OpenStack Storage (Swift)
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Peter Portante 5202b0e586 DiskFile API, with reference implementation
Refactor on-disk knowledge out of the object server by pushing the
async update pickle creation to the new DiskFileManager class (name is
not the best, so suggestions welcome), along with the REPLICATOR
method logic. We also move the mount checking and thread pool storage
to the new ondisk.Devices object, which then also becomes the new home
of the audit_location_generator method.

For the object server, a new setup() method is now called at the end
of the controller's construction, and the _diskfile() method has been
renamed to get_diskfile(), to allow implementation specific behavior.

We then hide the need for the REST API layer to know how and where
quarantining needs to be performed. There are now two places it is
checked internally, on open() where we verify the content-length,
name, and x-timestamp metadata, and in the reader on close where the
etag metadata is checked if the entire file was read.

We add a reader class to allow implementations to isolate the WSGI
handling code for that specific environment (it is used no-where else
in the REST APIs). This simplifies the caller's code to just use a
"with" statement once open to avoid multiple points where close needs
to be called.

For a full historical comparison, including the usage patterns see:
https://gist.github.com/portante/5488238

(as of master, 2b639f5, Merge
 "Fix 500 from account-quota     This Commit
 middleware")
--------------------------------+------------------------------------
                                 DiskFileManager(conf)

                                   Methods:
                                     .pickle_async_update()
                                     .get_diskfile()
                                     .get_hashes()

                                   Attributes:
                                     .devices
                                     .logger
                                     .disk_chunk_size
                                     .keep_cache_size
                                     .bytes_per_sync

DiskFile(a,c,o,keep_data_fp=)    DiskFile(a,c,o)

  Methods:                         Methods:
   *.__iter__()
    .close(verify_file=)
    .is_deleted()
    .is_expired()
    .quarantine()
    .get_data_file_size()
                                     .open()
                                     .read_metadata()
    .create()                        .create()
                                     .write_metadata()
    .delete()                        .delete()

  Attributes:                      Attributes:
    .quarantined_dir
    .keep_cache
    .metadata
                                *DiskFileReader()

                                   Methods:
                                     .__iter__()
                                     .close()

                                   Attributes:
                                    +.was_quarantined

DiskWriter()                     DiskFileWriter()

  Methods:                         Methods:
    .write()                         .write()
    .put()                           .put()

* Note that the DiskFile class   * Note that the DiskReader() object
  implements all the methods       returned by the
  necessary for a WSGI app         DiskFileOpened.reader() method
  iterator                         implements all the methods
                                   necessary for a WSGI app iterator

                                 + Note that if the auditor is
                                   refactored to not use the DiskFile
                                   class, see
                                   https://review.openstack.org/44787
                                   then we don't need the
                                   was_quarantined attribute

A reference "in-memory" object server implementation of a backend
DiskFile class in swift/obj/mem_server.py and
swift/obj/mem_diskfile.py.

One can also reference
https://github.com/portante/gluster-swift/commits/diskfile for the
proposed integration with the gluster-swift code based on these
changes.

Change-Id: I44e153fdb405a5743e9c05349008f94136764916
Signed-off-by: Peter Portante <peter.portante@redhat.com>
2013-10-17 15:03:31 -04:00
bin Revert "Refactor common/utils methods to common/ondisk" 2013-10-07 17:18:09 -04:00
doc DiskFile API, with reference implementation 2013-10-17 15:03:31 -04:00
etc add reseller_admin_role to sample config 2013-09-05 12:27:18 -07:00
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 DiskFile API, with reference implementation 2013-10-17 15:03:31 -04:00
test DiskFile API, with reference implementation 2013-10-17 15:03:31 -04:00
.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 CHANGELOG and AUTHORS updates for 1.10.0 release 2013-10-08 23:58:13 -07:00
.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 Allow slightly older dnspython (>= 1.9.4). 2013-10-02 09:57:34 -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