When Versioning is Enabled

When you enable or suspend versioning, the existing objects in your domain or bucket do not change: what changes is how Swarm handles future requests. 

Once versioning is enabled in a context, Swarm uses each object's metadata to walk a virtual chain of versions of an object, from creation to deletion:

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The order of the versions is the creation order, with the most recent one always being the current version.

These virtual version chains are extremely resilient: Swarm linearizes the linkage so the newest version of an object links to the next in the ordering, which links to the next, and Swarm's health processing guarantees temporarily broken chains are repaired. Swarm orders all versions by the time they are written, regardless of the operations that created them.

All usual SCSP operations act on the current version, which is the most recently updated one, unless a previous version is mentioned on the request.

Key Principles: These principles apply across all versioning operations, whether versioning is enabled or suspended:

• Regular operations always act on the current version of the object.

• Every version of each object - including a delete marker - is identified by its version identifier, which is its ETag value.

• Operations that include the version query argument (https://perifery.atlassian.net/wiki/spaces/public/pages/2443821292) always act on the specific version alone, even the current version.

See https://perifery.atlassian.net/wiki/spaces/public/pages/2443812462 and https://perifery.atlassian.net/wiki/spaces/public/pages/2443812514.

When Versioning is Suspended

Suspending versioning allows new versions of the same object to stop accruing without jeopardizing the set of versions that already exists.

When you suspend versioning, existing objects in your domain or bucket do not change: what changes is how Swarm handles future requests. You can re-enable versioning to have Swarm resume versioning behavior where it left off.

• New Objects: No versions are created for any objects created after versioning is suspended.

• Updating Objects: Swarm retains all existing versions when the versioning state is changed to suspended. After that, any update creates a new current version, which is overwritten with updates after that. 

• Retrieving Objects: Regardless of the versioning state of the domain or bucket, GET Object requests return the current version of an object.

• Deleting Objects: If versioning is suspended, a DELETE request creates a delete marker for the object. You can also delete a specified version, which permanently removes that object.