Upgrade Notes:

• Upgrading from 0.18 requires issuing a full flush of all the indices in the cluster (curl host:9200/_flush) before shutting down the cluster, with no indexing operations happening after the flush.
• The local gateway state structure has changed, a backup of the state files is created when upgrading, they can then be used to downgrade back to 0.18. Don’t downgrade without using them.

Enhancements:

• Use bloom filter when flushing (applying deletes) (#2058)
• “index_analyzer” and “search_analyzer” should override “analyzer” (#2052)

Bug fixes:

• deb package fails to start elasticsearch (#2053)
• Stored Compression: failure to fetch document in certain cases (read failure, index compression works) (#2055)