System metadata collisions
A system metadata collision occurs when these events occur in the order shown:
- Different changes are made to the system metadata for a given object on each of two systems in a replication topology.
- The changed system metadata on one of the systems is replicated to the other system.
If a collision occurs when changed system metadata for a given object is replicated from one system (system A) in a replication topology to another system (system B) in the topology:
- For changed system metadata other than the retention setting and hold status:
- If the last change made on system A is more recent than the last change made on system B, HCP changes the system metadata on system B to match the system metadata on system A.
- If the last change on system B is more recent than the last change on system A, HCP does not change the system metadata on system B.
- For a changed retention setting:
- If the retention setting on system A specifies a longer retention period than does the retention setting on system B, HCP changes the retention setting on system B to match the retention setting on system A.
- If the retention setting on system B specifies a longer retention period than does the retention setting on system A, HCP does not change the retention setting on system B.
- For a changed hold status:
- If the object is on hold on system A but not on system B, HCP places the object on hold on system B.
- If the object is on hold on system B but not on system A, HCP leaves the object on hold on system B.
Example 1
The object starts out on both system A and system B with these system metadata settings:
- Shred: false
- Index: false
The list below shows a sequence of events in which the system metadata for the object is changed and the changes are then replicated.
- On system A, a client changes the shred setting to true.
- On system B, a client changes the index setting to true.
- The changes on system A are replicated to system B. The resulting settings for the object on system B are:
- Shred: false
- Index: true
Example 2
The object starts out on both system A and system B with these system metadata settings:
- Retention: Initial Unspecified
- Shred: false
- Index: false
The list below shows a sequence of events in which the system metadata for the object is changed and the changes are then replicated.
- On system A, a client changes the retention setting to Deletion Prohibited.
- On system B, a client changes the retention setting to Deletion Allowed.
- On system B, a client changes the index setting to true.
- On system A, a client changes the shred setting to true.
- The changes on system A are replicated to system B. The resulting settings for the object on system B are:
- Retention: Deletion Prohibited
- Shred: true
- Index: false
Example 3
The object starts out on both system A and system B with these system metadata settings:
- Retention: Initial Unspecified
- Hold: true
- Shred: false
- Index: false
The list below shows a sequence of events in which the system metadata for the object is changed and the changes are then replicated.
- On system A, a client changes the retention setting to Deletion Allowed.
- On system B, a client changes the retention setting to Deletion Prohibited.
- On system B, a client changes the index setting to true.
- On system A, a client changes the shred setting to true.
- On system A, a client releases the object from hold.
- The changes on system A are replicated to system B. The resulting settings for the object on system B are:
- Retention: Deletion Prohibited
- Hold: true
- Shred: true
- Index: false
- The changes on system B are replicated to system A. The resulting settings for the object on system A are:
- Retention: Deletion Prohibited
- Hold: true
- Shred: true
- Index: false