CqlEngine - sync_table（）KeyError：'cqlengine'

Question

I am just starting to work with Cassandra in python using cqlengine.

I tried following this link and tried ran this script:

from cqlengine import columns
from cqlengine import Model
from cqlengine import connection

from cqlengine.management import sync_table

import uuid


class ExampleModel(Model):
    example_id = columns.UUID(primary_key=True, default=uuid.uuid4)
    example_type = columns.Integer(index=True)
    created_at = columns.DateTime()
    description = columns.Text(required=False)


connection.setup(['127.0.0.1'], 'cqlengine')

sync_table(ExampleModel)

But it throws up this error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/zopper/Desktop/django-cassandra/local/lib/python2.7/site-packages/cqlengine/management.py", line 92, in sync_table
    keyspace = cluster.metadata.keyspaces[ks_name]
KeyError: 'cqlengine'

My pip freeze is:

Django==1.7.3
argparse==1.2.1
blist==1.3.6
cassandra-driver==2.1.3
cqlengine==0.21.0
django-cassandra-engine==0.2.1
djangotoolbox==1.6.2
futures==2.2.0
six==1.9.0
wsgiref==0.1.2

Please help me understand and solve this issue. Thanks.

Answer 1

This was overlooked on my end - I'm fixing it now. create_missing_keyspace would rarely "do the right thing", and it's very difficult and time consuming to fix a keyspace created with the wrong parameters. You must now explicitly create a keyspace with the parameters you want.

Answer 2

Edit : The create_missing_keyspace is ignored in cqlengine 0.21, but not 0.20. Try a version < 0.21 of cqlengine or manual creation (see below).

Create a keyspace like this :

cqlengine.management.create_keyspace("cqlengine", replication_factor=1, strategy_class="SimpleStrategy")

The available strategies are SimpleStrategy and NetworkTopologyStrategy .

I couldn't find updated docs for 0.21 so I checked the source . Here's the declaration of create_keyspace in 0.21:

def create_keyspace(name, strategy_class, replication_factor, durable_writes=True, **replication_values):
    """
    creates a keyspace
    :param name: name of keyspace to create
    :param strategy_class: keyspace replication strategy class
    :param replication_factor: keyspace replication factor
    :param durable_writes: 1.2 only, write log is bypassed if set to False
    :param **replication_values: 1.2 only, additional values to ad to the replication data map
    """