Object names of directory objects qualified for ExpiredObjectAllVersions
must be encoded appropriately before calling on deletePrefix on their
erasure set.
e.g., a directory object and regular objects with overlapping prefixes
could lead to the expiration of regular objects, which is not the
intention of ILM.
```
bucket/dir/ ---> directory object
bucket/dir/obj-1
```
When `bucket/dir/` qualifies for expiration, the current implementation would
remove regular objects under the prefix `bucket/dir/`, in this case,
`bucket/dir/obj-1`.
Simplify MRF queueing and add backlog handler
- Limit re-tries to 3 to avoid repeated re-queueing. Fall offs
to be re-tried when the scanner revisits this object or upon access.
- Change MRF to have each node process only its MRF entries.
- Collect MRF backlog by the node to allow for current backlog visibility
This PR improves the replication failure healing by persisting
most recent failures to disk and re-queuing them until the replication
is successful.
While this does not eliminate the need for healing during a full scan,
queuing MRF vastly improves the ETA to keeping replicated buckets
in sync as it does not wait for the scanner visit to detect unreplicated
object versions.
Krishnan Parthasarathi
Poorna