> For the complete documentation index, see [llms.txt](https://liuzhenglaichn.gitbook.io/system-design/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://liuzhenglaichn.gitbook.io/system-design/todo-1/elastic-search.md).

# Elastic Search

Distributed Search and Analysis Engine and NoSQL database

Based on Lucene.

Features:

1. RestFul API for searching and indexing
2. Free text searching
3. Built-in sharding, indexing, replication
4. Key-Value store and field filtering and searching
5. Machine learning searching
6. Elastic stack for big data analyzing