OpenStack Storage (Swift)
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Matthew Oliver 2641814010 Add sharder daemon, manage_shard_ranges tool and probe tests
The sharder daemon visits container dbs and when necessary executes
the sharding workflow on the db.

The workflow is, in overview:

- perform an audit of the container for sharding purposes.

- move any misplaced objects that do not belong in the container
  to their correct shard.

- move shard ranges from FOUND state to CREATED state by creating
  shard containers.

- move shard ranges from CREATED to CLEAVED state by cleaving objects
  to shard dbs and replicating those dbs. By default this is done in
  batches of 2 shard ranges per visit.

Additionally, when the auto_shard option is True (NOT yet recommeneded
in production), the sharder will identify shard ranges for containers
that have exceeded the threshold for sharding, and will also manage
the sharding and shrinking of shard containers.

The manage_shard_ranges tool provides a means to manually identify
shard ranges and merge them to a container in order to trigger
sharding. This is currently the recommended way to shard a container.

Co-Authored-By: Alistair Coles <alistairncoles@gmail.com>
Co-Authored-By: Tim Burke <tim.burke@gmail.com>
Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com>

Change-Id: I7f192209d4d5580f5a0aa6838f9f04e436cf6b1f
2018-05-18 18:48:13 +01:00
api-ref/source Merge "Replace Chinese punctuation with English punctuation" 2018-01-31 01:48:12 +00:00
bin Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
doc Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
etc Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
examples Add a user variable to templates 2013-09-17 11:46:04 +10:00
playbooks Capture probe test logs 2018-03-12 23:10:24 +00:00
releasenotes Imported Translations from Zanata 2018-03-01 06:49:57 +00:00
swift Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
test Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
tools Add swift probe tests to gate 2018-03-06 06:57:53 -05:00
.alltests Apply bash error handling consistently in all bash scripts 2016-10-11 22:13:06 +02:00
.coveragerc Show missing branches in coverage report. 2017-12-14 14:57:48 -08:00
.functests Improved usage of args in .functests 2018-02-14 12:31:17 -08:00
.gitignore Ignore directory .stestr 2018-01-04 20:40:11 -08:00
.gitreview updated .gitreview 2018-04-30 10:49:41 -07:00
.mailmap authors/changelog updates for 2.17.0 release 2018-02-02 12:09:20 -08:00
.manpages Script for checking sanity of manpages 2016-02-10 14:16:56 -08:00
.probetests Allow specify arguments to .probetests script 2013-12-24 01:18:19 -08:00
.testr.conf Fix func test --until-failure and --no-discover options 2015-12-16 15:28:25 +00:00
.unittests Fix coverage report for newer versions of coverage 2014-04-24 16:50:03 +00:00
.zuul.yaml Import swift3 into swift repo as s3api middleware 2018-04-27 15:53:57 +09:00
AUTHORS Import swift3 into swift repo as s3api middleware 2018-04-27 15:53:57 +09:00
babel.cfg add pybabel setup.py commands and initial .pot 2011-01-27 00:01:24 +00:00
bandit.yaml Updating Bandit config file 2016-09-16 09:20:34 -07:00
bindep.txt Import swift3 into swift repo as s3api middleware 2018-04-27 15:53:57 +09:00
CHANGELOG Trivial: Update pypi url to new url 2018-04-20 17:30:47 +07:00
CONTRIBUTING.rst doc migration: update the doc link address[2/3] 2017-09-15 06:31:00 +00:00
LICENSE Convert LICENSE to use unix style line endings. 2012-12-19 12:48:27 -05:00
MANIFEST.in Fix locale directory in MANIFEST.in 2016-05-19 15:56:15 +02:00
README.rst Update links in README 2018-03-11 02:42:48 +08:00
requirements.txt Import swift3 into swift repo as s3api middleware 2018-04-27 15:53:57 +09:00
REVIEW_GUIDELINES.rst added a quote 2017-01-05 10:24:09 -08:00
setup.cfg Add sharder daemon, manage_shard_ranges tool and probe tests 2018-05-18 18:48:13 +01:00
setup.py taking the global reqs that we can 2014-05-21 09:37:22 -07:00
test-requirements.txt Import swift3 into swift repo as s3api middleware 2018-04-27 15:53:57 +09:00
tox.ini Merge "Import swift3 into swift repo as s3api middleware" 2018-04-30 16:00:56 +00:00

Team and repository tags

image

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 https://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 https://docs.openstack.org/swift/latest/.

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.

  1. Unit tests
  2. Functional tests
  3. 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.

To fully run the tests, the target environment must use a filesystem that supports large xattrs. XFS is strongly recommended. For unit tests and in-process functional tests, either mount /tmp with XFS or provide another XFS filesystem via the TMPDIR environment variable. Without this setting, tests should still pass, but a very large number will be skipped.

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 https://docs.openstack.org/swift/latest/. A good starting point is at https://docs.openstack.org/swift/latest/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 https://github.com/openstack/python-swiftclient.

Complete API documentation at https://developer.openstack.org/api-ref/object-store/

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