Redis 错误 8 连接本地主机：6379。 提供了节点名或服务名，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（大约 2000 个）使用相同的 redis 实例来写入数据，但有些线程会抛出以下异常：

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.

有没有办法解决这个问题？
当这个异常发生时，我尝试连接到redis服务器并使用ulimit -n设置一个更大的数字，但是这两种方法都不起作用。

Answer 1

我知道为什么会这样。 它是由 redis-server 的最大连接数引起的，它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。

Answer 2

我也遇到过这个问题。

当您使用错误的 Redis HOST 时，您也会遇到该错误。

Answer 3

很可能 reds 服务器没有运行。 使用“redis-server”命令运行它。

brew services start redis (on mac)