44a861787a
This patch improves EC GET response handling: - The proxy no longer requires all object servers to have a durable file for the fragment archive that they return in response to a GET. The proxy will now be satisfied if just one object server has a durable file at the same timestamp as fragments from other object servers. This means that the proxy can now successfully GET an object that had missing durable files when it was PUT. - The proxy will now ensure that it has a quorum of *unique* fragment indexes from object servers before considering a GET to be successful. - The proxy is now able to fetch multiple fragment archives having different indexes from the same node. This enables the proxy to successfully GET an object that has some fragments that have landed on the same node, for example after a rebalance. This new behavior is facilitated by an exchange of new headers on a GET request and response between the proxy and object servers. An object server now includes with a GET (or HEAD) response: - X-Backend-Fragments: the value of this describes all fragment archive indexes that the server has for the object by encoding a map of the form: timestamp -> <list of fragment indexes> - X-Backend-Durable-Timestamp: the value of this is the internal form of the timestamp of the newest durable file that was found, if any. - X-Backend-Data-Timestamp: the value of this is the internal form of the timestamp of the data file that was used to construct the diskfile. A proxy server now includes with a GET request: - X-Backend-Fragment-Preferences: the value of this describes the proxy's current preference with respect to those fragments that it would have object servers return. It encodes a list of timestamp, and for each timestamp a list of fragment indexes that the proxy does NOT require (because it already has them). The presence of a X-Backend-Fragment-Preferences header (even one with an empty list as its value) will cause the object server to search for the most appropriate fragment to return, disregarding the existence or not of any durable file. The object server assumes that the proxy knows best. Closes-Bug: 1469094 Closes-Bug: 1484598 Change-Id: I2310981fd1c4622ff5d1a739cbcc59637ffe3fc3 Co-Authored-By: Paul Luse <paul.e.luse@intel.com> Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com> |
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|---|---|---|
| api-ref/source | ||
| bin | ||
| doc | ||
| etc | ||
| examples | ||
| install-guide/source | ||
| swift | ||
| test | ||
| .alltests | ||
| .coveragerc | ||
| .functests | ||
| .gitignore | ||
| .gitreview | ||
| .mailmap | ||
| .manpages | ||
| .probetests | ||
| .testr.conf | ||
| .unittests | ||
| AUTHORS | ||
| babel.cfg | ||
| bandit.yaml | ||
| bindep.txt | ||
| CHANGELOG | ||
| CONTRIBUTING.rst | ||
| LICENSE | ||
| MANIFEST.in | ||
| README.rst | ||
| requirements.txt | ||
| REVIEW_GUIDELINES.rst | ||
| 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
Getting Started
Swift is part of OpenStack and follows the code contribution, review, and testing processes common to all OpenStack projects.
If you would like to start contributing, check out these notes to help you get started.
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.
Tests
There are three types of tests included in Swift's source tree.
- Unit tests
- Functional tests
- Probe tests
Unit tests check that small sections of the code behave properly. For example, a unit test may test a single function to ensure that various input gives the expected output. This validates that the code is correct and regressions are not introduced.
Functional tests check that the client API is working as expected. These can be run against any endpoint claiming to support the Swift API (although some tests require multiple accounts with different privilege levels). These are "black box" tests that ensure that client apps written against Swift will continue to work.
Probe tests are "white box" tests that validate the internal workings of a Swift cluster. They are written to work against the "SAIO - Swift All In One" dev environment. For example, a probe test may create an object, delete one replica, and ensure that the background consistency processes find and correct the error.
You can run unit tests with .unittests, functional tests
with .functests, and probe tests with
.probetests. There is an additional .alltests
script that wraps the other three.
Code Organization
- bin/: Executable scripts that are the processes run by the deployer
- doc/: Documentation
- etc/: Sample config files
- examples/: Config snippets used in the docs
- swift/: Core code
- account/: account server
- cli/: code that backs some of the CLI tools in bin/
- common/: code shared by different modules
- middleware/: "standard", officially-supported middleware
- ring/: code implementing Swift's ring
- container/: container server
- locale/: internationalization (translation) data
- obj/: object server
- proxy/: proxy server
- test/: Unit, functional, and probe 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
There is an ops runbook that gives information about how to diagnose and troubleshoot common issues when running a Swift cluster.
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/
There is a large ecosystem of applications and libraries that support and work with OpenStack Swift. Several are listed on the associated projects page.
For more information come hang out in #openstack-swift on freenode.
Thanks,
The Swift Development Team