I was able to find the source of the problem with that exception.
ElasticSearch mapping allows for “ignore_malformed” : true setting.
If this is done, then elasticsearch knows how to ignore it, but Dremio does not.
So for example, putting a mapping including -
“mytime” : {
“type” : “date”,
“ignore_malformed” : true
}
will allow to insert document with “mytime” : "2014-03-01 12:13:42"
even though elasticsearch does not allow such a date format.
This will casue Dremio to fail while trying even to browse the type, and will make it unusable.