碎片令牌过滤器错误“ illegal_argument_exception”

Question

我正在使用Elasticsearch在轨道上使用红宝石。我使用 Elastic::Model::JobPosting.recreate_index!进行索引。我得到的错误：

{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"In Shingle TokenFilter the difference between max_shingle_size and min_shingle_size (and +1 if outputting unigrams) must be less than or equal to: [3] but was [4].

但是在进一步检查带状疱疹值时，我发现：

min_shingle_size: 2,
max_shingle_size: 5,

所以它们之间的区别是“ 3”，但是输出为何变成“ 4”。我似乎无法理解其原因

我的模块/弹性/实用程序代码是：

module ::Elastic::Utils

  def self.suggestion_field
    {
        analyzer: :name_analyzer,
        type: "text",

        fields:   {
            :raw      => {type: "keyword", index: true}
        }
    }
  end

  def self.optimized_suggestion_field
    {
      analyzer: :suggest_analyzer,
      type: "text"
    }
  end

  def self.optimized_settings
    {
      index: {
        number_of_shards: 2,
        number_of_replicas: 1
      },

      analysis: {
        analyzer:    {
          suggest_analyzer: {
            tokenizer: 'keyword',
            type: 'custom',
            filter: %w(suggest_filter)
          }
        },
        filter: {
          suggest_filter: {
            type:     'edgeNGram',
            max_gram: 40,
            min_gram: 1
          }
        },
      }
    }
  end

  def self.common_settings
    {
      index: {
        number_of_shards: 2,
        number_of_replicas: 1
      },

      analysis: {
        analyzer:    {
          name_analyzer: {
            tokenizer: 'whitespace',
            type:      'custom',
            filter:    %w(lowercase multi_words name_filter)
          },
          lower_keyword: {
            tokenizer: 'keyword',
            type:      'custom',
            filter:    ['lowercase']
          },
        },
        filter: {
          multi_words: {
            type:             'shingle',
            min_shingle_size: 2,
            max_shingle_size: 5
          },
          name_filter: {
            type:     'edgeNGram',
            max_gram: 40,
            min_gram: 1
          }
        },
      }
    }
  end

  def self.normalized_terms(name)
    terms = []
    terms = name.split(/\W+/) if name.present?
    normalized_terms = []
    norm_term  = ''
    terms.reverse.each do |term|
      norm_term = "#{term}#{norm_term}"
      normalized_terms << norm_term
    end
    normalized_terms.reverse
  end

  def self.normalize(name)
    return nil if name.blank?
    name.downcase.gsub(/[^[:alnum:]]/, ' ').
    gsub(' and ', ' ').gsub(' of ', ' ').gsub(' in ', ' ').
    gsub('engineering', 'engg').gsub('technology', 'tech').
    gsub('bachelor ', 'b ').gsub('master ', 'm ').
    squish
  end

end