Mappings conflict after rollover

[lstoneir (lal ston)]

I have an index with name X-001
with this mapping:

{
"time": {
        "type": "date"
      }
}

after linking index to ilm, and rollover action:
elastic creates index X-002 but in mapping i see this :

{
"time": {
        "type": "long"
      }
}

why this happened? and how can i fix this?

index pattern error:

Mapping conflict
2 fields are defined as several types (string, integer, etc) across the indices that match this pattern. You may still be able to use these conflict fields in parts of Kibana, but they will be unavailable for functions that require Kibana to know their type. Correcting this issue will require reindexing your data.

[rugenl (Len Rugen)]

Check the elasticsearch log when X-002 was created, see what templates contributed to field mapping. The template priority controls the order they are applied. Make sure the time mapping is correct in the winning template.

If you don't have time mapped, then the first time the field is encountered, dynamic mapping tries to guess what format to use. If different formats come from different sources, then randomly, whichever is encountered first sets the mapping.