OpenStack Storage (Swift)
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Samuel Merritt 729430f349 Alternate DiskFile constructor for efficient auditing.
Before, to audit an object, the auditor:
 - calls listdir(object-hash-dir)
 - picks out the .data file from the listing
 - pulls out all N of its user.swift.metadata* xattrs
 - unpickles them
 - pulls out the value for 'name'
 - splits the name into a/c/o
 - then instantiates and opens a DiskFile(a, c, o),
which does the following
 - joins a/c/o back into a name
 - hashes the name
 - calls listdir(object-hash-dir) (AGAIN)
 - picks out the .data file (and maybe .meta) from the listing (AGAIN)
 - pulls out all N of its user.swift.metadata* xattrs (AGAIN)
 - unpickles them (AGAIN)
 - starts reading object's contents off disk

Now, the auditor simply locates the hash dir on the filesystem (saving
one listdir) and then hands it off to
DiskFileManager.get_diskfile_from_audit_location, which then
instantiates a DiskFile in a way that lazy-loads the name later
(saving one xattr reading).

As part of this, DiskFile.open() will now quarantine a hash
"directory" that's actually a file. Before, the audit location
generator would skip those, but now they make it clear into
DiskFile(). It's better to quarantine them anyway, as they're not
doing any good the way they are.

Also, removed the was_quarantined attribute on DiskFileReader. Now you
can pass in a quarantine_hook callable to DiskFile.reader() that gets
called if the file was quarantined. Default is to log quarantines, but
otherwise do nothing.

Change-Id: I04fc14569982a17fcc89e00832725ae71009335a
2013-11-06 11:16:42 -08:00
bin Merge "Faster swift-dispersion-populate" 2013-10-22 17:55:59 +00:00
doc Merge "Faster swift-dispersion-populate" 2013-10-22 17:55:59 +00:00
etc Merge "Faster swift-dispersion-populate" 2013-10-22 17:55:59 +00:00
examples Add a user variable to templates 2013-09-17 11:46:04 +10:00
locale Reverted the pulling out of various middleware: 2012-05-16 21:25:10 +00:00
swift Alternate DiskFile constructor for efficient auditing. 2013-11-06 11:16:42 -08:00
test Alternate DiskFile constructor for efficient auditing. 2013-11-06 11:16:42 -08:00
.coveragerc Align tox.ini and fix coverage jobs in jenkins. 2012-06-08 20:05:14 -04:00
.functests Allow dot test runners from any dir 2012-12-07 14:08:49 -08:00
.gitignore fix(gitignore) : ignore *.egg and *.egg-info 2013-07-30 15:11:00 -04:00
.gitreview Add .gitreview config file for gerrit. 2011-10-24 15:05:49 -04:00
.mailmap Update my mailmap 2013-10-25 16:29:16 +08:00
.probetests Allow dot test runners from any dir 2012-12-07 14:08:49 -08:00
.unittests Add branch coverage reporting 2013-06-10 10:30:40 -04:00
AUTHORS CHANGELOG and AUTHORS updates for 1.10.0 release 2013-10-08 23:58:13 -07:00
babel.cfg add pybabel setup.py commands and initial .pot 2011-01-27 00:01:24 +00:00
CHANGELOG CHANGELOG and AUTHORS updates for 1.10.0 release 2013-10-08 23:58:13 -07:00
CONTRIBUTING.md Add CONTRIBUTING file. 2012-11-21 11:23:15 -08:00
LICENSE Convert LICENSE to use unix style line endings. 2012-12-19 12:48:27 -05:00
MANIFEST.in Add requirements files to the source distribution 2013-06-03 19:26:20 +04:00
README.md Correct URL in readme 2013-10-07 22:27:34 -07:00
requirements.txt Make pbr a build-time only dependency 2013-10-29 12:29:49 -07:00
setup.cfg Migrate to pbr for build 2013-08-14 19:10:07 -03:00
setup.py Migrate to pbr for build 2013-08-14 19:10:07 -03:00
test-requirements.txt Start using Hacking 2013-07-15 11:41:58 +02:00
tox.ini Merge "Add support for POST commit coverage runs" 2013-09-14 00:19:05 +00:00

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