Can be one of the following: – database (default) Use a relational database supported by the Django ORM. – cache Use memcached to store the results. – mongodb Use MongoDB to store the results. – redis receive the result once. See Executing Tasks). 3.4 Database backend settings Please see the Django ORM database settings documentation: http://docs.djangoproject.com/en/dev/ref/settings/#database- engine all of the features without using Django. 6.2.3 Why is Django a dependency? Celery uses the Django ORM for database access when using the database result backend, the Django cache framework when using the

Can be one of the following: database (default) Use a relational database supported by the Django ORM. cache Use memcached [http://memcached.org] to store the results. mongodb Use MongoDB [http://mongodb only receive the result once. See Executing Tasks). Database backend settings Please see the Django ORM database settings documentation: http://docs.djangoproject.com/en/dev/ref/settings/#database-engine use all of the features without using Django. Why is Django a dependency? Celery uses the Django ORM for database access when using the database result backend, the Django cache framework when using the

thread (multithreaded) solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch, Riak MongoDB, CouchDB, Couchbase, ArangoDB Amazon DynamoDB, Amazon backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, MongoDB [http://www.mongodb.org], Memcached [http://memcached.org], Redis [https://redis.io/], RPC can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

thread (multithreaded) solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch, Riak MongoDB, CouchDB, Couchbase, ArangoDB Amazon DynamoDB, Amazon backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, MongoDB [http://www.mongodb.org], Memcached [http://memcached.org], Redis [https://redis.io/], RPC can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

thread (multithreaded) solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch, Riak MongoDB, CouchDB, Couchbase, ArangoDB Amazon DynamoDB, Amazon backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, MongoDB [http://www.mongodb.org], Memcached [http://memcached.org], Redis [https://redis.io/], RPC can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

thread (multithreaded) solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch, Riak MongoDB, CouchDB, Couchbase, ArangoDB Amazon DynamoDB, Amazon backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, MongoDB [http://www.mongodb.org], Memcached [http://memcached.org], Redis [https://redis.io/], RPC can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

Redis 2.2. Getting Started 7 Celery Documentation, Release 4.0.0 • Memcached, • SQLAlchemy, Django ORM • Apache Cassandra, Elasticsearch • Serialization • pickle, json, yaml, msgpack. • zlib, bzip2 compression the states somewhere. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, Redis, RPC (RabbitMQ/AMQP), and – or you can define your own. 2.2. Getting Started 21 can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. 56 Chapter 2. Contents Celery

Eventlet, gevent solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch Serialization pickle, json, yaml, msgpack. zlib, bzip2 compression backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, Memcached [http://memcached.org], Redis [http://redis.io/], RPC (RabbitMQ [http://www.rabbitmq.com/]/AMQP) be retrieved later. There are several built- in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

Eventlet, gevent solo (single threaded) Result Stores AMQP, Redis Memcached, SQLAlchemy, Django ORM Apache Cassandra, Elasticsearch Serialization pickle, json, yaml, msgpack. zlib, bzip2 compression backends to choose from: SQLAlchemy [http://www.sqlalchemy.org/]/Django [http://djangoproject.com] ORM, Memcached [http://memcached.org], Redis [http://redis.io/], RPC (RabbitMQ [http://www.rabbitmq.com/]/AMQP) be retrieved later. There are several built- in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for

Eventlet, gevent • solo (single threaded) • Result Stores • AMQP, Redis • Memcached, • SQLAlchemy, Django ORM • Apache Cassandra, Elasticsearch • Serialization • pickle, json, yaml, msgpack. • zlib, bzip2 compression the states somewhere. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, Redis, RPC (RabbitMQ/AMQP), and – or you can define your own. For this example we use can be retrieved later. There are several built-in result backends to choose from: SQLAlchemy/Django ORM, Memcached, RabbitMQ/QPid (rpc), and Redis – or you can define your own. No backend works well for