cassandra.cluster.NoHostAvailable "Unable to connect to any servers" for cassandra-driver database

Question

当我使用此命令时：

session = cluster.connect('demo')

。它给了我一个错误说：

>>> session = cluster.connect()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "cassandra/cluster.py", line 1152, in cassandra.cluster.Cluster.connect (cassandra/cluster.c:17598)
  File "cassandra/cluster.py", line 1185, in cassandra.cluster.Cluster.connect (cassandra/cluster.c:17419)
  File "cassandra/cluster.py", line 1172, in cassandra.cluster.Cluster.connect (cassandra/cluster.c:17122)
  File "cassandra/cluster.py", line 2618, in cassandra.cluster.ControlConnection.connect (cassandra/cluster.c:47646)
  File "cassandra/cluster.py", line 2655, in cassandra.cluster.ControlConnection._reconnect_internal (cassandra/cluster.c:48543)
cassandra.cluster.NoHostAvailable: ('Unable to connect to any servers', {'127.0.0.1': ConnectionRefusedError(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})

我在Fedora上。

Answer 1

以下是使用 DataStaX python 驱动程序(cassandra-driver(连接到 Cassandra 实例的标准过程。

from cassandra.cluster import Cluster
from cassandra.policies import DCAwareRoundRobinPolicy
from cassandra.auth import PlainTextAuthProvider
def cassandra_conn():
   auth_provider = PlainTextAuthProvider(username='cassandra', password='password')
   cluster = Cluster(['127.0.0.1'], load_balancing_policy=DCAwareRoundRobinPolicy(local_dc='US-WEST'), port=9042, auth_provider=auth_provider)
   session = cluster.connect()
   return session, cluster

注意：我已包含基于本地 cassandra 集群的连接凭据。但是，当连接到其他实例时，这些凭据会有所不同。