[Doc] ignore_above default value is wrong.

[AlJuan]

Elasticsearch version (bin/elasticsearch --version): Version: 6.1.1, Build: bd92e7f/2017-12-17T20:23:25.338Z, JVM: 1.8.0_151

Plugins installed: []

JVM version (java -version): openjdk version "1.8.0_151"
OpenJDK Runtime Environment (build 1.8.0_151-8u151-b12-0ubuntu0.16.04.2-b12)
OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)

OS version (uname -a if on a Unix-like system): Linux pmitn009906 4.4.0-41-generic #61-Ubuntu SMP Tue Sep 27 17:27:48 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

Description of the problem including expected versus actual behavior: When i create a new index, the keyword mapping ignore_above defaults to 256. The doc says the default is 2147483647.

Steps to reproduce:

Please include a minimal but complete recreation of the problem, including
(e.g.) index creation, mappings, settings, query etc. The easier you make for
us to reproduce it, the more likely that somebody will take the time to look at it.

1. First create an index:
   curl -XPUT 'localhost:9200/test?pretty' -H 'Content-Type: application/json' -d' { "settings" : { "index" : { } } }'
2. Then insert some value:
   curl -XPUT 'localhost:9200/test/testType/1?pretty' -H 'Content-Type: application/json' -d' { "user" : "kimchy", "post_date" : "2009-11-15T14:12:12", "message" : "trying out Elasticsearch" } '
3. When I get the mapping info for that index (curl -XGET 'localhost:9200/test/_mapping/testType?pretty') it returns:

{
  "test" : {
    "mappings" : {
      "testType" : {
        "properties" : {
          "message" : {
            "type" : "text",
            "fields" : {
              "keyword" : {
                "type" : "keyword",
                "ignore_above" : 256
              }
            }
          },
          "post_date" : {
            "type" : "date"
          },
          "user" : {
            "type" : "text",
            "fields" : {
              "keyword" : {
                "type" : "keyword",
                "ignore_above" : 256
              }
            }
          }
        }
      }
    }
  }
}

In addition to this, there is a blog post by Adrien Grand saying that the default ignore_above value is 256.

[DaveCTurner]

I think the change proposed in #27991 seemed like the right thing to do, and I'm not sure why it was closed. WDYT @jpountz?

[jpountz]

I guess the confusion comes from the fact that there are multiple defaults:

• ignore_above has a default value of 2^31-1 on keyword fields. If you create a keyword field without providing an explicit value for ignore_above, this is the value that will be taken into account.
• The default dynamic mappings for strings set up a keyword field that has ignore_above: 256.

By the way, the reason why ignore_above is explicit on the GET _mapping call is because it doesn't have the default value. Otherwise it would have been omitted.

[AlJuan]

Like @jpountz said, I created an index:

curl -XPUT 'localhost:9200/test?pretty' -H 'Content-Type: application/json' -d'
{
  "mappings": {
    "testType": { 
      "properties": { 
        "someField":    { "type": "keyword"  }        
      }
    }
  }
}
'

Now the ignore_above field is not explicit on the GET _mapping. The values I inserted on the someField field are indexed, even if they are longer than 256.

Should I close this issue?

[jiangjunjian]

org.springframework.dao.InvalidDataAccessApiUsageException: Document contains at least one immense term in field="detailContent" (whose UTF8 encoding is longer than the max length 32766), all of which were skipped. Please correct the analyzer to not produce such terms.