Elasticsearch Delete Mapping Property - json

Question

I am trying to figure out an approach to delete all entries for a specific property in an elasticsearch index and remove all type mappings for that property.
I have been looking at the following two doc pages: put mapping and delete mapping
From second link:
"Allow to delete a mapping (type) along with its data. The REST
endpoint is /{index}/{type} with DELETE method."
What I think I need is a /{index}/{type}/{property}?
Do I need to recreate the whole index to accomplish this, i.e. moving and manipulating data between types?
For Example, calling GET on the mapping:
curl -XGET 'http://.../some_index/some_type/_mapping'
result:
{
"some_type": {
"properties": {
"propVal1": {
"type": "double",
"index": "analyzed"
},
"propVal2": {
"type": "string",
"analyzer": "keyword"
},
"propVal3": {
"type": "string",
"analyzer": "keyword"
}
}
}
}
after this delete operation on propVal3 would return:
curl -XGET 'http://.../some_index/some_type/_mapping'
result:
{
"some_type": {
"properties": {
"propVal1": {
"type": "double",
"index": "analyzed"
},
"propVal2": {
"type": "string",
"analyzer": "keyword"
}
}
}
}
and all data for propVal3 would be removed through the index.

Answer 1

You can not do that. Just forget that this value exists... ;-)
If you really need to remove it, you will have to reindex your documents.

Answer 2

You can use the new _reindex api for this, you could even PUT a new _mapping to the dest index before running the reindex so you can change the properties of the fields in your index.
To do a reindex and removing a property, you can do this:
POST /_reindex
{
"source": {
"index": "twitter"
},
"dest": {
"index": "new_twitter",
},
"script": {
"inline": "ctx._source.remove('whatever')"
}
}
if you would use this in combination with the _aliases API you can modify indexes without having any 'downtime'

Answer 3

It's not currently possible to remove a property from a mapping. In order to remove all values of a property from all records, you need to reindex all records with this property removed.

Answer 4

You can choose whats documents fields you will reindex to a new index. For example:
POST _reindex
{
"source": {
"index": "my-source-index",
"_source": ["host.hostname", "host.ip", "another_field"]
},
"dest": {
"index": "my-dest-index"
}
}
Reference: https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-reindex.html#docs-reindex-filter-source

Answer 5

Just want to add another approach for the case of "removing property from index".
POST pulse/_update_by_query
{
"query": {
"match_all": {}
},
"script": {
"source": "ctx._source.remove(\"file_id\")",
"lang": "painless"
}
}