HCP System Management Help
An object content collision occurs when:
1.Two objects with the same name are created in a replicated container on two systems in a replication topology, and the object has different content on the two systems.
2.The object on one of the systems is replicated to the other system.
If versioning is enabled for the container (through the Tenant Management Console), no collision occurs. Instead, the less recently created of the two objects becomes an old version of the more recently created object.
When an object content collision occurs, the more recently created object keeps its name and location. The other object is either moved to the .lost+found directory in the same container or renamed, depending on the container configuration.
When HCP moves an object to the .lost+found directory, the full object path becomes .lost+found/replication/system-generated-directory/
old-object-path.
When renaming an object due to a content collision, HCP changes the object name to object-name.collision or object-name.version-id.collision, where version-id is the version ID of the object. HCP uses the second format only if versioning has at one point been enabled for the namespace that contains the object but is not currently enabled.
If the new name is already in use, HCP changes the object name to object-name.1.collision or object-name.version-id.1.collision, as applicable. If that name is already in use, HCP successively increments the middle integer by one until a unique name is formed.
Objects that have been relocated or renamed due to content collisions are flagged as replication collisions in their system metadata. You can use the metadata query API to search for objects that are flagged as replication collisions.
If an object that’s flagged as a replication collision changes (for example, the object ACL changes), its collision flag is removed. If you create a copy of a flagged object with a new name, the collision flag is not set on the copy.
Depending on the container configuration, objects flagged as replication collisions may be automatically deleted after a set number of days. The days are counted from the time the collision flag is set. If the collision flag is removed from an object, the object is no longer eligible for automatic deletion.
You cannot use the HSwift API to change the way HCP handles objects that are flagged as replication collisions. However, tenant administrators can change this configuration for the containers you create.
For information the metadata query API, see HCP Metadata Query API Reference.
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