DoubleValuesSource is the type-safe replacement for ValueSource in the lucene
core. Most of elasticsearch has moved to use these, but lang-expressions is still
using the old version. This commit migrates lang-expressions as well.
It's simple to deprecate a field used in an ObjectParser just by adding deprecation
markers to the relevant ParseField objects. The warnings themselves don't currently
have any context - they simply say that a deprecated field has been used, but not
where in the input xcontent it appears. This commit adds the parent object parser
name and XContentLocation to these deprecation messages.
Note that the context is automatically stripped from warning messages when they
are asserted on by integration tests and REST tests, because randomization of
xcontent type during these tests means that the XContentLocation is not constant
This commit, built on top of #51708, allows to modify shard search requests based on informations collected on other shards. It is intended to speed up sorted queries on time-based indices. For queries that are only interested in the top documents.
This change will rewrite the shard queries to match none if the bottom sort value computed in prior shards is better than all values in the shard.
For queries that mix top documents and aggregations this change will reset the size of the top documents to 0 instead of rewriting to match none.
This means that we don't need to keep a search context open for this shard since we know in advance that it doesn't contain any competitive hit.
The highlighting phase for percolator queries currently uses some custom query
traversal logic to find all instances of PercolatorQuery in the query tree for the
current search context. This commit converts things to instead use a QueryVisitor,
which future-proofs us against new wrapper queries or queries from custom
plugins that the percolator module doesn't know about.
Re-applies the change from #53523 along with test fixes.
closes#53626closes#53624closes#53622closes#53625
Co-authored-by: Nik Everett <nik9000@gmail.com>
Co-authored-by: Lee Hinman <dakrone@users.noreply.github.com>
Co-authored-by: Jake Landis <jake.landis@elastic.co>
This begins to clean up how `PipelineAggregator`s and executed.
Previously, we would create the `PipelineAggregator`s on the data nodes
and embed them in the aggregation tree. When it came time to execute the
pipeline aggregation we'd use the `PipelineAggregator`s that were on the
first shard's results. This is inefficient because:
1. The data node needs to make the `PipelineAggregator` only to
serialize it and then throw it away.
2. The coordinating node needs to deserialize all of the
`PipelineAggregator`s even though it only needs one of them.
3. You end up with many `PipelineAggregator` instances when you only
really *need* one per pipeline.
4. `PipelineAggregator` needs to implement serialization.
This begins to undo these by building the `PipelineAggregator`s directly
on the coordinating node and using those instead of the
`PipelineAggregator`s in the aggregtion tree. In a follow up change
we'll stop serializing the `PipelineAggregator`s to node versions that
support this behavior. And, one day, we'll be able to remove
`PipelineAggregator` from the aggregation result tree entirely.
Importantly, this doesn't change how pipeline aggregations are declared
or parsed or requested. They are still part of the `AggregationBuilder`
tree because *that* makes sense.
When 'rest_track_total_hits_as_int' is set to true, the total hits count in the response should be accurate. So we should set trackTotalHits to true if need when parsing the inline script of a search template request.
Closes#52801
This commit upgrades the jackson-databind depdendency to
2.8.11.6. Additionally, we revert a previous change that put
ingest-geoip on the version of jackson-databind from the version
properties file. This is because upgrading ingest-geoip to a later
version of jackson-databind also requires an upgrade to the geoip2
dependency which is currently blocked. Therefore, if we can get to a
point where we otherwise upgrade our Jackson dependencies, we do not
want ingest-geoip to automatically come along with it.
Lucene 8.5.0 release candidates are imminent. This commit upgrades master to use
the latest snapshot to check that there are no last-minute bugs or regressions.
This commit introduces a module for Kibana that exposes REST APIs that
will be used by Kibana for access to its system indices. These APIs are wrapped
versions of the existing REST endpoints. A new setting is also introduced since
the Kibana system indices' names are allowed to be changed by a user in case
multiple instances of Kibana use the same instance of Elasticsearch.
Additionally, the ThreadContext has been extended to indicate that the use of
system indices may be allowed in a request. This will be built upon in the future
for the protection of system indices.
Backport of #52385
ObjectParser allows you to declare a set of required fields, such that at least one
of the set must appear in an xcontent object for it to be valid. This commit adds
the similar concept of a set of exclusive fields, such that at most one of the set
must be present. It also enables required fields on ConstructingObjectParser, and
re-implements PercolateQueryBuilder.fromXContent() to use object parsing as
an example of how this works.
This change adds the recall@k metric and refactors precision@k to match
the new metric.
Recall@k is an important metric to use for learning to rank (LTR)
use-cases. Candidate generation or first ranking phase ranking functions
are often optimized for high recall, in order to generate as many
relevant candidates in the top-k as possible for a second phase of
ranking. Adding this metric allows tuning that base query for LTR.
See: https://github.com/elastic/elasticsearch/issues/51676
Backports: https://github.com/elastic/elasticsearch/pull/52577
Generalize how queries on `_index` are handled at rewrite time (#52486)
Since this change refactors rewrites, I also took it as an opportunity to adrress #49254: instead of returning the same queries you would get on a keyword field when a field is unmapped, queries get rewritten to a MatchNoDocsQueryBuilder.
This change exposed a couple bugs, like the fact that the percolator doesn't rewrite queries at query time, or that the significant_terms aggregation doesn't rewrite its inner filter, which I fixed.
Closes#49254
Commit #52748 fixed a bug where percolate queries wrapped in a constant score
could report incorrect matches. This commit adds a test to check that it also fixes
the case where a percolate query is sorted by something other than score.
Closes#52618
Lucene's RAMDirectory has been deprecated. This commit replaces all uses of
RAMDirectory in elasticsearch with the newer ByteBuffersDirectory. Most uses
are in tests, but the percolator and painless executor may get some small speedups.
The block setup by the test could be released by the nodes cluster info
thread before the disk threshold decider was disabled, now disable
decider first.
Currently, date ranges queries using NOW-based date math are rewritten to
MatchAllDocs queries when being preprocessed for the percolator. However,
since we added the verification step, this can result in incorrect matches when
percolator queries are run without scores. This commit changes things to instead
wrap date queries that use NOW with a new DateRangeIncludingNowQuery.
This is a simple wrapper query that returns its delegate at rewrite time, but it can
be detected by the percolator QueryAnalyzer and be dealt with accordingly.
This also allows us to remove a method on QueryRewriteContext, and push all
logic relating to NOW-based ranges into the DateFieldMapper.
Fixes#52617
Before boost in script_score query was wrongly applied only to the subquery.
This commit makes sure that the boost is applied to the whole score
that comes out of script.
Closes#48465
We consider index level read_only_allow_delete blocks temporary since
the DiskThresholdMonitor can automatically release those when an index
is no longer allocated on nodes above high threshold.
The rest status has therefore been changed to 429 when encountering this
index block to signal retryability to clients.
Related to #49393
This commit modifies the codebase so that our production code uses a
single instance of the IndexNameExpressionResolver class. This change
is being made in preparation for allowing name expression resolution
to be augmented by a plugin.
In order to remove some instances of IndexNameExpressionResolver, the
single instance is added as a parameter of Plugin#createComponents and
PersistentTaskPlugin#getPersistentTasksExecutor.
Backport of #52596
Backport of #52542.
This commit is part of issue #40366 to remove disabled Xlint warnings
from gradle files. In particular, it removes the Xlint exclusions from
the following files:
- benchmarks/build.gradle
- client/client-benchmark-noop-api-plugin/build.gradle
- x-pack/qa/rolling-upgrade/build.gradle
- x-pack/qa/third-party/active-directory/build.gradle
- modules/transport-netty4/build.gradle
For the first three files no code adjustments were needed. For
x-pack/qa/third-party/active-directory move the suppression at the code
level. For transport-netty4 replace the variable arguments with
ArrayLists and remove any redundant casts.
The `top_metrics` agg is kind of like `top_hits` but it only works on
doc values so it *should* be faster.
At this point it is fairly limited in that it only supports a single,
numeric sort and a single, numeric metric. And it only fetches the "very
topest" document worth of metric. We plan to support returning a
configurable number of top metrics, requesting more than one metric and
more than one sort. And, eventually, non-numeric sorts and metrics. The
trick is doing those things fairly efficiently.
Co-Authored by: Zachary Tong <zach@elastic.co>
Add a new cluster setting `search.allow_expensive_queries` which by
default is `true`. If set to `false`, certain queries that have
usually slow performance cannot be executed and an error message
is returned.
- Queries that need to do linear scans to identify matches:
- Script queries
- Queries that have a high up-front cost:
- Fuzzy queries
- Regexp queries
- Prefix queries (without index_prefixes enabled
- Wildcard queries
- Range queries on text and keyword fields
- Joining queries
- HasParent queries
- HasChild queries
- ParentId queries
- Nested queries
- Queries on deprecated 6.x geo shapes (using PrefixTree implementation)
- Queries that may have a high per-document cost:
- Script score queries
- Percolate queries
Closes: #29050
(cherry picked from commit a8b39ed842c7770bd9275958c9f747502fd9a3ea)
This commit changes how RestHandlers are registered with the
RestController so that a RestHandler no longer needs to register itself
with the RestController. Instead the RestHandler interface has new
methods which when called provide information about the routes
(method and path combinations) that are handled by the handler
including any deprecated and/or replaced combinations.
This change also makes the publication of RestHandlers safe since they
no longer publish a reference to themselves within their constructors.
Closes#51622
Co-authored-by: Jason Tedor <jason@tedor.me>
Backport of #51950
Now that the FIPS 140 security provider is simply a test dependency
we don't need the thirdPartyAudit exceptions, but plugin-cli and
transport-netty4 do need jarHell disabled as they use the non fips
BouncyCastle security provider as a test dependency too.
* Improve Painless compilation performance for nested conditionals (#52056)
This PR changes how conditional expression is handled in `PainlessParser`
in a way that avoids the need for backtracking, which led to exponential
compilation times in case of nested conditionals.
The test was added ensures that we can compile deeply nested conditionals.
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
* Fix Map.of in Java8
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
This change fixes flakiness in `CsvProcessorTests` where source field
can be the same as one of the headers used by tests which messes up
asserts when we check that field is not present after processor run.
Closes#50209
* Add empty_value parameter to CSV processor
This change adds `empty_value` parameter to the CSV processor.
This value is used to fill empty fields. Fields will be skipped
if this parameter is ommited. This behavior is the same for both
quoted and unquoted fields.
* docs updated
* Fix compilation problem
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
when a timezone is not provided Ingest logic should consider a time to be in a timezone provided as a parameter.
When a timezone is provided Ingest should recalculate a time to the timezone provided as a parameter
closes#51108
backport(#51215)
While we use `== false` as a more visible form of boolean negation
(instead of `!`), the true case is implied and the true value does not
need to explicitly checked. This commit converts cases that have slipped
into the code checking for `== true`.
rest-api-spec/test/10_basic.yml would check that transport_types is
`netty4` but we run FIPS 140 tests with default distribution and
transport_types is `security4`
This commit deprecates the creation of dot-prefixed index names (e.g.
.watches) unless they are either 1) a hidden index, or 2) registered by
a plugin that extends SystemIndexPlugin. This is the first step
towards more thorough protections for system indices.
This commit also modifies several plugins which use dot-prefixed indices
to register indices they own as system indices, and adds a plugin to
register .tasks as a system index.
We still test remote reindex against version 0.90. This failed on mac a
few times and rather than spend time investigating this, we no longer
test remote reindex against 0.90 on mac.
Closes#51202
This change changes the way to run our test suites in
JVMs configured in FIPS 140 approved mode. It does so by:
- Configuring any given runtime Java in FIPS mode with the bundled
policy and security properties files, setting the system
properties java.security.properties and java.security.policy
with the == operator that overrides the default JVM properties
and policy.
- When runtime java is 11 and higher, using BouncyCastle FIPS
Cryptographic provider and BCJSSE in FIPS mode. These are
used as testRuntime dependencies for unit
tests and internal clusters, and copied (relevant jars)
explicitly to the lib directory for testclusters used in REST tests
- When runtime java is 8, using BouncyCastle FIPS
Cryptographic provider and SunJSSE in FIPS mode.
Running the tests in FIPS 140 approved mode doesn't require an
additional configuration either in CI workers or locally and is
controlled by specifying -Dtests.fips.enabled=true
* Refactor ForEachProcessor to use iteration instead of recursion (#51104)
* Refactor ForEachProcessor to use iteration instead of recursion
This change makes ForEachProcessor iterative and still non-blocking.
In case of non-async processors we use single for loop and no recursion at all.
In case of async processors we continue work on either current thread or thread
started by downstream processor, whichever is slower (usually processor thread).
Everything is synchronised by single atomic variable.
Relates #50514
* Update IngestCommonPlugin.java
Add the character position of a scripting error to error responses.
The contents of the `position` field are experimental and subject to
change. Currently, `offset` refers to the character location where the
error was encountered, `start` and `end` define a range of characters
that contain the error.
eg.
```
{
"error": {
"root_cause": [
{
"type": "script_exception",
"reason": "runtime error",
"script_stack": [
"y = x;",
" ^---- HERE"
],
"script": "def x = new ArrayList(); Map y = x;",
"lang": "painless",
"position": {
"offset": 33,
"start": 29,
"end": 35
}
}
```
Refs: #50993
This replaces the message we return for unknown queries with the standard
one that we use for unknown fields from `ObjectParser`. This is nice
because it includes "did you mean". One day we might convert parsing
queries to using object parser, but that looks complex. This change is
much smaller and seems useful.
The PreConfiguredTokenFilter#singletonWithVersion uses the version
internally for the token filter factories but it registers only one
instance in the cache and not one instance per version. This can lead
to exceptions like the one described in #50734 since the singleton is
created and cached using the version created of the first index
that is processed.
Remove the singletonWithVersion() methods and use the
elasticsearchVersion() methods instead.
Fixes: #50734
(cherry picked from commit 24e1858)
Backport: #50467
This commit adds the name of the current pipeline to ingest metadata.
This pipeline name is accessible under the following key: '_ingest.pipeline'.
Example usage in pipeline:
PUT /_ingest/pipeline/2
{
"processors": [
{
"set": {
"field": "pipeline_name",
"value": "{{_ingest.pipeline}}"
}
}
]
}
Closes#42106
Check it out:
```
$ curl -u elastic:password -HContent-Type:application/json -XPOST localhost:9200/test/_update/foo?pretty -d'{
"dac": {}
}'
{
"error" : {
"root_cause" : [
{
"type" : "x_content_parse_exception",
"reason" : "[2:3] [UpdateRequest] unknown field [dac] did you mean [doc]?"
}
],
"type" : "x_content_parse_exception",
"reason" : "[2:3] [UpdateRequest] unknown field [dac] did you mean [doc]?"
},
"status" : 400
}
```
The tricky thing about implementing this is that x-content doesn't
depend on Lucene. So this works by creating an extension point for the
error message using SPI. Elasticsearch's server module provides the
"spell checking" implementation.
s
We deprecated and removed the camel-case versions of the nGram and edgeNGram
filters a while ago and we should do the same with the nGram and edgeNGram tokenizers.
This PR deprecates the use of these names in favour of ngram and edge_ngram in
7. Usage will be disallowed on new indices starting with 8 then.
Generally speaking, deprecated analysis components in elasticsearch will issue deprecation
warnings when they are first used. However, this means that no warnings are emitted when
indexes are created with deprecated components, and users have to actually index a document
to see warnings. This makes it much harder to see these warnings and act on them at
appropriate times.
This is worse in the case where components throw exceptions on upgrade. In this case, users
will not be aware of a problem until a document is indexed, instead of at index creation time.
This commit adds a new check that pushes an empty string through all user-defined analyzers
and normalizers when an IndexAnalyzers object is built for each index; deprecation warnings
and exceptions are now emitted when indexes are created or opened.
Fixes#42349
A very large number of recursive calls can cause a stack overflow
exception. This commit forks the recursive calls for non-async
processors. Once forked, each thread will handle at most 10
recursive calls to help keep the stack size and thread count
down to a reasonable size.
Currently, if an updateable synonym filter is included in a multiplexer filter,
it is not reloaded via the _reload_search_analyzers because the multiplexer
itself doesn't pass on the analysis mode of the filters it contains, so its not
recognized as "updateable" in itself. Instead we can check and merge the
AnalysisMode settings of all filters in the multiplexer and use the resulting
mode (e.g. search-time only) for the multiplexer itself, thus making any synonym
filters contained in it reloadable. This, of course, will also make the
analyzers using the multiplexer be usable at search-time only.
Closes#50554
ElasticsearchException.guessRootCauses would return wrapper exception if
inner exception was not an ElasticsearchException. Fixed to never return
wrapper exceptions.
At least following APIs change root_cause.0.type as a result:
_update with bad script
_index with bad pipeline
Relates #50417
This PR adds per-field metadata that can be set in the mappings and is later
returned by the field capabilities API. This metadata is completely opaque to
Elasticsearch but may be used by tools that index data in Elasticsearch to
communicate metadata about fields with tools that then search this data. A
typical example that has been requested in the past is the ability to attach
a unit to a numeric field.
In order to not bloat the cluster state, Elasticsearch requires that this
metadata be small:
- keys can't be longer than 20 chars,
- values can only be numbers or strings of no more than 50 chars - no inner
arrays or objects,
- the metadata can't have more than 5 keys in total.
Given that metadata is opaque to Elasticsearch, field capabilities don't try to
do anything smart when merging metadata about multiple indices, the union of
all field metadatas is returned.
Here is how the meta might look like in mappings:
```json
{
"properties": {
"latency": {
"type": "long",
"meta": {
"unit": "ms"
}
}
}
}
```
And then in the field capabilities response:
```json
{
"latency": {
"long": {
"searchable": true,
"aggreggatable": true,
"meta": {
"unit": [ "ms" ]
}
}
}
}
```
When there are no conflicts, values are arrays of size 1, but when there are
conflicts, Elasticsearch includes all unique values in this array, without
giving ways to know which index has which metadata value:
```json
{
"latency": {
"long": {
"searchable": true,
"aggreggatable": true,
"meta": {
"unit": [ "ms", "ns" ]
}
}
}
}
```
Closes#33267
In order to ensure that logstash and Elasticsearch are able to understand
the same patterns, this commit adapts to changes in logstash, adds a few
patterns and changes a few.
When there several subqueries on different relations of the join field,
and only one of subqueries is using inner_hits, NPE occurs.
This PR prevents NPE error.
Closes#50539
With the rewrite of the percolator's QueryAnalyzer to use lucene's QueryVisitor API,
term queries that are direct children of a boolean query are handled separately from
other children. This works fine for conjunctions, but for disjunctions we need to
treat the extracted terms from these direct descendents along with extractions from
more deeply nested children to ensure that minimum-should-match requirements
are met correctly.
This commit changes the logic in QueryAnalyzer#getResult() to bundle child term
results with all other results before handling them.
Fixes#50305
*Most* of our parsing can be done without passing any extra context into
the parser that isn't already part of the xcontent stream. While I was
looking around at the places that *do* need a context I found a few
places that were declared to need a context but don't actually need it.
We have about 800 `ObjectParsers` in Elasticsearch, about 700 of which
are final. This is *probably* the right way to declare them because in
practice we never mutate them after they are built. And we certainly
don't change the static reference. Anyway, this adds `final` to these
parsers.
I found the non-final parsers with this:
```
diff \
<(find . -type f -name '*.java' -exec grep -iHe 'static.*PARSER\s*=' {} \+ | sort) \
<(find . -type f -name '*.java' -exec grep -iHe 'static.*final.*PARSER\s*=' {} \+ | sort) \
2>&1 | grep '^<'
```
We have about 800 `ObjectParsers` in Elasticsearch, about 700 of which
are final. This is *probably* the right way to declare them because in
practice we never mutate them after they are built. And we certainly
don't change the static reference. Anyway, this adds `final` to a bunch
of these parsers, mostly the ones in xpack and their "paired" parsers in
the high level rest client. I picked these just to have somewhere to
break the up the change so it wouldn't be huge.
I found the non-final parsers with this:
```
diff \
<(find . -type f -name '*.java' -exec grep -iHe 'static.*PARSER\s*=' {} \+ | sort) \
<(find . -type f -name '*.java' -exec grep -iHe 'static.*final.*PARSER\s*=' {} \+ | sort) \
2>&1 | grep '^<'
```
The camel-case `nGram` and `edgeNGram` filter names were deprecated in 6. We
currently throw errors on new indices when they are used. However these errors
are currently only thrown for pre-configured filters, adding them as custom
filters doesn't trigger the warning and error. This change adds the appropriate
deprecation warnings for `nGram` and `edgeNGram` respectively on version 7
indices.
Relates #50360
Avoid backwards incompatible changes for 8.x and 7.6 by removing type
restriction on compile and Factory. Factories may optionally implement
ScriptFactory. If so, then they can indicate determinism and thus
cacheability.
**Backport**
Relates: #49466
Cache results from queries that use scripts if they use only
deterministic API calls. Nondeterministic API calls are marked in the
whitelist with the `@nondeterministic` annotation. Examples are
`Math.random()` and `new Date()`.
Refs: #49466
There's flakiness in CsvProcesorTests, where tests fail if random document generator add field that should not be present. This change cleans generated document from these problematic fields.
Closes#50209
* Remove Unused Single Delete in BlobStoreRepository
There are no more production uses of the non-bulk delete or the delete that throws
on missing so this commit removes both these methods.
Only the bulk delete logic remains. Where the bulk delete was derived from single deletes,
the single delete code was inlined into the bulk delete method.
Where single delete was used in tests it was replaced by bulk deleting.
* CSV ingest processor (#49509)
This change adds new ingest processor that breaks line from CSV file into separate fields.
By default it conforms to RFC 4180 but can be tweaked.
Closes#49113
This makes two changes to the catch node:
1. Use SDeclaration to replace independent variable usage.
2. Use a DType to set a "minimum" exception type - this allows us to require
users to continue using Exception as "minimum" type for catch blocks, but
for us to internally catch Error/Throwable. This is a required step to
removing custom try/catch blocks from SClass.
When the query analyzer examines a conjunction containing both terms and ranges,
it should only include ranges in the minimum_should_match calculation if there are no
other range queries on that same field within the conjunction. This is because we cannot
build a selection query over disjoint ranges on the same field, and it is not easy to check
if two range queries have an overlap.
The current logic to calculate this just sets minimum_should_match to 1 or 0, dependent
on whether or not the current range is over a field that has already been seen. However, this
can be incorrect in the case that there are terms in the same match group which adjust the
minimum_should_match downwards. Instead, the logic should be changed to match the
terms extraction, whereby we adjust minimum_should_match downwards if we have already
seen a range field.
Fixes#49684
* Allow list of IPs in geoip ingest processor
This change lets you use array of IPs in addition to string in geoip processor source field.
It will set array containing geoip data for each element in source, unless first_only parameter
option is enabled, then only first found will be returned.
Closes#46193
In order to cache script results in the query shard cache, we need to
check if scripts are deterministic. This change adds a default method
to the script factories, `isResultDeterministic() -> false` which is
used by the `QueryShardContext`.
Script results were never cached and that does not change here. Future
changes will implement this method based on whether the results of the
scripts are deterministic or not and therefore cacheable.
Refs: #49466
**Backport**
Moved the deprecation warning to ReindexValidator to ensure it runs
early and works with resilient reindex. Also check that the warning
is reported back for wait_for_completion=false.
Follow-up to #49458
This PR adds 3 nodes to handle types defined by a front-end creating a
Painless AST. These types are decided with data immutability in mind -
hence the reason for more than a single node.
Historically only two things happened in the final reduction:
empty buckets were filled, and pipeline aggs were reduced (since it
was the final reduction, this was safe). Usage of the final reduction
is growing however. Auto-date-histo might need to perform
many reductions on final-reduce to merge down buckets, CCS
may need to side-step the final reduction if sending to a
different cluster, etc
Having pipelines generate their output in the final reduce was
convenient, but is becoming increasingly difficult to manage
as the rest of the agg framework advances.
This commit decouples pipeline aggs from the final reduction by
introducing a new "top level" reduce, which should be called
at the beginning of the reduce cycle (e.g. from the SearchPhaseController).
This will only reduce pipeline aggs on the final reduce after
the non-pipeline agg tree has been fully reduced.
By separating pipeline reduction into their own set of methods,
aggregations are free to use the final reduction for whatever
purpose without worrying about generating pipeline results
which are non-reducible
This cleans up two minor things.
- Cleans up style of == false
- Pulls maxLoopCounter into a member variable instead of accessing
CompilerSettings multiple times in the SFunction node
Adds `GET /_script_language` to support Kibana dynamic scripting
language selection.
Response contains whether `inline` and/or `stored` scripts are
enabled as determined by the `script.allowed_types` settings.
For each scripting language registered, such as `painless`,
`expression`, `mustache` or custom, available contexts for the language
are included as determined by the `script.allowed_contexts` setting.
Response format:
```
{
"types_allowed": [
"inline",
"stored"
],
"language_contexts": [
{
"language": "expression",
"contexts": [
"aggregation_selector",
"aggs"
...
]
},
{
"language": "painless",
"contexts": [
"aggregation_selector",
"aggs",
"aggs_combine",
...
]
}
...
]
}
```
Fixes: #49463
**Backport**