- Upgrading from 0.19 requires a full cluster restart.
- Shared Gateway has been deprecated (2459)
- Snappy compression has been deprecated (2458)
- Plugins Installer: Allow to download plugins from download.elasticsearch.org (#2507)
- Sometimes MapperParsingException and sometimes not (#2354)
- Deb package wrongly includes additional lucene libraries (#2599)
- Support MultiPhrasePrefix (MatchQuery.Type.PHRASE_PREFIX) in Highlighters (#2596)
- Indexes created from index request might not replica initial doc to replica (#2594)