DataStax Python Driver for Apache Cassandra (Beta)

A Python client driver for Apache Cassandra. This driver works exclusively with the Cassandra Query Language v3 (CQL3) and Cassandra's native protocol. As such, only Cassandra 1.2+ is supported.

Warning

This driver is currently under heavy development, so the API and layout of packages, modules, classes, and functions are subject to change. There may also be serious bugs, so usage in a production environment is not recommended at this time.

• JIRA
• Mailing List
• IRC: #datastax-drivers on irc.freenode.net (you can use freenode's web-based client)
• API Documentation

Features to be Added

• C extension for encoding/decoding messages
• Authentication/security feature support
• Twisted, gevent support
• Python 3 support
• IPv6 Support

Installation

If you would like to use the optional C extensions, please follow the instructions in the section below before installing the driver.

Installation through pip is recommended:

$ sudo pip install cassandra-driver

If you want to install manually, you can instead do:

$ sudo pip install futures scales blist # install dependencies
$ sudo python setup.py install

C Extensions

By default, two C extensions are compiled: one that adds support for token-aware routing with the Murmur3Partitioner, and one that allows you to use libev for the event loop, which improves performance.

When running setup.py, you can disable both with the --no-extensions option, or selectively disable one or the other with --no-murmur3 and --no-libev.

To compile the extenions, ensure that GCC and the Python headers are available.

On Ubuntu and Debian, this can be accomplished by running:

$ sudo apt-get install build-essential python-dev

On RedHat and RedHat-based systems like CentOS and Fedora:

$ sudo yum install gcc python-devel

On OS X, homebrew installations of Python should provide the necessary headers.

libev support

The driver currently uses Python's asyncore module for its default event loop. For better performance, libev is also supported through a C extension.

If you're on Linux, you should be able to install libev through a package manager. For example, on Debian/Ubuntu:

$ sudo apt-get install libev4 libev-dev

On RHEL/CentOS/Fedora:

$ sudo yum install libev libev-devel

If you're on Mac OS X, you should be able to install libev through Homebrew. For example, on Mac OS X:

$ brew install libev

If successful, you should be able to build and install the extension (just using setup.py build or setup.py install) and then use the libev event loop by doing the following:

>>> from cassandra.io.libevreactor import LibevConnection
>>> from cassandra.cluster import Cluster

>>> cluster = Cluster()
>>> cluster.connection_class = LibevConnection
>>> session = cluster.connect()

Compression Support

Compression can optionally be used for communication between the driver and Cassandra. There are currently two supported compression algorithms: snappy (in Cassandra 1.2+) and LZ4 (only in Cassandra 2.0+). If either is available for the driver and Cassandra also supports it, it will be used automatically.

For lz4 support:

sudo pip install lz4

For snappy support:

sudo pip install python-snappy

(If using a Debian Linux derivative such as Ubuntu, it may be easier to just run apt-get install python-snappy.)

License

Copyright 2013, DataStax

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.