523bc0ab71
Previously, we would set the TZ environment variable to the result of
time.strftime("%z", time.gmtime())
This has a few problems.
1. The "%z" format does not appear in the table of formatting
directives for strftime [1]. While it *does* appear in a
footnote [2] for that section, it is described as "not supported by
all ANSI C libraries." This may explain the next point.
2. On the handful of Linux platforms I've tested, the above produces
"+0000" regardless of the system's timezone. This seems to run
counter to the intent of the patches that introduced the TZ
mangling. (See the first two related changes.)
3. The above does not produce a valid Posix TZ format, which expects
(at minimum) a name consisting of three or more alphabetic
characters followed by the offset to be added to the local time to
get Coordinated Universal Time (UTC).
Further, while we would change os.environ['TZ'], we would *not* call
time.tzset like it says in the docs [3], which seems like a Bad Thing.
Some combination of the above has the net effect of changing some of the
functions in the time module to use UTC. (Maybe all of them? At the very
least, time.localtime and time.mktime.) However, it does *not* change
the offset stored in time.timezone, which causes bad behavior when
dealing with local timestamps [4].
Now, set TZ to "UTC+0" and call tzset. Apparently we don't have a good
way of getting local timezone info, we were (unintentionally?) using UTC
before, and you should probably be running your servers in UTC anyway.
[1] https://docs.python.org/2/library/time.html#time.strftime
[2] https://docs.python.org/2/library/time.html#id2
[3] https://docs.python.org/2/library/time.html#time.tzset
[4] Like in email.utils.mktime_tz, prior to being fixed in
https://hg.python.org/cpython/rev/a283563c8cc4
Change-Id: I007425301914144e228b9cfece5533443e851b6e
Related-Change: Ifc78236a99ed193a42389e383d062b38f57a5a31
Related-Change: I8ec80202789707f723abfe93ccc9cf1e677e4dc6
Related-Change: Iee7488d03ab404072d3d0c1a262f004bb0f2da26
|
||
|---|---|---|
| api-ref/source | ||
| bin | ||
| doc | ||
| etc | ||
| examples | ||
| install-guide/source | ||
| releasenotes | ||
| 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 | ||
Team and repository tags
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