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========================
Third party integrations
========================
Celery
------
Here's how, in substance, CQLengine can be plugged to `Celery
<http://celery.readthedocs.org/>`_:
.. code-block:: python
from celery import Celery
from celery.signals import worker_process_init, beat_init
from cassandra.cqlengine import connection
from cassandra.cqlengine.connection import (
cluster as cql_cluster, session as cql_session)
def cassandra_init(**kwargs):
""" Initialize a clean Cassandra connection. """
if cql_cluster is not None:
cql_cluster.shutdown()
if cql_session is not None:
cql_session.shutdown()
connection.setup()
# Initialize worker context for both standard and periodic tasks.
worker_process_init.connect(cassandra_init)
beat_init.connect(cassandra_init)
app = Celery()
uWSGI
-----
This is the code required for proper connection handling of CQLengine for a
`uWSGI <https://uwsgi-docs.readthedocs.org>`_-run application:
.. code-block:: python
from cassandra.cqlengine import connection
from cassandra.cqlengine.connection import (
cluster as cql_cluster, session as cql_session)
try:
from uwsgidecorators import postfork
except ImportError:
# We're not in a uWSGI context, no need to hook Cassandra session
# initialization to the postfork event.
pass
else:
@postfork
def cassandra_init(**kwargs):
""" Initialize a new Cassandra session in the context.
Ensures that a new session is returned for every new request.
"""
if cql_cluster is not None:
cql_cluster.shutdown()
if cql_session is not None:
cql_session.shutdown()
connection.setup()
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