Hemant Rajput, Can you please elaborate your requirements around the persistence? Currently, we have two types of persistences (a) Flat file (b) Snapshot. Flat file persistence happens every 15 min. This interval is configurable. Snapshotting happens every 10 minutes and it is per index. I don't think it is a good idea to change snapshotting interval in recovery tests.
So, I am thinking to persist the stat in a file on disk and read it back when recovering. If you need more fine grained interval, change the "indexer.statsPersistenceInterval" to a less value (currently at 900). I believe this will give you enough control over the stat. Please let me know if you have any other requirement.