Custom metadata collisions

Content Platform Tenant Management Help

Version
9.7.x
File Size
4269 KB
Audience
anonymous
Part Number
MK-95HCPH002-19

A custom metadata collision occurs when these events occur in the order shown:

  1. One of these changes occurs:
    • An annotation is added with the same name to a given object on each of two systems in a replication topology, but the annotation has different content on the two systems.

      The addition of an annotation to a given object on only one of the systems does not result in a custom metadata collision if the object does not have an annotation with the same name on the other system. In this case, the new annotation is replicated without conflict.

    • Different changes are made to the content of a given annotation for a given object on each of the two systems in a replication topology.
    • A change is made to the content of a given annotation for a given object on one system in a replication topology, and the same annotation is deleted on another system in the topology.
  2. The change made on one of the systems is replicated to the other system.

If a collision occurs when a custom metadata change for a given object is replicated from one system (system A) in a replication topology to another system (system B) in the topology:

  • If the last change on system A is more recent than the last change on system B, HCP applies the change from system A to the custom metadata on system B
  • If the last change on system B is more recent than the last change on system A, HCP does not change the custom metadata on system B
Here are two examples of how HCP handles collisions when custom metadata changes for a given object are replicated from one system (system A) in a replication topology to another system (system B) in the topology.

Example 1

The object starts out with annotations named a1 and a2 on both system A and system B.

The list below shows a sequence of events in which the annotations for the object are changed and the changes are then replicated.

  1. On system B, a client changes the content of a1.
  2. On system A, a client makes a different change to the content of a1.
  3. On system A, a client adds annotation a3 to the object.
  4. On system B, a client adds annotation a3 with different content from the a3 added on system A.
  5. The changes on system A are replicated to system B. The resulting annotations for the object on system B are:
    • a1 with the changed content from system A
    • a2 (unchanged)
    • a3 with the content added on system B
  6. The changes on system B are replicated to system A. The resulting annotations for the object on system A are:
    • a1 with the changed content from system A
    • a2 (unchanged)
    • a3 with the content added on system B

Example 2

The object starts out with the annotations named a1, a2, and a3 on both system A and system B.

The list below shows a sequence of events in which the annotations for the object are changed and the changes are then replicated.

  1. On system B, a client changes the content of a1.
  2. On system A, a client deletes a1.
  3. On system A, a client changes the content of a2.
  4. On system B, a client changes the content of a2.
  5. On system A, a client deletes a3.
  6. On system B, a client changes the content of a3.
  7. The changes on system A are replicated to system B. The resulting annotations for the object on system B are:
    • a2 with the changed content from system B
    • a3 with the changed content from system B
  8. The changes on system B are replicated to system A, the resulting annotations for the object on system A are:
    • a2 with the changed content from system B
    • a3 with the changed content from system B