为什么我会看到“对等连接重置"错误? [英] Why am I seeing 'connection reset by peer' error?
问题描述
我正在使用python 2.6.1在Mac OS X 10.5盒子上测试 cogen .我有一个简单的回显服务器和客户端泵，它可以创建10,000个客户端连接作为测试. 1000、5000等都出色地工作.但是，在大约10,000个连接时，服务器会开始丢弃随机客户端-客户端会看到对等方重置连接".
I am testing cogen on a Mac OS X 10.5 box using python 2.6.1. I have a simple echo server and client-pumper that creates 10,000 client connections as a test. 1000, 5000, etc. all work splendidly. However at around 10,000 connections, the server starts dropping random clients - the clients see 'connection reset by peer'.
这里缺少一些基本的网络背景知识吗?
Is there some basic-networking background knowledge I'm missing here?
请注意，我的系统已配置为处理打开的文件(launchctl限制，sysctl(maxfiles等)，以及ulimit -n都有效；到此为止就可以了.另外，我已经验证了cogen正在选择在后台使用kqueue.
Note that my system is configured to handle open files (launchctl limit, sysctl (maxfiles, etc.), and ulimit -n are all valid; been there, done that). Also, I've verified that cogen is picking to use kqueue under the covers.
如果我对client-connect()调用稍加延迟，则一切正常.因此，我的问题是，当短时间内连接频率很高时，为什么承受压力的服务器会丢弃其他客户端?还有其他人碰到这个吗?
If I add a slight delay to the client-connect() calls everything works great. Thus, my question is, why would a server under stress drop other clients when there's a high frequency of connections in a short period of time? Anyone else ever run into this?
出于完整性考虑，这是我的代码.
For completeness' sake, here's my code.
这是服务器:
# echoserver.py
from cogen.core import sockets, schedulers, proactors
from cogen.core.coroutines import coroutine
import sys, socket
port = 1200
@coroutine
def server():
srv = sockets.Socket()
srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
addr = ('0.0.0.0', port)
srv.bind(addr)
srv.listen(64)
print "Listening on", addr
while 1:
conn, addr = yield srv.accept()
m.add(handler, args=(conn, addr))
client_count = 0
@coroutine
def handler(sock, addr):
global client_count
client_count += 1
print "SERVER: [connect] clients=%d" % client_count
fh = sock.makefile()
yield fh.write("WELCOME TO (modified) ECHO SERVER !\r\n")
yield fh.flush()
try:
while 1:
line = yield fh.readline(1024)
#print `line`
if line.strip() == 'exit':
yield fh.write("GOOD BYE")
yield fh.close()
raise sockets.ConnectionClosed('goodbye')
yield fh.write(line)
yield fh.flush()
except sockets.ConnectionClosed:
pass
fh.close()
sock.close()
client_count -= 1
print "SERVER: [disconnect] clients=%d" % client_count
m = schedulers.Scheduler()
m.add(server)
m.run()
这是客户:
# echoc.py
import sys, os, traceback, socket, time
from cogen.common import *
from cogen.core import sockets
port, conn_count = 1200, 10000
clients = 0
@coroutine
def client(num):
sock = sockets.Socket()
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
reader = None
try:
try:
# remove this sleep and we start to see
# 'connection reset by peer' errors
time.sleep(0.001)
yield sock.connect(("127.0.0.1", port))
except Exception:
print 'Error in client # ', num
traceback.print_exc()
return
global clients
clients += 1
print "CLIENT #=%d [connect] clients=%d" % (num,clients)
reader = sock.makefile('r')
while 1:
line = yield reader.readline(1024)
except sockets.ConnectionClosed:
pass
except:
print "CLIENT #=%d got some other error" % num
finally:
if reader: reader.close()
sock.close()
clients -= 1
print "CLIENT #=%d [disconnect] clients=%d" % (num,clients)
m = Scheduler()
for i in range(0, conn_count):
m.add(client, args=(i,))
m.run()
感谢您提供任何信息！
推荐答案
Python的套接字I/O有时会受到对等方重置连接的影响.它与全局解释器锁以及线程的调度方式有关.我博客关于该主题的一些参考文献.
Python's socket I/O sometimes suffers from connection reset by peer. It has to do with the Global Interpreter Lock and how threads are scheduled. I blogged some references on the subject.
time.sleep(0.0001)似乎是推荐的解决方案，因为它可以调整线程调度并允许套接字I/O完成.
The time.sleep(0.0001) appears to be the recommended solution because it adjusts thread scheduling and allows the socket I/O to finish.
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