* master:
Add get field mappings to High Level REST API Client (#31423)
[DOCS] Updates Watcher examples for code testing (#31152)
TEST: Add bwc recovery tests with synced-flush index
[DOCS] Move sql to docs (#31474)
[DOCS] Move monitoring to docs folder (#31477)
Core: Combine doExecute methods in TransportAction (#31517)
IndexShard should not return null stats (#31528)
fix repository update with the same settings but different type (#31458)
Fix Mockito trying to mock IOException that isn't thrown by method (#31433) (#31527)
Node selector per client rather than per request (#31471)
Core: Combine messageRecieved methods in TransportRequestHandler (#31519)
Upgrade to Lucene 7.4.0. (#31529)
[ML] Add ML filter update API (#31437)
Allow multiple unicast host providers (#31509)
Avoid deprecation warning when running the ML datafeed extractor. (#31463)
REST high-level client: add simulate pipeline API (#31158)
Get Mapping API to honour allow_no_indices and ignore_unavailable (#31507)
[PkiRealm] Invalidate cache on role mappings change (#31510)
[Security] Check auth scheme case insensitively (#31490)
In NumberFieldType equals and hashCode, make sure that NumberType is taken into account. (#31514)
[DOCS] Fix REST tests in SQL docs
[DOCS] Add code snippet testing in more ML APIs (#31339)
Core: Remove ThreadPool from base TransportAction (#31492)
[DOCS] Remove fixed file from build.gradle
Rename createNewTranslog to fileBasedRecovery (#31508)
Test: Skip assertion on windows
[DOCS] Creates field and document level security overview (#30937)
[DOCS] Significantly improve SQL docs
[DOCS] Move migration APIs to docs (#31473)
Core: Convert TransportAction.execute uses to client calls (#31487)
Return transport addresses from UnicastHostsProvider (#31426)
Ensure local addresses aren't null (#31440)
Remove unused generic type for client execute method (#31444)
Introduce http and tcp server channels (#31446)
08ee9b67c5