8d20e0e927
Currently if the object-expirer goes to delete an object and the primary nodes are unavailable, or the object is on handoffs - the object servers are unable to verify the x-if-delete-at timestamp and return 412, without writing a tombstone or updating the containers. The expirer treats 412 as success and the dark data is not removed form the object servers nor the object removed in the listing. As a side effect of this bug, if the expirer encounters split brain the delete would never get processed in the correct storage policy. It seems it's just not correct to treat the lack of data as success. Now the object server will treat x-if-delete at against a non-existent object as a 404, and to distinguish from a successfull process of an x-if-delete-at request, will return 204. The expirer will treat a 404 response from swift as a failure, and will continue to attempt to expire the object until it is older that it's configurable reclaim age. However swift will only return 404 if the majority of nodes are able to return success, or if only even a single node is able to accept the x-if-delete-at request the containers will get updated and replicaiton will settle the tombstone - the subsequent x-if-delete-at request will 412 and be removed from the queue. It's worth noting that if an object with x-delete-at meta is DELETED (by a client request) an async update for the expiring update containers will be processed to remove the queue entry - but if no primary nodes handle the DELETE request replication will never remove the expiring entry and assuming it's scheduled for beyond the tombstones reclaim age - the queue entry will not be processable. In this case the expirer will attempt to DELETE the object (and get 404s) in vain until the queue entry passes the configurable reclaim age. DocImpact Implements: blueprint storage-policies Change-Id: I66260e99fda37e97d6d2470971b6f811ee9e01be |
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| bin | ||
| doc | ||
| etc | ||
| examples | ||
| locale | ||
| swift | ||
| test | ||
| .coveragerc | ||
| .functests | ||
| .gitignore | ||
| .gitreview | ||
| .mailmap | ||
| .probetests | ||
| .unittests | ||
| AUTHORS | ||
| babel.cfg | ||
| CHANGELOG | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| MANIFEST.in | ||
| README.md | ||
| requirements.txt | ||
| setup.cfg | ||
| setup.py | ||
| test-requirements.txt | ||
| tox.ini | ||
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