Log Message:
elasticsearch 5.5.2
======================================================================

=== Bug fixes

Aggregations::
- Fixes array out of bounds for value count agg

Core::
- Release operation permit on thread-pool rejection

Inner Hits::
- Fix inner hits to work with queries wrapped in an indices query
- When fetching nested inner hits only access stored fields when needed

Logging::
- Declare XContent deprecation logger as static

Query DSL::
- Parse "*" in query_string_query as MatchAllDocsQuery

elasticsearch 5.5.1
======================================================================

=== Bug fixes

Aliases::
- mget with an alias shouldn't ignore alias routing

Engine::
- Engine - Do not store operations that are not index into lucene in the
  translog (5.x only)

Internal::
- Fix BytesReferenceStreamInput#skip with offset

Packaging::
- Stop disabling explicit GC
- Avoid failing install if system-sysctl is masked
- Get short path name for native controllers

Query DSL::
- WrapperQueryBuilder should also rewrite the parsed query

elasticsearch 5.5.0
======================================================================

=== Breaking changes

Plugins::
- Remove hidden file leniency from spawner

Settings::
- Remove support for default settings

=== Breaking Java changes

Aggregations::
- Remove the unused SignificantTerms.compareTerm() method
- Make SignificantTerms.Bucket an interface rather than an abstract
  class
- Make Terms.Bucket an interface rather than an abstract class

Plugin Delete By Query::
- Move DeleteByQuery and Reindex requests into core

=== Deprecations

Index APIs::
- Deprecated use of + in index expressions

Packaging::
- Add deprecation warnings for $ES_USER and $ES_GROUP

Plugin Repository S3::
- S3 Repository: Deprecate remaining `repositories.s3.*` settings

REST::
- Add deprecation logging for comma-separated feature parsing

Scripting::
- Scripting: Deprecate native scripts
- Scripting: Deprecate index lookup
- Deprecate Fine Grain Settings for Scripts
- Scripting: Deprecate file script settings
- Scripting: Deprecate file scripts

Settings::
- Settings: Update settings deprecation from yml to yaml
- Deprecate settings in .yml and .json

Tribe Node::
- Deprecate tribe service

=== New features

Mapping::
- Add new ip_range field type

Plugin Analysis ICU::
- Add ICUCollationFieldMapper

=== Enhancements

Aggregations::
- Add superset size to Significant Term REST response
- Add document count to Matrix Stats aggregation response
-  Share XContent rendering code in significant terms aggregations
- Add `count` to rest output of `geo_centroid`
- Allow scripted metric agg to access `_score`

Aliases::
- Handle multiple aliases in _cat/aliases api

Circuit Breakers::
- Closing a ReleasableBytesStreamOutput closes the underlying BigArray

Cluster::
- Add a cluster block that allows to delete indices that are read-only
- Extract a common base class to allow services to listen to remote
  cluster config updates

Core::
- Explicitly reject duplicate data paths
- Use SPI in High Level Rest Client to load XContent parsers
- Improve bootstrap checks error messages
- Regex upgrades
- Detect remnants of path.data/default.path.data bug

Engine::
- Add refresh stats tracking for realtime get
- Engine: store maxUnsafeAutoIdTimestamp in commit

Exceptions::
- IllegalStateException: Only duplicated jar instead of classpath

Index APIs::
- Open and close index to honour allow_no_indices option

Ingest::
- add `exclude_keys` option to KeyValueProcessor

Inner Hits::
- Reuse inner hit query weight

Internal::
- "shard started" should show index and shard ID
- Add the ability to set eager_global_ordinals in the new parent-join
  field
- Add assertions enabled helper
- Add cross cluster support to `_field_caps`
- Log JVM arguments on startup
- Preserve cluster alias throughout search execution to lookup nodes by
  cluster and ID
- Move RemoteClusterService into TransportService
- Enum related performance additions.

Java API::
- Always Accumulate Transport Exceptions

Java High Level REST Client::
- Add doc_count to ParsedMatrixStats
- Add fromXContent method to ClearScrollResponse
- ClearScrollRequest to implement ToXContentObject
- SearchScrollRequest to implement ToXContentObject
- Backport aggs parsers for high level REST Client
- Add utility method to parse named XContent objects with typed prefix

Logging::
- Warn on not enough masters during election

Mapping::
- Do not index `_type` when there is at most one type.
- Only allow one type on 6.0 indices
- token_count type : add an option to count tokens (fix #23227)

Network::
- Disable the Netty recycler in the client
- Remove Netty logging hack
- Set available processors for Netty

Packaging::
- Set number of processes in systemd unit file

Plugin Lang Painless::
- Optimize instance creation in LambdaBootstrap
- Allow painless to load stored fields

Plugin Repository GCS::
- GCS Repository: Add secure storage of credentials

Plugins::
- Add purge option to remove plugin CLI
- Move ReindexAction class to core
- Plugins: Add support for platform specific plugins

REST::
- Make ObjectParser support string to boolean conversion
- Allow passing single scrollID in clear scroll API body

Scripting::
- Add Ability to Specify No Types/Contexts Allowed For Scripts
- Add New Security Script Settings

Search::
- Eliminate array access in tight loops when profiling is enabled.
- Support Multiple Inner Hits on a Field Collapse Request
- Expand cross cluster search indices for search requests to the
  concrete index or to it's aliases
- Remove leniency when merging fetched hits in a search response phase

Search Templates::
- Add max concurrent searches to multi template search

Settings::
- Emit settings deprecation logging at most once

Snapshot/Restore::
- Improves snapshot logging and snapshot deletion error handling
- Enhances get snapshots API to allow retrieving repository index only
- Ensure every repository has an incompatible-snapshots blob
- Change snapshot status error to use generic SnapshotException

Stats::
- Show JVM arguments

Suggesters::
- Provide informative error message in case of unknown suggestion
  context.
- Allow different data types for category in Context suggester

Upgrade API::
- Allow plugins to upgrade templates and index metadata on startup

=== Bug fixes

Aggregations::
- Terms aggregation should remap global ordinal buckets when a
  sub-aggregator is used to sort the terms
- Correctly set doc_count when MovAvg "predicts" values on existing
  buckets
- InternalPercentilesBucket should not rely on ordered percents array
- Align behavior HDR percentiles iterator with percentile() method
- DateHistogram: Fix `extended_bounds` with `offset`
- Fix ArrayIndexOutOfBoundsException when no ranges are specified in the
  query

Aliases::
- GET aliases should 404 if aliases are missing

Allocation::
- Discard stale node responses from async shard fetching

Analysis::
- PatternAnalyzer should lowercase wildcard queries when `lowercase` is
  true.

Bulk::
- Reject empty IDs

Cache::
- fix bug of weight computation

Circuit Breakers::
- Checks the circuit breaker before allocating bytes for a new big array

Core::
- Fix cache expire after access
- Check for default.path.data included in path.data

Geo::
- Fix GeoPoint FieldStats ternary logic bug
- Fix GeoDistance Ordinal for BWC

Highlighting::
- Higlighters: Fix MultiPhrasePrefixQuery rewriting

Index APIs::
- Rollover max docs should only count primaries
- Fix legacy GeoPointField decoding in FieldStats
- Validates updated settings on closed indices
- Fixes restore of a shrunken index when initial recovery node is gone

Ingest::
- fix grok's pattern parsing to validate pattern names in expression
- Fix floating-point error when DateProcessor parses UNIX
- add option for _ingest.timestamp to use new ZonedDateTime (5.x
  backport)

Inner Hits::
- Fix Source filtering in new field collapsing feature

Internal::
- Fix race condition in RemoteClusterConnection node supplier
- Initialise empty lists in BaseTaskResponse constructor
- Extract a common base class for scroll executions
- Ensure remote cluster is connected before fetching `_field_caps`
- Obey lock order if working with store to get metadata snapshots
- Remove `_UNRELEASED` from Version constants for released versions
- Fix `_field_caps` serialization in order to support cross cluster
  search
- Avoid race when shutting down controller processes
- Fix NPE if field caps request has a field that exists not in all
  indices

More Like This::
- Pass over _routing value with more_like_this items to be retrieved

Nested Docs::
- In case of a single type the _id field should be added to the nested
  document instead of _uid field

Network::
- Ensure pending transport handlers are invoked for all channel failures
- Notify onConnectionClosed rather than onNodeDisconnect to prune
  transport handlers
- SniffNodesSampler should close connection after handling responses

Packaging::
- When stopping via systemd only kill the JVM, not its control group
- Handle parentheses in batch file path

Percolator::
- Fix range queries with date range based on current time in percolator
  queries.
- For legacy indices rewrite percolator query upon percolation time
- Fix memory leak when percolator uses bitset or field data cache

Plugin Lang Painless::
- painless: Fix method references to ctor with the new LambdaBootstrap
  and cleanup code
- Fix Painless Lambdas for Java 9

Plugins::
- X-Pack plugin download fails on Windows desktop
- Fix plugin installation permissions
- Fix delete of plugin directory on remove plugin
- Use a marker file when removing a plugin
- Remove hidden file leniency from plugin service

Query DSL::
- Thread falls into infinite loop when processing Indices query

REST::
- Fix handling of exceptions thrown on HEAD requests
- Fixed NPEs caused by requests without content.
- Fix get mappings HEAD requests

Recovery::
- Provide target allocation id as part of start recovery request

Reindex API::
- Reindex: don't duplicate _source parameter
- Add qa module that tests reindex-from-remote against pre-5.0 versions
  of Elasticsearch

Scroll::
- Fix single shard scroll within a cluster with nodes in version `>=
  5.3` and `<= 5.3`

Search::
- Adds check for negative search request size
- Do not search locally if remote index pattern resolves to no indices
- Make sure range queries are correctly profiled.
- Compute the took time of the query after the expand phase of field
  collapsing
- Fix RangeFieldMapper rangeQuery to properly handle relations
- Fix ExpandSearchPhase when response contains no hits
- Include all aliases including non-filtering in  `_search_shards`
  response
- Cross Cluster Search: propagate original indices per cluster

Search Templates::
- No longer add illegal content type option to stored search templates

Settings::
- Keystore CLI should use the AddFileKeyStoreCommand for files
- Settings: Fix setting groups to include secure settings
- Allow resetting settings that use an IP validator
- Do not set path.data in environment if not set

Snapshot/Restore::
- Output all empty snapshot info fields if in verbose mode
- Remove redundant and broken MD5 checksum from repository-s3
- Consolidates the logic for cleaning up snapshots on master election
- Removes completed snapshot from cluster state on master change
- Fix inefficient (worst case exponential) loading of snapshot
  repository
- Fixes maintaining the shards a snapshot is waiting on

Stats::
- _nodes/stats should not fail due to concurrent AlreadyClosedException
- Avoid double decrement on current query counter

Suggesters::
- Fix context suggester to read values from keyword type field

Task Manager::
- Task Management: Make TaskInfo parsing forwards compatible

=== Regressions

Highlighting::
- Fix Fast Vector Highlighter NPE on match phrase prefix

=== Upgrades

Core::
- Upgrade to Lucene 6.5.1

Network::
- Upgrade to Netty 4.1.11.Final
- Upgrade Netty to 4.1.10.Final