The IK Analysis plugin integrates Lucene IK analyzer into elasticsearch, support customized dictionary.

https://github.com/medcl/elasticsearch-analysis-ik

This Pinyin Analysis plugin is used to do conversion between Chinese characters and Pinyin.

https://github.com/medcl/elasticsearch-analysis-pinyin

Monitoring and Management Web Application for ElasticSearch instances and clusters.

https://github.com/ElasticHQ/elasticsearch-HQ

Search Guard SSL Plugin

https://docs.search-guard.com/latest/search-guard-versions

the ICU libraries, including better analysis of Asian languages, Unicode normalization, Unicode-aware case folding, collation support, and transliteration.

https://www.elastic.co/guide/en/elasticsearch/plugins/current/analysis-icu.html

The ingest attachment plugin lets Elasticsearch extract file attachments in common formats (such as PPT, XLS, and PDF) by using the Apache text extraction library Tika.

https://www.elastic.co/guide/en/elasticsearch/plugins/current/ingest-attachment.html