Redis 连接 localhost 时出现错误 8：6379。提供节点名或服务名，或未知

Question

我的环境是Mac OS 10.9.2，python3.3，redis-2.6.9（64位）。

我有很多线程（近2000个）使用同一个redis实例来写入数据，但是有些线程抛出以下异常：

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.3/site-packages/redis/connection.py", line 250, in connect
    sock = self._connect()
  File "/usr/local/lib/python3.3/site-packages/redis/connection.py", line 268, in _connect
    self.socket_timeout)
  File "/usr/local/Cellar/python3/3.3.4/Frameworks/Python.framework/Versions/3.3/lib/python3.3/socket.py", line 417, in create_connecti
on
    for res in getaddrinfo(host, port, 0, SOCK_STREAM):
socket.gaierror: [Errno 8] nodename nor servname provided, or not known

Traceback (most recent call last):
  File "/usr/local/Cellar/python3/3.3.4/Frameworks/Python.framework/Versions/3.3/lib/python3.3/threading.py", line 901, in _bootstrap_i
nner
    self.run()
  File "/usr/local/Cellar/python3/3.3.4/Frameworks/Python.framework/Versions/3.3/lib/python3.3/threading.py", line 858, in run
    self._target(*self._args, **self._kwargs)
  File "proxypool.py", line 289, in _efficiency_proxy
    self.rdb.zadd(db_proxy, time_delay, proxy)
  File "/usr/local/lib/python3.3/site-packages/redis/client.py", line 1345, in zadd
    return self.execute_command('ZADD', name, *pieces)
  File "/usr/local/lib/python3.3/site-packages/redis/client.py", line 464, in execute_command
    connection.send_command(*args)
  File "/usr/local/lib/python3.3/site-packages/redis/connection.py", line 334, in send_command
    self.send_packed_command(self.pack_command(*args))
  File "/usr/local/lib/python3.3/site-packages/redis/connection.py", line 316, in send_packed_command
    self.connect()
  File "/usr/local/lib/python3.3/site-packages/redis/connection.py", line 253, in connect
    raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error 8 connecting localhost:6379. nodename nor servname provided, or not known.

有什么办法可以解决这个问题吗？
我尝试在发生此异常时连接到redis服务器并使用ulimit -n设置更大的数字，但这两种方法都不起作用。

Answer 1

我知道为什么会这样。这是由 redis-server 的最大连接数引起的，并且与操作系统设置的最大文件处理程序数有关。
如果我设置：

$ ulimit -n 1024

有用。