.log("server:", res.headers.get("server"));
  console.log((await res.text()).slice(0, 300));
}