[[release-notes-6.0.0-alpha2]]
== 6.0.0-alpha2 Release Notes

Also see <<breaking-changes-6.0>>.

[[breaking-6.0.0-alpha2]]
[float]
=== Breaking changes

CRUD::
* Deleting a document from a non-existing index creates the indexIf the index does not exist, delete document will not auto create it {pull}24518[#24518] (issue: {issue}15425[#15425])

Plugin Analysis ICU::
* Upgrade icu4j to latest version {pull}24821[#24821]

Plugin Repository S3::
* Remove deprecated S3 settings {pull}24445[#24445]

Scripting::
* Remove script access to term statistics {pull}19462[#19462] (issue: {issue}19359[#19359])



[[breaking-java-6.0.0-alpha2]]
[float]
=== Breaking Java changes

Aggregations::
* Make Terms.Bucket an interface rather than an abstract class {pull}24492[#24492]
* Compound order for histogram aggregations  {pull}22343[#22343] (issues: {issue}14771[#14771], {issue}20003[#20003], {issue}23613[#23613])

Plugins::
* Drop name from TokenizerFactory {pull}24869[#24869]



[[deprecation-6.0.0-alpha2]]
[float]
=== Deprecations

Settings::
* Deprecate settings in .yml and .json {pull}24059[#24059] (issue: {issue}19391[#19391])



[[feature-6.0.0-alpha2]]
[float]
=== New features

Aggregations::
* SignificantText aggregation - like significant_terms, but for text {pull}24432[#24432] (issue: {issue}23674[#23674])

Internal::
* Automatically adjust search threadpool queue_size {pull}23884[#23884] (issue: {issue}3890[#3890])

Mapping::
* Add new ip_range field type {pull}24433[#24433]

Plugin Analysis ICU::
* Add ICUCollationFieldMapper {pull}24126[#24126]



[[enhancement-6.0.0-alpha2]]
[float]
=== Enhancements

Core::
* Improve bootstrap checks error messages {pull}24548[#24548]

Engine::
* Move the IndexDeletionPolicy to be engine internal {pull}24930[#24930] (issue: {issue}10708[#10708])

Internal::
* Add assertions enabled helper {pull}24834[#24834]

Java High Level REST Client::
* Add doc_count to ParsedMatrixStats {pull}24952[#24952] (issue: {issue}24776[#24776])
* Add fromXContent method to ClearScrollResponse {pull}24909[#24909]
* ClearScrollRequest to implement ToXContentObject {pull}24907[#24907]
* SearchScrollRequest to implement ToXContentObject {pull}24906[#24906] (issue: {issue}3889[#3889])
* Add aggs parsers for high level REST Client {pull}24824[#24824] (issues: {issue}23965[#23965], {issue}23973[#23973], {issue}23974[#23974], {issue}24085[#24085], {issue}24160[#24160], {issue}24162[#24162], {issue}24182[#24182], {issue}24183[#24183], {issue}24208[#24208], {issue}24213[#24213], {issue}24239[#24239], {issue}24284[#24284], {issue}24312[#24312], {issue}24330[#24330], {issue}24365[#24365], {issue}24371[#24371], {issue}24442[#24442], {issue}24521[#24521], {issue}24524[#24524], {issue}24564[#24564], {issue}24583[#24583], {issue}24589[#24589], {issue}24648[#24648], {issue}24667[#24667], {issue}24675[#24675], {issue}24682[#24682], {issue}24700[#24700], {issue}24706[#24706], {issue}24717[#24717], {issue}24720[#24720], {issue}24738[#24738], {issue}24746[#24746], {issue}24789[#24789], {issue}24791[#24791], {issue}24794[#24794], {issue}24796[#24796], {issue}24822[#24822])

Mapping::
* Identify documents by their `_id`. {pull}24460[#24460]

Packaging::
* Set number of processes in systemd unit file {pull}24970[#24970] (issue: {issue}20874[#20874])

Plugin Lang Painless::
* Make Painless Compiler Use an Instance Per Context {pull}24972[#24972]
* Make PainlessScript An Interface {pull}24966[#24966]

Recovery::
* Introduce primary context {pull}25031[#25031] (issue: {issue}10708[#10708])

Scripting::
* Add StatefulFactoryType as optional intermediate factory in script contexts {pull}24974[#24974] (issue: {issue}20426[#20426])
* Make contexts available to ScriptEngine construction {pull}24896[#24896]
* Make ScriptEngine.compile generic on the script context {pull}24873[#24873]
* Add instance and compiled classes to script contexts {pull}24868[#24868]

Search::
* Eliminate array access in tight loops when profiling is enabled. {pull}24959[#24959]
* Support Multiple Inner Hits on a Field Collapse Request {pull}24517[#24517]
* Expand cross cluster search indices for search requests to the concrete index or to it's aliases {pull}24502[#24502]

Search Templates::
* Add max concurrent searches to multi template search {pull}24255[#24255] (issues: {issue}20912[#20912], {issue}21907[#21907])

Sequence IDs::
* Fill gaps on primary promotion {pull}24945[#24945] (issue: {issue}10708[#10708])
* Introduce clean transition on primary promotion {pull}24925[#24925] (issue: {issue}10708[#10708])
* Guarantee that translog generations are seqNo conflict free {pull}24825[#24825] (issues: {issue}10708[#10708], {issue}24779[#24779])
* Inline global checkpoints {pull}24513[#24513] (issue: {issue}10708[#10708])

Snapshot/Restore::
* Enhances get snapshots API to allow retrieving repository index only {pull}24477[#24477] (issue: {issue}24288[#24288])



[[bug-6.0.0-alpha2]]
[float]
=== Bug fixes

Aggregations::
* Terms aggregation should remap global ordinal buckets when a sub-aggregator is used to sort the terms {pull}24941[#24941] (issue: {issue}24788[#24788])
* Correctly set doc_count when MovAvg "predicts" values on existing buckets {pull}24892[#24892] (issue: {issue}24327[#24327])
* DateHistogram: Fix `extended_bounds` with `offset` {pull}23789[#23789] (issue: {issue}23776[#23776])
* Fix ArrayIndexOutOfBoundsException when no ranges are specified in the query {pull}23241[#23241] (issue: {issue}22881[#22881])

Analysis::
* PatternAnalyzer should lowercase wildcard queries when `lowercase` is true. {pull}24967[#24967]

Cache::
* fix bug of weight computation {pull}24856[#24856]

Core::
* Fix cache expire after access {pull}24546[#24546]

Index APIs::
* Validates updated settings on closed indices {pull}24487[#24487] (issue: {issue}23787[#23787])

Ingest::
* Fix floating-point error when DateProcessor parses UNIX {pull}24947[#24947]
* add option for _ingest.timestamp to use new ZonedDateTime (5.x backport) {pull}24030[#24030] (issues: {issue}23168[#23168], {issue}23174[#23174])

Inner Hits::
* Fix Source filtering in new field collapsing feature {pull}24068[#24068] (issue: {issue}24063[#24063])

Internal::
* Ensure remote cluster is connected before fetching `_field_caps` {pull}24845[#24845] (issue: {issue}24763[#24763])

Network::
* Fix error message if an incompatible node connects {pull}24884[#24884]

Plugins::
* Fix plugin installation permissions {pull}24527[#24527] (issue: {issue}24480[#24480])

Scroll::
* Fix single shard scroll within a cluster with nodes in version `>= 5.3` and `<= 5.3` {pull}24512[#24512]

Search::
* Fix script field sort returning Double.MAX_VALUE for all documents {pull}24942[#24942] (issue: {issue}24940[#24940])
* Compute the took time of the query after the expand phase of field collapsing {pull}24902[#24902] (issue: {issue}24900[#24900])

Sequence IDs::
* Handle primary failure handling replica response {pull}24926[#24926] (issue: {issue}24935[#24935])

Snapshot/Restore::
* Fix inefficient (worst case exponential) loading of snapshot repository {pull}24510[#24510] (issue: {issue}24509[#24509])

Stats::
* Avoid double decrement on current query counter {pull}24922[#24922] (issues: {issue}22996[#22996], {issue}24872[#24872])
* Adjust available and free bytes to be non-negative on huge FSes {pull}24911[#24911] (issues: {issue}23093[#23093], {issue}24453[#24453])

Suggesters::
* Fix context suggester to read values from keyword type field {pull}24200[#24200] (issue: {issue}24129[#24129])


