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

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

 从cassandra.cluster导入集群
 cluster = 10.XXX']，port = 9042）
 cluster.connect（）
  

get：

 跟踪（最近一次调用）：
文件/ Users / user / virtualenvs / test / lib /python2.7/site-packages/IPython/core/interactiveshell.py，第3035行，在run_code 
 exec（code_obj，self.user_global_ns，self.user_ns）
文件< ipython输入-23-dc85f20fd4f5，行1，in< module> 
 session = cluster.connect（）
文件/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py，行755，在connect 
 self.control_connection.connect（）
文件/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py，行1868，在连接
 self._set_new_connection（self._reconnect_internal（））
文件/Users/user/virtualenvs/test/lib/python2.7/site-packages/cassandra/cluster.py，行号1903，在_reconnect_internal 
 raise NoHostAvailable（无法连接到任何服务器，错误）
 NoHostAvailable：（'无法连接到任何服务器'，{'10 .XXX'：OperationTimedOut（'errors = None，last_host = None' ，）}）
  

但是Cassandra正在运行，因为 nodetool status 给我：

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

Cassandra似乎也在9042号港口上侦听：

  netstat -nltp | grep 9042 
 
 tcp6 0 0 0.0.0.0:9042 ::: * LISTEN  -  
  

我可以从笔记本电脑到Cassandra：

  $ telnet 10.XXX 9042 
尝试10。 XXX .. 
已连接到ip-10-XXX。 
转义字符是'^]'。 
  

我的cassandra.yaml相关亮点：

  start_native_transport：true 
 rpc_address：0.0.0.0 
 rpc_port：9160 
 broadcast_rpc_address：10.XXX 
  
 
 
 
  /var/log/cassandra/system.log 显示没有用。
 
 
 
 编辑：
我也可以使用 cqlsh 127.0.0.1 9042 连接到Cassandra服务器和 cqlsh 10.XXX 9042 从我的笔记本电脑没有任何问题。
 
 
 
  >：
解决。看起来像一个地方，我测试我的脚本（PyCharm中的Python控制台）是，由于某种原因，唯一的地方，我的脚本不工作。在PyCharm或Python / iPython交互模式下作为脚本运行时没有问题。我会离开这个问题，因为它包含一个相当完整的清单，用于Python-to-Cassandra连接疑难解答。
解决方案
简单的调试方法为：
在另一台安装了cassandra的机器上，使用cassandra cli命令cqlsh 10.XXX连接远程cassandra服务器。如果失败，那么您应该修改cassandra远程模式的cassandra配置文件。
 
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()
I get:
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',)})
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 also seems to be listening on port 9042:
netstat -nltp | grep 9042

tcp6       0      0 0.0.0.0:9042            :::*                    LISTEN      -
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 '^]'.
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 shows nothing useful.

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.

edit:
Solved. 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.
解决方案
Here is a simple debug method for you: 
 On another machine which has cassandra installed, using cassandra cli command "cqlsh 10.X.X.X" to connect the remote cassandra server. If failed , then you should modify cassandra configuration file for the cassandra remote mode.

                        
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