客户端

Question

我正在尝试在Python中实现Reactor pattern。我认为我使用multiprocessing和select.select开始相当不错。但是，我正在尝试对我的服务器进行压力测试，因此我编写了一个简单的DoS客户端来充满连接。但是我得到了一个有趣的错误：

[WinError 10061]无法建立连接，因为目标计算机主动拒绝它

有趣的是，我正在为服务器上的backlog amount做socket.listen(5)。在我从select.select准备读者之后，我显示了计数，我只有1或2 - 而不是我期望的5。

对于少量线程（~20）我没有注意到它的阻塞，但是对于更大的数字（50+），它确实倾向于拒绝连接。

我的服务器或客户端问题（或仅在OS /套接字级别）？这是我可以解决的问题吗？如果是这样，怎么样？

这是我的代码：

客户端

import threading
import time
import socket
from contextlib import contextmanager

IP = '127.0.0.1'
PORT = 4200

@contextmanager
def open_socket(ip, port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try:
        sock.connect((ip, port))
        yield sock
    finally:
        sock.close()


class Flood(threading.Thread):
    def __init__(self, id):
        super(Flood, self).__init__()
        self.id = id
        self.failed = False


    def run(self):
        try:
            with open_socket(IP, PORT) as sock:
                msg = "Hello this is some data from %d" % self.id
                sock.send(msg.encode())
        except Exception as e:
            print(e)
            self.failed = True


def make_threads(count):
    return [Flood(_) for _ in range(count)]


threads = make_threads(5000)

start = time.time()
for t in threads:
    t.start()

for t in threads:
    t.join()

print("Failed: ", sum(1 if x.failed else 0 for x in threads))
print("Done in %f seconds" % (time.time() - start))

服务器

import sys
import logging
import socket
import select
import time
import queue
from multiprocessing import Process, Queue, Value
log = logging.getLogger(__name__)
log.setLevel(logging.DEBUG)
log.addHandler(logging.StreamHandler())

IP = '127.0.0.1'
PORT = 4200

keep_running = True

def dispatcher(q, keeprunning):
    try:
        while keeprunning:
            val = None
            try:
                val = q.get(True, 5)
                if val:
                    log.debug(val[0].recv(1024).decode())
                    val[0].shutdown(socket.SHUT_RDWR)
                    val[0].close()
            except queue.Empty:
                pass
        log.debug("Dispatcher quitting")
    except KeyboardInterrupt:
        log.debug("^C caught, dispatcher quitting")


def mainloop(sock):
    readers, writers, errors = [sock], [], []
    timeout = 5
    while True:
        readers, writers, errors = select.select(readers,
                                                 writers,
                                                 errors,
                                                 timeout)
        incoming = yield readers, writers, errors
        if incoming and len(incoming) == 3:
            readers, writers, errors = incoming
        if not readers:
            readers.append(sock)


def run_server():
    keeprunning = Value('b', True)
    q = Queue()
    p = Process(target=dispatcher, args=(q, keep_running))
    try:
        p.start()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        sock.bind((IP, PORT))
        sock.listen(50)
        sock.setblocking(0)
        loop = mainloop(sock)
        for readers, writers, errors in loop:
            if readers:
                client, addr = readers[0].accept()
                q.put((client, addr))
            log.debug('*'*50)
            log.debug('%d Readers', len(readers))
            log.debug('%d Writers', len(writers))
            log.debug('%d Errors', len(errors))


    except KeyboardInterrupt:
        log.info("^C caught, shutting down...")
    finally:
        keeprunning.value = False
        sock.close()
        p.join()

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: test.py (client|server)")
    elif sys.argv[1] == 'client':
        run_client()
    elif sys.argv[1] == 'server':
        run_server()

Answer 1

我尝试测试您的代码，但在import queue上失败了。

然而，可能是那个

您的操作系统在指定listen()函数时起作用：“实现可能会对积压施加限制并以静默方式减少指定值。”
如果有足够的不完整连接，您的操作系统将停止接受连接，这可能不会在请求时显示。

这些只是关于可能是什么原因的猜测;也许我完全错了。

如何允许更多同时套接字连接？

客户端

服务器

1 个答案: