The persisted counters will be used to surface estimates about the resharding operation in $currentOp. Persisting and replicating the metrics enables $currentOp to report these estimates following a primary failover or server restart.

• The metrics from the "resharding" section in server status can be a starting point for the ones to persist. It should also be possible to reinitialize the in-memory counters from the persisted state.
• The counters for the number of successful, failed, and user-canceled resharding operations need not be persisted. The counters therefore need not be persisted on the config server.