OpenStack Swift is a distributed object storage system engineered to scale from single machines to thousands of servers, optimized for multi-tenancy and high concurrency workloads. The system provides a simple REST-based API and is particularly well-suited for backups, web and mobile content, and unstructured data that grows without defined limits. Swift originated as the foundation for Rackspace's Cloud Files before being open-sourced in 2010 as part of the OpenStack project, and has since accumulated contributions from numerous companies while fostering a substantial ecosystem of third-party tools.
The repository is written in Python and functions as a WSGI application using eventlet's WSGI server. Request processing begins at the Application class in swift/proxy/server.py, where a controller is selected to handle the incoming request. The proxy server can forward requests to backend servers, with the ObjectController class in swift/obj/server.py serving as the entry point for object server requests. This architecture enables the system to distribute storage and processing across multiple nodes in a cluster.
Swift's testing infrastructure comprises three distinct test types. Unit tests validate that small code sections behave correctly, such as testing individual functions with various inputs to ensure correctness and prevent regressions. Functional tests verify that the client API operates as expected and can run against any endpoint supporting the Swift API, functioning as black box tests to ensure client applications continue working properly. Probe tests serve as white box tests validating internal cluster workings and are designed to run against the SAIO development environment, for example creating objects, deleting replicas, and verifying that background consistency processes detect and correct errors. The repository includes test execution scripts for unit tests, functional tests, probe tests, and a comprehensive alltests script. Full test execution requires a filesystem supporting large extended attributes, with XFS strongly recommended.
GitGenius activity data indicates this is an actively maintained project with ongoing issue and pull request activity reflecting its role as a critical infrastructure component. The repository has been classified across multiple domains including durable storage, distributed filesystems, data durability, object storage, cloud computing, data redundancy, multitenancy, and fault tolerance, reflecting its comprehensive feature set. The system implements data replication and redundancy mechanisms essential for reliable distributed storage, while supporting scalability across storage clusters and distributed systems.
Documentation is automatically generated after each commit and available at https://docs.openstack.org/swift/latest/. The repository includes deployment guides and an operations runbook providing diagnostic and troubleshooting information for running Swift clusters. Functional tests can be executed against deployed Swift clusters using configuration files, while official Python language bindings are maintained separately at https://opendev.org/openstack/python-swiftclient. The complete API reference is available at https://docs.openstack.org/api-ref/object-store/, and the associated projects page documents the broader ecosystem of applications and libraries supporting OpenStack Swift.
