46c68aebd1
The basic idea here is to replace the use of a single object ring in
the Application class with a collection of object rings. The
collection includes not only the Ring object itself but the policy
name associated with it, the filename for the .gz and any other
metadata associated with the policy that may be needed. When
containers are created, a policy (thus a specific obj ring) is
selected allowing apps to specify policy at container creation time
and leverage policies simply by using different containers for object
operations.
The policy collection is based off of info in the swift.conf file.
The format of the sections in the .conf file is as follows:
swift.conf format:
[storage-policy:0]
name = chicken
[storage-policy:1]
name = turkey
default = yes
With the above format:
- Policy 0 will always be used for access to existing containers
without the policy specified. The ring name for policy 0 is always
'object', assuring backwards compatiblity. The parser will always
create a policy 0 even if not specified
- The policy with 'default=yes' is the one used for new container
creation. This allows the admin to specify which policy is used without
forcing the application to add the metadata.
This commit simply introduces storage policies and the loading
thereof; nobody's using it yet. That will follow in subsequent
commits.
Expose storage policies in /info
DocImpact
Implements: blueprint storage-policies
Change-Id: Ica05f41ecf3adb3648cc9182f11f1c8c5c678985
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.
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/
For more information come hang out in #openstack-swift on freenode.
Thanks,
The Swift Development Team