Ceph » rgw

radosgw-admin provides commands to clear the sync status for metadata, data, and bucket sync. the intent is to force radosgw to restart a full sync

however, radosgw doesn't notice this empty sync status (at least for metadata and data sync) until the gateway is restarted. and, if incremental sync is already in progress, it may overwrite the sync status and avoid triggering a full sync altogether

so where possible, changes to these sync status objects should be guarded by cls_version to detect racing writes; and when multisite sync is trying to write out an updated marker but gets notified of a race via ECANCELED, it should back out and reread the sync status