…25195)

This prevents possible race conditions between the Elasticsearch JVM and
plugin native controller processes that can cause the Elasticsearch shutdown
to hang.  The problem can happen when the JVM and the controller process
receive a SIGTERM at almost the same time.

(There's an assumption here that Elasticsearch will continue to use other
mechanisms to kill native controller processes.)

…25195)

This prevents possible race conditions between the Elasticsearch JVM and
plugin native controller processes that can cause the Elasticsearch shutdown
to hang.  The problem can happen when the JVM and the controller process
receive a SIGTERM at almost the same time.

(There's an assumption here that Elasticsearch will continue to use other
mechanisms to kill native controller processes.)

…25195)

This prevents possible race conditions between the Elasticsearch JVM and
plugin native controller processes that can cause the Elasticsearch shutdown
to hang.  The problem can happen when the JVM and the controller process
receive a SIGTERM at almost the same time.

(There's an assumption here that Elasticsearch will continue to use other
mechanisms to kill native controller processes.)

* master: (27 commits)
  Refactor TransportShardBulkAction.executeUpdateRequest and add tests
  Make sure range queries are correctly profiled. (elastic#25108)
  Test: allow setting socket timeout for rest client (elastic#25221)
  Migration docs for elastic#25080 (elastic#25218)
  Remove `discovery.type` BWC layer from the EC2/Azure/GCE plugins elastic#25080
  When stopping via systemd only kill the JVM, not its control group (elastic#25195)
  Remove PrefixAnalyzer, because it is no longer used.
  Internal: Remove Strings.cleanPath (elastic#25209)
  Docs: Add note about which secure settings are valid (elastic#25212)
  Indices.rollover/10_basic should refresh to make the doc visible in lucene stats
  Port support for commercial GeoIP2 databases from Logstash. (elastic#24889)
  [DOCS] Add ML node to node.asciidoc (elastic#24495)
  expose simple pattern tokenizers (elastic#25159)
  Test: add setting to change request timeout for rest client (elastic#25201)
  Fix secure repository-hdfs tests on JDK 9
  Add target_field parameter to gsub, join, lowercase, sort, split, trim, uppercase (elastic#24133)
  Add Cross Cluster Search support for scroll searches (elastic#25094)
  Adapt skip version in rest-api-spec/test/indices.rollover/20_max_doc_condition.yml
  Rollover max docs should only count primaries (elastic#24977)
  Add remote cluster infrastructure to fetch discovery nodes. (elastic#25123)
  ...

* master: (44 commits)
  Upgrade icu4j for the ICU analysis plugin to 59.1 (elastic#25243)
  move assertBusy to use CheckException (elastic#25246)
  Use SPI in High Level Rest Client to load XContent parsers (elastic#25098)
  [TEST] test that low level REST client leaves path untouched (elastic#25193)
  Speed up PK lookups at index time. (elastic#19856)
  [Docs] Fix documentation for percentiles bucket aggregation (elastic#25229)
  Upgrade to lucene-7.0.0-snapshot-92b1783. (elastic#25222)
  Build: Add master flag for disabling bwc tests (elastic#25230)
  Scripting: Rename SearchScript.needsScores to needs_score (elastic#25235)
  Support script context stateful factory in Painless. (elastic#25233)
  FastVectorHighlighter should not cache the field query globally (elastic#25197)
  Remove QUERY_AND_FETCH BWC for pre-5.3.0 nodes (elastic#25223)
  Add more missing AggregationBuilder getters (elastic#25198)
  Extract the snapshot/restore full cluster restart tests from the translog full cluster restart tests (elastic#25204)
  Refactor TransportShardBulkAction.executeUpdateRequest and add tests
  Make sure range queries are correctly profiled. (elastic#25108)
  Test: allow setting socket timeout for rest client (elastic#25221)
  Migration docs for elastic#25080 (elastic#25218)
  Remove `discovery.type` BWC layer from the EC2/Azure/GCE plugins elastic#25080
  When stopping via systemd only kill the JVM, not its control group (elastic#25195)
  ...