Swift

A distributed object storage system designed to scale from a single machine to thousands of servers. Swift is optimized for multi-tenancy and high concurrency. Swift is ideal for backups, web and mobile content, and any other unstructured data that can grow without bound.

Swift provides a simple, REST-based API fully documented at http://docs.openstack.org/.

Swift was originally developed as the basis for Rackspace's Cloud Files and was open-sourced in 2010 as part of the OpenStack project. It has since grown to include contributions from many companies and has spawned a thriving ecosystem of 3rd party tools. Swift's contributors are listed in the AUTHORS file.

Docs

To build documentation install sphinx (pip install sphinx), run python setup.py build_sphinx, and then browse to /doc/build/html/index.html. These docs are auto-generated after every commit and available online at http://docs.openstack.org/developer/swift/.

For Developers

The best place to get started is the "SAIO - Swift All In One". This document will walk you through setting up a development cluster of Swift in a VM. The SAIO environment is ideal for running small-scale tests against swift and trying out new features and bug fixes.

You can run unit tests with .unittests and functional tests with .functests.

If you would like to start contributing, check out these notes to help you get started.

Code Organization

• bin/: Executable scripts that are the processes run by the deployer
• doc/: Documentation
• etc/: Sample config files
• swift/: Core code
  • account/: account server
  • common/: code shared by different modules
    • middleware/: "standard", officially-supported middleware
    • ring/: code implementing Swift's ring
  • container/: container server
  • obj/: object server
  • proxy/: proxy server
• test/: Unit and functional tests

Data Flow

Swift is a WSGI application and uses eventlet's WSGI server. After the processes are running, the entry point for new requests is the Application class in swift/proxy/server.py. From there, a controller is chosen, and the request is processed. The proxy may choose to forward the request to a back- end server. For example, the entry point for requests to the object server is the ObjectController class in swift/obj/server.py.

For Deployers

Deployer docs are also available at http://docs.openstack.org/developer/swift/. A good starting point is at http://docs.openstack.org/developer/swift/deployment_guide.html

You can run functional tests against a swift cluster with .functests. These functional tests require /etc/swift/test.conf to run. A sample config file can be found in this source tree in test/sample.conf.

For Client Apps

For client applications, official Python language bindings are provided at http://github.com/openstack/python-swiftclient.

Complete API documentation at http://docs.openstack.org/api/openstack-object-storage/1.0/content/

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For more information come hang out in #openstack-swift on freenode.

Thanks,

The Swift Development Team