> For the complete documentation index, see [llms.txt](https://xiaoxiami.gitbook.io/elasticsearch/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xiaoxiami.gitbook.io/elasticsearch/bi-ji.md).

# 笔记

- [1.x 升级 2.x](https://xiaoxiami.gitbook.io/elasticsearch/bi-ji/1x-sheng-ji-2-x.md)