无法使用 DataStax Python 驱动程序远程连接到 Cassandra [英] Unable to connect to Cassandra remotely using DataStax Python driver

问题描述

我无法远程(从我的笔记本电脑)连接到 Cassandra(在 EC2 节点上运行).当我为 Cassandra 使用 DataStax Python 驱动程序时:

I'm having trouble connecting to Cassandra (running on an EC2 node) remotely (from my laptop). When I use the DataStax Python driver for Cassandra:

from cassandra.cluster import Cluster
cluster = Cluster(['10.X.X.X'], port=9042)
cluster.connect()

我明白了:

Traceback (most recent call last):
  File "/Users/user/virtualenvs/test/lib/python2.7/site-packages/IPython/core/interactiveshell.py", line 3035, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-23-dc85f20fd4f5>", line 1, in <module>
    session = cluster.connect()
  File "/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py", line 755, in connect
    self.control_connection.connect()
  File "/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py", line 1868, in connect
    self._set_new_connection(self._reconnect_internal())
  File "/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py", line 1903, in _reconnect_internal
    raise NoHostAvailable("Unable to connect to any servers", errors)
NoHostAvailable: ('Unable to connect to any servers', {'10.X.X.X': OperationTimedOut('errors=None, last_host=None',)})

但是 Cassandra 正在运行，因为 nodetool status 给了我:

But Cassandra is running because nodetool status gives me:

UN 127.0.0.1 124.18 KB 256 100.0% 4d973e17-ae08-3aa1-81d2-605b92753694 rack1

Cassandra 似乎也在监听 9042 端口:

Cassandra also seems to be listening on port 9042:

netstat -nltp | grep 9042

tcp6       0      0 0.0.0.0:9042            :::*                    LISTEN      -

而且我可以从我的笔记本电脑 telnet 到 Cassandra:

And I can telnet from my laptop to Cassandra:

$ telnet 10.X.X.X 9042
Trying 10.X.X.X...
Connected to ip-10-X-X-X.
Escape character is '^]'.

来自我的 cassandra.yaml 的相关亮点:

Relevant highlights from my cassandra.yaml:

start_native_transport: true
rpc_address: 0.0.0.0
rpc_port: 9160
broadcast_rpc_address: 10.X.X.X

/var/log/cassandra/system.log 显示没有任何用处.

编辑:我还可以使用服务器上的 cqlsh 127.0.0.1 9042 和笔记本电脑上的 cqlsh 10.X.X.X 9042 连接到 Cassandra，没有任何问题.

edit: I can also connect to Cassandra using cqlsh 127.0.0.1 9042 on the server, and cqlsh 10.X.X.X 9042 from my laptop without any problems.

解决方案

由于某种原因，看起来我测试脚本的地方(PyCharm 中的 Python 控制台)是我的脚本唯一无法运行的地方.在 PyCharm 或 Python/iPython 交互模式下作为脚本运行没有问题.我会留下这个问题，因为它包含一个相当完整的 Python 到 Cassandra 连接故障排除清单.

Looks like the one place where I tested my script (a Python console inside PyCharm) is, for some reason, the only place where my script does not work. No problems running as a script in PyCharm or in Python/iPython interactive mode. I will leave the question, as it contains a fairly complete checklist for Python-to-Cassandra connection troubleshooting.

推荐答案

如果 控制连接超时 已超过.尝试增加它或将其设置为 None 以完全禁用此超时.例如:

Such exception can be thrown if a control connection timeout was exceeded. Try to increase it or set it to None to completely disable this timeout. For example:

from cassandra.cluster import Cluster
cluster = Cluster(['127.0.0.1'], control_connection_timeout=10,  port=9042)
cluster.connect()

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