- 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.
- msearch should accept a leading n (#1736)
- Date Histogram Facet: Add
- Flush: Add a specific thread pool for flush operations (scheduled and API) (#1734)
- Translog Flush: When disabling flush and enabling it again, scheduled flush stops executing (#1727)
- Real time get on a stored _size field does not return its value (#1724)
- query never returns (#1725)
- Orderly shutdown with unicast discovery might cause the shutdown node to still be part of the election process (#1740)
- NullPointerException when asking for null valued json field when fetching search request (#1749)
- Multi level parent/child mapping and search fails (#1751)
Also see release notes for: