I have the really weird issue with ES 2.4. Really appreciate if someone would explain me how to fix it.
I have an index with one unique field 'some_id' inside - and the value of that field is used as object ID.
Total count of records is 756,451 - and all field values are unique (since used in doc ID).
Now I am running cardinality and value_count aggr (see request below).
value_count gives me 3,782,132 -- it's 5x more than the total count!!
cardinality - 1,598,725 -- 2x more than total count
We store UUID in this some_id field, so values look like '06e58e84-e8ad-4d5f-be00-17f2b18ff668' etc (all unique).
Any idea why it happens? I realize that cardinality and value_count are approx counts - but I didn't expect it has 200-500% error rate!!!