How to solve "Fielddata is disabled on text fields by default"

[jcaballero (Jose)]

Hi [again],

I already opened a while ago a Topic on this issue, but it expired. So I am opening a new one.

https://discuss.elastic.co/t/how-to-apply-mappings-just-once/181280

ElasticSearch 5.6.10

When I try to sort in Kibana a given field from data in ElasticSearch, I get the famous message "Fielddata is disabled on text fields by default". So I need to:

1. convert that field for all existing indices
2. make it that new indices, created daily, have already the right settings

I was pointed to https://www.elastic.co/guide/en/elasticsearch/reference/5.6/indices-templates.html

but I have to admit I don't fully understand it.
From what I have read in other parts of the documentation, it is not possible to modify existing indices. Right?

If not possible to get 1. and 2., then my priority is 2.
I have tried to apply a template for a fake index that does not exist yet, like this

 curl -X PUT "my.elasticsearch.host:9200/_template/template_1" -H 'Content-Type: application/json' -d'
{
  "template": "test*",
  "settings" : {
    "number_of_shards":1
  },
  "mappings": {
    "log": {
        "_source": {
          "enabled": false
        },
        "properties": {
          "user": {
            "type": "keyword"
          }
        }
    }
  }
}
'

and then tried to add a few documents to several indices:

curl -X PUT "my.elasticsearch.host:9200/test-1/log/1?pretty" -H 'Content-Type: application/json' -d '{ "user": "joe"}'
curl -X PUT "my.elasticsearch.host:9200/test-1/log/2?pretty" -H 'Content-Type: application/json' -d '{ "user": "jane"}'
curl -X PUT "my.elasticsearch.host:9200/test-2/log/1?pretty" -H 'Content-Type: application/json' -d '{ "user": "dan"}'
curl -X PUT "my.elasticsearch.host:9200/test-3/log/1?pretty" -H 'Content-Type: application/json' -d '{ "user": "mike"}'
curl -X PUT "my.elasticsearch.host:9200/test-3/log/2?pretty" -H 'Content-Type: application/json' -d '{ "user": "freddy"}'

However, that does not seem to work. When I query, I don't see the "user" in the output anywhere.
What am I missing?

[jcaballero (Jose)]

OK... replying to myself. This template seems to do the trick for new documents.

curl -X PUT "my.elasticsearch.host:9200/_template/template_1" -H 'Content-Type: application/json' -d'
{
  "template": "test*",
  "mappings": {
     "log" : {
        "properties": {
          "user": {
            "type": "keyword"
        }
       }
    }
  }
}
'

Still don't know how to apply it to existing documents already stored. Maybe that is not possible.

[Mark_Harwood]

Not possible but the “reindex” api will allow you to copy the old docs to an index with the correct mapping

[jcaballero (Jose)]

thanks !!