Raudikko Analysis for Elasticsearch

The Raudikko Analysis plugin provides Finnish language analysis using Raudikko.

Supported versions

Since 0.2, the plugin is built against Elasticsearch's stable plugin API, so a single package works with the Elasticsearch version it was built for and all later versions, instead of needing a separate build per Elasticsearch version.

Plugin version	Raudikko version	Elasticsearch versions
0.2	0.1.4	9.3.0 and later
0.1.2	0.1.2	8.x.x
0.1.1	0.1.1	7.x.x
0.1	0.1.1	7.3.2, 7.10.0

Need a version for Elasticsearch < 9.3.0? Check the older releases, which still ship per-ES-version packages.

Looking for a version for OpenSearch? Check out opensearch-analysis-raudikko.

Installing

Download the plugin zip from the releases page and install it with:

bin/elasticsearch-plugin install https://github.com/EvidentSolutions/elasticsearch-analysis-raudikko/releases/download/v0.2/elasticsearch-analysis-raudikko-0.2.zip

Docker

Building the plugin and running it with Docker:

./gradlew build
cd etc
docker compose build
docker compose up

Elasticsearch should then be running and available at http://localhost:9200. Note that docker compose up is required to publish the port — docker compose run does not publish ports unless you add --service-ports.

To build against a different (newer) Elasticsearch version, override the version on both the Gradle build and the Docker build:

./gradlew build -DelasticsearchVersion=9.4.0
docker compose build --build-arg "ES_VERSION=9.4.0"

Verify installation

After installing the plugin, you can quickly verify that it works by executing:

curl -XGET 'localhost:9200/_analyze' -H 'Content-Type: application/json' -d '
{
  "tokenizer" : "finnish",
  "filter" : [{"type": "raudikko"}],
  "text" : "Testataan raudikon analyysiä tällä tavalla yksinkertaisesti."
}'

If this works without error messages, you can proceed to configure the plugin index.

Configuring

Include finnish tokenizer and raudikko filter in your analyzer, for example:

{
  "index": {
    "analysis": {
      "analyzer": {
        "default": {
          "tokenizer": "finnish",
          "filter": ["lowercase", "raudikkoFilter"]
        }
      },
      "filter": {
        "raudikkoFilter": {
          "type": "raudikko"
        }
      }
    }
  }
}

You can use the following filter options to customize the behaviour of the filter:

Parameter	Default value	Description
analyzeAll	true	Use all analysis possibilities or just the first
splitCompoundWords	false	Split analysed compound words to its parts
minimumWordSize	3	minimum length of words to analyze
maximumWordSize	100	maximum length of words to analyze
analysisCacheSize	1024	number of analysis results to cache

Compatibility with elasticsearch-analysis-voikko

This plugin supersedes elasticsearch-analysis-voikko and is fully compatible with it (it provides a filter named voikko as a compatibility measure). Therefore, you can remove the old plugin from your Elasticsearch installation and replace it with this plugin without having to reindex anything. Just make sure to uninstall the old plugin bin/elasticsearch-plugin remove elasticsearch-analysis-voikko when installing this one in place.

License and copyright

Copyright (C) 2021-2026 Evident Solutions Oy

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.