Hi, I have an elasticsearch index with dynamic field mapping. I am inserting a log into the index with a field
start_time in the RFC3339 format (e.g. "2020-07-15T23:45:16Z") and until today this field was getting discovered as a date.
However in the new index we created today, it was discovered as a keyword instead. We did just upgrade to ES 7.4, but it's not clear to me why that would have affected anything.
Now when we try to run queries in Kibana, they fail and we see the error
Field [start_time] of type [keyword] does not support custom formats
Is there a good way to make sure this doesn't happen? I'm also not understanding the failure. I get that it could cause queries that use the field to give unexpected results, but I don't know why it would be "unsupported", or why it would cause queries that don't involve that field to fail.
I'd really appreciate some advice, thank you!