为 Rails 模型创建 Elasticsearch 索引时如何修复“非法参数异常”？

Question

I'm trying to integrate Elasticsearch in my rails application. The problem comes when I try to do an import on my model. Video.__elasticsearch__.import.

So, in rails console, I ran Video.__elasticsearch__.import . I get this error: myflix_development does not exist to be imported into. Use create_index! or the :force option to create it.

I then ran Video.__elasticsearch__.create_index! and Video.__elasticsearch__.create_index!(force: true) and they both returned the same error of illegal argument exception:

 PUT http://localhost:9200/myflix_development [status:400, request:0.027s, query:N/A]
2019-06-08 11:18:29 +0800: > {"settings":{},"mappings":{"_doc":{"properties":{}}}}
2019-06-08 11:18:29 +0800: < {"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"The mapping definition cannot be nested under a type [_doc] unless include_type_name is set to true."}],"type":"illegal_argument_exception","reason":"The mapping definition cannot be nested under a type [_doc] unless include_type_name is set to true."},"status":400}

I understand that I am supposed to create an elasticsearch index when I try to do an import but I'm getting this illegal argument exception which I am puzzled about

This is what I've done to set things up:

1) Included the gems in my gemfile:

gem 'elasticsearch-model'
gem 'elasticsearch-rails'

2) Included an initializer: app/config/initializers/elasticsearch.rb

Elasticsearch::Model.client =
  if Rails.env.staging? || Rails.env.production?
    Elasticsearch::Client.new url: ENV['SEARCHBOX_URL']
  elsif Rails.env.development?
    Elasticsearch::Client.new log: true
  else
    Elasticsearch::Client.new
  end

3) Included elasticsearch in my Video model

class Video < ActiveRecord::Base
  include Elasticsearch::Model
  index_name ["myflix", Rails.env].join("_")
  ...
end

4) Gemfile.lock

 elasticsearch (7.1.0)
      elasticsearch-api (= 7.1.0)
      elasticsearch-transport (= 7.1.0)
    elasticsearch-api (7.1.0)
      multi_json
    elasticsearch-model (6.0.0)
      activesupport (> 3)
      elasticsearch (> 1)
      hashie
    elasticsearch-rails (6.0.0)
    elasticsearch-transport (7.1.0)
      faraday
      multi_json

Any help will be appreciated!

Edit 1) Attempted to do a manual mapping in my model

class Video < ActiveRecord::Base
    include Elasticsearch::Model

    settings index: { number_of_shards: 1 } do
    mappings dynamic: 'false' do
      indexes :title, type: 'text'
      indexes :description, type: 'text'
    end
  end
...
end

Answer 1

You can explicitly define the document type that elasticsearch-model passes to Elasticsearch by setting document_type . For instance:

class Video < ActiveRecord::Base
  include Elasticsearch::Model
  index_name ["myflix", Rails.env].join("_")
  document_type "video"
  ...
end

What name you use is arbitrary. As long as it's not _doc , you shouldn't run into this error on v7 and up.

Answer 2

From the error you have, I think you are using elasticsearch 7. The type _doc is specified in your index query but types are deprecated since es7 .

You can try to update your elasticsearch library to match es7 or as suggested in the error message, you can use the parameter include_type_name in the mapping.

Answer 3

The "illegal argument exception" is getting occurred because ElasticSearch engine is failing to analyze a reserved keyword. is considered the root field inside the mapping section.Reform the request as below by excluding the "_doc" keyword :

PUT {INDEX_NAME} {"settings":{},"mappings":{"properties":{}}}}