Highlight hits within attachment content with ElasticSearch - elasticsearch

Question

I'm having trouble getting ElasticSearch to highlight hits within attachment content indexed using the elasticsearch-mapper-attachments.
My data at /stuff/file looks like this:
{
"id": "string"
"name": "string"
"attachment": "...base 64 encoded file"
}
My mapper configuration put to /stuff/file/_mapper looks like this:
{
"file" : {
"properties" : {
"attachment" : {
"type" : "attachment",
"path" : "full",
"fields": {
"name": { "store": true },
"title": { "store": true },
"content": { "store": true },
"attachment": {
"type": "string",
"term_vector": "with_positions_offsets",
"store": true
}
}
}
}
}
}
And when I query it at /stuff/_mapper/file I get this returned:
{
"stuff":{
"mappings":{
"file":{
"properties":{
"attachment":{
"type":"attachment",
"path":"full",
"fields":{
"attachment":{
"type":"string"
},
"author":{
"type":"string"
},
"title":{
"type":"string"
},
"name":{
"type":"string"
},
"date":{
"type":"date",
"format":"dateOptionalTime"
},
"keywords":{
"type":"string"
},
"content_type":{
"type":"string"
},
"content_length":{
"type":"integer"
},
"language":{
"type":"string"
}
}
},
"id":{
"type":"string"
},
"name":{
"type":"string"
}
}
}
}
}
}
And my query looks like this:
{
"size": 30,
"query": {
"multi_match": {
"query": "{{.Query}}",
"operator": "and",
"fields": ["id", "name^4", "attachment"],
"fuzziness": "AUTO",
"minimum_should_match": "80%"
}
},
"highlight" : {
"fields" : {
"attachment": { }
}
}
}
When I search for a term that is in the attachment, it returns the correct result but there is no highlighting. There was a similar question from a few years ago that swapped attachment for file in a few places but there were comments that this has changed again... What's the right configuration to get the highlighting to work?

Answer 1

Turns out that you can't overwrite mapper configurations using PUT. You need to delete the existing configuration first (I actually had delete the entire database, DELETE on the configuration didn't seem to have any effect). Once the mapper configuration was actually updated, highlighting works fine.