index data missing in a particular time period.

[Reethika]

So data of an index missing from a 30thmay to 20th june. I was crosschecking it through epoch time of missing period. I could files in  index/db/  

What does these files mean?

-rw------- 1 root root     0 Jun 10 00:16 rb_1591740508_1591694190_1481_B0964DEC-509D-40A9-A451-529E6E725A5F.rbsentinel
drwx------ 3 root root  4096 Jun 10 09:11 rb_1591743776_1591657655_2201_7934D4E6-9F8E-4A10-9002-279FAC932938

But still data isn't reflecting on search.

Is my troubleshooting wrong for missing indexes. Any recommended troubleshooting? 

Thanks.

[richgalloway · Accepted solution]

The "rb_" says these are replicated buckets.
The "rbsentinel" file is used for directory locking.
The second directory is for data between 8 June 20 23:05:35Z and 9 June 20 23:02:56Z.
The part after the last "_" is the GUID of the originating indexer.