Upgrade Notes:

• Upgrading from 0.19 requires a full cluster restart.

Breaking Changes:

• Shared Gateway has been deprecated (2459)
• Snappy compression has been deprecated (2458)
• Plugins Installer: Allow to download plugins from download.elasticsearch.org (#2507)

New features:

• Allow highlighting on wildcard fields.. ie, comment_* (#2396)

Enhancements:

• Nested query should support explain. (#2503)
• Add scoring support to has_child and has_parent queries (#2502)
• match_all filter with empty array (instead of obj) fires exception when used with facets (#2493)
• Update settings: Allow to dynamically update thread pool settings (#2509)

Bug fixes:

• top_children query fails with dfs_query_* searchtype and some queries (#2501)
• ArrayOutOfBoundException when using top_children in a must not clause. (#2500)
• Search failures are not serialized correctly in MultiSearchResponse (#2498)
• ShardSearchFailure handling of exception does not take actual into account for status (#2495)
• Mlt api fails to work when routing isn’t id based. (#2489)
• First indexing of a dynamic boolean field can cause it not to be indexed correctly (#2487)
• : query not working (#2486)