ECONNRESET and socket hang up

# one retry after a reset, on a new connection
curl -s -o /dev/null -x http://USER:[email protected]:8000 --retry 1 --retry-all-errors --retry-delay 2 \
     -w '%{http_code} after %{num_connects} new connection(s)\n' https://example.com/

# curl: (56) Recv failure: Connection reset by peer

import requests
from requests.adapters import HTTPAdapter
from urllib3.util import Retry

PROXY = "http://USER:[email protected]:8000"
retry = Retry(total=2, connect=1, read=1, backoff_factor=1, allowed_methods={"GET", "HEAD"})

with requests.Session() as http:
    http.mount("https://", HTTPAdapter(max_retries=retry))
    http.mount("http://", HTTPAdapter(max_retries=retry))
    try:
        r = http.get("https://example.com/", proxies={"http": PROXY, "https": PROXY}, timeout=(10, 30))
        print(r.status_code)
    except requests.exceptions.ConnectionError as err:
        print(err)

# ('Connection aborted.', ConnectionResetError(104, 'Connection reset by peer'))

# settings.py: dropped connections are on Scrapy's default retry list
RETRY_TIMES = 2
DOWNLOAD_TIMEOUT = 60


# in the spider
from scrapy.exceptions import DownloadFailedError, ResponseDataLossError
from twisted.internet.error import ConnectionLost

async def start(self):
    for url in self.start_urls:
        yield scrapy.Request(url, errback=self.on_error)

def on_error(self, failure):
    if failure.check(ConnectionLost, DownloadFailedError, ResponseDataLossError):
        self.logger.warning("connection dropped after retries: %s", failure.request.url)

import time

from playwright.sync_api import Error, sync_playwright

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


def load(page, url, attempts=2):
    for attempt in range(1, attempts + 1):
        try:
            return page.goto(url, wait_until="domcontentloaded")
        except Error as err:
            dropped = "ERR_CONNECTION_RESET" in err.message or "ERR_EMPTY_RESPONSE" in err.message
            if not dropped or attempt == attempts:
                raise
            time.sleep(2 * attempt)


with sync_playwright() as p:
    browser = p.chromium.launch(proxy=PROXY)
    page = browser.new_page()
    print(load(page, "https://example.com/").status)
    browser.close()

import { fetch, ProxyAgent } from "undici";

const newDispatcher = () => new ProxyAgent({ uri: "http://USER:[email protected]:8000", keepAliveTimeout: 2_000 });
let dispatcher = newDispatcher();

const DROPPED = new Set(["ECONNRESET", "UND_ERR_SOCKET"]);
const codeOf = (err) => {
  for (let e = err; e; e = e.cause) if (typeof e.code === "string") return e.code;
  return "";
};

async function get(url, attempts = 2) {
  for (let i = 1; ; i++) {
    try {
      return await fetch(url, { dispatcher, signal: AbortSignal.timeout(30_000) });
    } catch (err) {
      if (!DROPPED.has(codeOf(err)) || i === attempts) throw err;
      await dispatcher.close();
      dispatcher = newDispatcher();
      await new Promise((resolve) => setTimeout(resolve, 1_000 * i));
    }
  }
}

console.log((await get("https://example.com/")).status);