Socket error: Address already in use

Question

我有一个经常运行启动服务器的 CherryPy 脚本。今天我不得不启动和停止它几次以修复配置文件中的一些错误，我猜套接字并没有完全关闭，因为当我再次尝试启动它时我遇到了这个问题：

[23/Mar/2015:14:08:00] ENGINE Listening for SIGHUP.
[23/Mar/2015:14:08:00] ENGINE Listening for SIGTERM.
[23/Mar/2015:14:08:00] ENGINE Listening for SIGUSR1.
[23/Mar/2015:14:08:00] ENGINE Bus STARTING
CherryPy Checker:
The Application mounted at '' has an empty config.

[23/Mar/2015:14:08:00] ENGINE Started monitor thread 'Autoreloader'.
[23/Mar/2015:14:08:00] ENGINE Started monitor thread '_TimeoutMonitor'.
[23/Mar/2015:14:08:00] ENGINE Error in HTTP server: shutting down
Traceback (most recent call last):
  File "/home/andrew/virtualenvs/mikernels/lib/python2.7/site-packages/cherrypy/process/servers.py", line 188, in _start_http_thread
    self.httpserver.start()
  File "/home/andrew/virtualenvs/mikernels/lib/python2.7/site-packages/cherrypy/wsgiserver/wsgiserver2.py", line 1848, in start
    raise socket.error(msg)
error: No socket could be created

我编辑了 CherryPy 的 wsgiserver2.py 以查看 socket.error 和 error.strerror 的详细信息

98  (98, 'Address already in use') Address already in use

同时我的套接字构造为：

af = 2
socktype = 1
proto = 6
canonname = ''
sa = ('0.0.0.0', 2112)
self.bind(af, socktype, proto)

（这不是确切的代码，但这是触发错误时的值）

我检查了 netstat 并没有看到任何在端口 2112 上侦听的东西，可能是什么导致了问题，我该如何诊断它？

谢谢！

Answer 1

您可以尝试以下方法

from socket import *

sock=socket()
sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
# then bind

来自文档：

The SO_REUSEADDR flag tells the kernel to reuse a local socket in TIME_WAIT state, without waiting for its natural timeout to expire.

完整的解释如下：

Running an example several times with too small delay between executions, could lead to this error:

socket.error: [Errno 98] Address already in use

This is because the previous execution has left the socket in a TIME_WAIT state, and can’t be immediately reused.

There is a socket flag to set, in order to prevent this, socket.SO_REUSEADDR:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((HOST, PORT))

Answer 2

您可以通过以下操作找到进程并kill它：

ps aux | grep python

，查找进程 ID，并通过执行以下操作手动停止它：

sudo kill -9 PID

用您的 PID 替换 PID。

在使用 Flask/CherryPy 进行测试时，我经常不得不这样做。有兴趣看看是否有更简单的方法（例如首先防止它）

Answer 3

通过以下方式更容易做到：

检查 PID(:5000 是主机，因为我在 127.0.0.1:5000 运行):
$ lsof -i :5000
然后杀掉它:
$ sudo kill -9 PID

Socket error: Address already in use

Socket error: Address already in use

python

sockets

cherrypy