ElasticSearch highlights results repeats snippets

Question

I'm using FOSElasticaBundle to index ES documents with this config:

index:
analysis:
    analyzer:
        custom_analyzer:
            type:           custom
            tokenizer:      nGram
            filter:         [stopwords, asciifolding ,lowercase, snowball, elision, worddelimiter]
        custom_search_analyzer:
            type:           custom
            tokenizer:      standard
            filter:         [stopwords, asciifolding ,lowercase, snowball, elision, worddelimiter]
    tokenizer:
        nGram:
            type:           nGram
            min_gram:       2
            max_gram:       20
    filter:
        snowball:
            type:           snowball
            language:       French
        elision:
            type:           elision
            articles:       [l, m, t, qu, n, s, j, d]
        stopwords:
            type:           stop
            stopwords:      [_french_]
            ignore_case:    true
        worddelimiter:
            type:           word_delimiter
    types:
        document:
            indexable_callback:         'isIndexable'
            mappings:
                title:
                    boost:              3
                    index_analyzer:     custom_analyzer
                    search_analyzer:    custom_search_analyzer
                summary:
                    boost:              2
                    index_analyzer:     custom_analyzer
                    search_analyzer:    custom_search_analyzer
                description:
                    boost:              1
                    index_analyzer:     custom_analyzer
                    search_analyzer:    custom_search_analyzer

I'm trying to use the highlight functionnality of ES, here is an request example:

{
  "query":
  {
    "bool":
    {
      "must":
      [
        {
          "query_string": {
            "query": "blonde",
            "default_field": "_all"
          }
        }
      ]
    }
  },
  "highlight": {
    "fields": {
      "*": {  }
    }
  }
}

Gives the result:

"highlight": {

    "title": [
        "Une jeune personne b<em>personne blonde se</em><em>ersonne blonde se te</em><em>blonde se tenait e</em>n partie double, elle avait choisi."
    ]

}

The original content is Une jeune personne blonde se tenait en partie double, elle avait choisi.

I've done some tests with different analyser configuration + reindexation of the documents, but I never got a good highlight of all the snippet: sometimes, one is highlighted, not the others, sometimes, none, etc.

What's the matter between the analysers and the highlights process? What's wrong with my config?

Post the complete mapping of that index. – Andrei Stefan Feb 27 '15 at 19:14 — Andrei Stefan, Feb 27 '15 at 19:14
Thanks, here is the full config – Lionel Mar 02 '15 at 09:03 — Lionel, Mar 02 '15 at 09:03

score 0 · Answer 1 · edited May 23 '17 at 11:46

Notice you can adjust your highlighting params, check with the config above:

"highlight": {
        "number_of_fragments": 5,
        "type": "plain",
        "fields": {
            "*": {
                "fragment_size": 100
            }
        }
    }

There is another link here which could help you about strange results : Curious behaviour of fragment_size in elasticsearch highlighting

ElasticSearch highlights results repeats snippets

1 Answers1