Now that we have incremental reduce functions for topN and aggregations
we can set the default for `action.search.shard_count.limit` to unlimited.
This still allows users to restrict these settings while by default we executed
across all shards matching the search requests index pattern.
_field_stats has evolved quite a lot to become a multi purpose API capable of retrieving the field capabilities and the min/max value for a field.
In the mean time a more focused API called `_field_caps` has been added, this enpoint is a good replacement for _field_stats since he can
retrieve the field capabilities by just looking at the field mapping (no lookup in the index structures).
Also the recent improvement made to range queries makes the _field_stats API obsolete since this queries are now rewritten per shard based on the min/max found for the field.
This means that a range query that does not match any document in a shard can return quickly and can be cached efficiently.
For these reasons this change deprecates _field_stats. The deprecation should happen in 5.4 but we won't remove this API in 6.x yet which is why
this PR is made directly to 6.0.
The rest tests have also been adapted to not throw an error while this change is backported to 5.4.
This commit removes some leniency from the plugin service which skips
hidden files in the plugins directory. We really want to ensure the
integrity of the plugin folder, so hasta la vista leniency.
Relates #23982
They needed to be updated now that Painless is the default and
the non-sandboxed scripting languages are going away or gone.
I dropped the entire section about customizing the classloader
whitelists. In master this barely does anything (exposes more
things to expressions).
Before now ranges where forbidden, because the percolator query itself could get cached and then the percolator queries with now ranges that should no longer match, incorrectly will continue to match.
By disabling caching when the `percolator` is being used, the percolator can now correctly support range queries with now based ranges.
I think this is the right tradeoff. The percolator query is likely to not be the same between search requests and disabling range queries with now ranges really disabled people using the percolator for their use cases.
Also fixed an issue that existed in the percolator fieldmapper, it was unable to find forbidden queries inside `dismax` queries.
Closes#23859
While there are use-cases where a single-node is in production, there
are also use-cases for starting a single-node that binds transport to an
external interface where the node is not in production (for example, for
testing the transport client against a node started in a Docker
container). It's tricky to balance the desire to always enforce the
bootstrap checks when a node might be in production with the need for
the community to perform testing in situations that would trip the
bootstrap checks. This commit enables some flexibility for these
users. By setting the discovery type to "single-node", we disable the
bootstrap checks independently of how transport is bound. While this
sounds like a hole in the bootstrap checks, the bootstrap checks can
already be avoided in the single-node use-case by binding only HTTP but
not transport. For users that are genuinely in production on a
single-node use-case with transport bound to an external use-case, they
can set the system property "es.enable.bootstrap.checks" to force
running the bootstrap checks. It would be a mistake for them not to do
this.
Relates #23598
Fielddata can no longer be configured to be loaded eagerly (it only accepts
`true` and `false`), so this line is a little misleading because it talks about
a procedure we can no longer do.
Converts the analysis docs to that were marked as json into `CONSOLE`
format. A few of them were in yaml but marked as json for historical
reasons. I added more complete examples for a few of the less obvious
sounding ones.
Relates to #18160
The pattern-analyzer docs contained a snippet that was an expanded
regex that was marked as `[source,js]`. This changes it to
`[source,regex]`.
The htmlstrip-charfilter and pattern-replace-charfilter docs had
examples that were actually a list of tokens but marked `[source,js]`.
This marks them as `[source,text]` so they don't count as unconverted
CONSOLE snippets.
The pattern-replace-charfilter also had a doc who's test was
skipped because of funny interaction with the test framework. This
fixes the test.
Three more down, eighty-two to go.
Relates to #18160
CONSOLEifies the lang-analyzer docs and replaces the (invalid)
empty `keyword_marker` setups that were on the page with one
that contains the word "example" translated into the appropriate
language.
Relates to #18160
This change introduces a new API called `_field_caps` that allows to retrieve the capabilities of specific fields.
Example:
````
GET t,s,v,w/_field_caps?fields=field1,field2
````
... returns:
````
{
"fields": {
"field1": {
"string": {
"searchable": true,
"aggregatable": true
}
},
"field2": {
"keyword": {
"searchable": false,
"aggregatable": true,
"non_searchable_indices": ["t"]
"indices": ["t", "s"]
},
"long": {
"searchable": true,
"aggregatable": false,
"non_aggregatable_indices": ["v"]
"indices": ["v", "w"]
}
}
}
}
````
In this example `field1` have the same type `text` across the requested indices `t`, `s`, `v`, `w`.
Conversely `field2` is defined with two conflicting types `keyword` and `long`.
Note that `_field_caps` does not treat this case as an error but rather return the list of unique types seen for this field.
I managed to push the last one without testing it because I'd changed
the way I run tests locally and hadn't picked it up. Ooops. This one
works better.
All the docs for the `exists` query that aren't marked as `CONSOLE`
aren't actually `CONSOLE`-worthy so this marks them as `NOTCONSOLE`.
It also rewrites the text around `missing` query. Since it was
removed in 5.0 we don't need to talk about it in the 6.0 docs.
Relates to #18160
Turns the top example in each of the geo aggregation docs into a working
example that can be opened in CONSOLE. Subsequent examples can all also
be opened in console and will work after you've run the first example.
All examples are tested as part of the build.
This commit clarifies the preference docs regarding the explanation of
how operations are routed by default. In particular, the previous use of
"shard replicas" was confusing as it could imply an operation would only
be routed to replicas by default.
Relates #23794
This commit adds support for the pattern keyword marker filter in
Lucene. Previously, the keyword marker filter in Elasticsearch
supported specifying a keywords set or a path to a set of keywords.
This commit exposes the regular expression pattern based keyword marker
filter also available in Lucene, so that any token matching the pattern
specified by the `keywords_pattern` setting is excluded from being
stemmed by any stemming filters.
Closes#4877
As the query of a search request defaults to match_all,
calling _delete_by_query without an explicit query may
result in deleting all data.
In order to protect users against falling into that
pitfall, this commit adds a check to require the explicit
setting of a query.
Closes#23629
This commit adds the boolean similarity scoring from Lucene to
Elasticsearch. The boolean similarity provides a means to specify that
a field should not be scored with typical full-text ranking algorithms,
but rather just whether the query terms match the document or not.
Boolean similarity scores a query term equal to its query boost only.
Boolean similarity is available as a default similarity option and thus
a field can be specified to have boolean similarity by declaring in its
mapping:
"similarity": "boolean"
Closes#6731
The OpenJDK project provides early-access builds of upcoming
releases. These early-access builds are not suitable for
production. These builds sometimes end up on systems due to aggressive
packaging (e.g., Ubuntu). This commit adds a bootstrap check to ensure
these early-access builds are not being used in production.
Relates #23743
This is especially useful when we rewrite the query because the result of the rewrite can be very different on different shards. See #18254 for example.
* Add support for fragment_length in the unified highlighter
This commit introduce a new break iterator (a BoundedBreakIterator) designed for the unified highlighter
that is able to limit the size of fragments produced by generic break iterator like `sentence`.
The `unified` highlighter now supports `boundary_scanner` which can `words` or `sentence`.
The `sentence` mode will use the bounded break iterator in order to limit the size of the sentence to `fragment_length`.
When sentences bigger than `fragment_length` are produced, this mode will break the sentence at the next word boundary **after**
`fragment_length` is reached.
The reindex API is mature now, and we will work to maintain backwards
compatibility in accordance with our backwards compatibility
policy. This commit unmarks the reindex API as experimental.
Relates #23621
In SI units, "kilobyte" or "kB" would mean 1000 bytes, whereas "KiB" is
used for 1024. Add a note in `api-conventions.asciidoc` to clarify the
meaning in Elasticsearch.
This commit adds a system property that enables end-users to explicitly
enforce the bootstrap checks, independently of the binding of the
transport protocol. This can be useful for single-node production
systems that do not bind the transport protocol (and thus the bootstrap
checks would not be enforced).
Relates #23585
This commit adds the size of the cluster state to the response for the
get cluster state API call (GET /_cluster/state). The size that is
returned is the size of the full cluster state in bytes when compressed.
This is the same size of the full cluster state when serialized to
transmit over the network. Specifying the ?human flag displays the
compressed size in a more human friendly manner. Note that even if the
cluster state request filters items from the cluster state (so a subset
of the cluster state is returned), the size that is returned is the
compressed size of the entire cluster state.
Closes#3415
This change exposes the new Lucene graph based word delimiter token filter in the analysis filters.
Unlike the `word_delimiter` this token filter named `word_delimiter_graph` correctly handles multi terms expansion at query time.
Closes#23104
This commit adds a boundary_scanner property to the search highlight
request so the user can specify different boundary scanners:
* `chars` (default, current behavior)
* `word` Use a WordBreakIterator
* `sentence` Use a SentenceBreakIterator
This commit also adds "boundary_scanner_locale" to define which locale
should be used when scanning the text.
Today we have multiple ways to define settings when a user needs to create a repository:
* in `elasticsearch.yml` file using `repositories.azure` prefix
* when creating the repository itself with `PUT _snaphot/repo`
The plan is to:
* Deprecate `repositories.azure` settings in 5.x (done with #22856)
* Remove in 6.x (this PR)
Related to #22800
This commit enforces the requirement of Content-Type for the REST layer and removes the deprecated methods in transport
requests and their usages.
While doing this, it turns out that there are many places where *Entity classes are used from the apache http client
libraries and many of these usages did not specify the content type. The methods that do not specify a content type
explicitly have been added to forbidden apis to prevent more of these from entering our code base.
Relates #19388
* Console-ify curl statements for allocation explain API docs
Relates to #23001
* Fix tests
* Remove exclusion from build.gradle
* Call out index creation in prose
* Add console back and skip test
This commit brings the snapshot documentation in conformity
with the CONSOLE format, and fixes the docs so that the documentation
tests can be run against them.
When nested objects are present in the mappings, many queries get deoptimized
due to the need to exclude documents that are not in the right space. For
instance, a filter is applied to all queries that prevents them from matching
non-root documents (`+*:* -_type:__*`). Moreover, a filter is applied to all
child queries of `nested` queries in order to make sure that the child query
only matches child documents (`_type:__nested_path`), which is required by
`ToParentBlockJoinQuery` (the Lucene query behing Elasticsearch's `nested`
queries).
These additional filters slow down `nested` queries. In 1.7-, the cost was
somehow amortized by the fact that we cached filters very aggressively. However,
this has proven to be a significant source of slow downs since 2.0 for users
of `nested` mappings and queries, see #20797.
This change makes the filtering a bit smarter. For instance if the query is a
`match_all` query, then we need to exclude nested docs. However, if the query
is `foo: bar` then it may only match root documents since `foo` is a top-level
field, so no additional filtering is required.
Another improvement is to use a `FILTER` clause on all types rather than a
`MUST_NOT` clause on all nested paths when possible since `FILTER` clauses
are more efficient.
Here are some examples of queries and how they get rewritten:
```
"match_all": {}
```
This query gets rewritten to `ConstantScore(+*:* -_type:__*)` on master and
`ConstantScore(_type:AutomatonQuery {\norg.apache.lucene.util.automaton.Automaton@4371da44})`
with this change. The automaton is the complement of `_type:__*` so it matches
the same documents, but is faster since it is now a positive clause. Simplistic
performance testing on a 10M index where each root document has 5 nested
documents on average gave a latency of 420ms on master and 90ms with this change
applied.
```
"term": {
"foo": {
"value": "0"
}
}
```
This query is rewritten to `+foo:0 #(ConstantScore(+*:* -_type:__*))^0.0` on
master and `foo:0` with this change: we do not need to filter nested docs out
since the query cannot match nested docs. While doing performance testing in
the same conditions as above, response times went from 250ms to 50ms.
```
"nested": {
"path": "nested",
"query": {
"term": {
"nested.foo": {
"value": "0"
}
}
}
}
```
This query is rewritten to
`+ToParentBlockJoinQuery (+nested.foo:0 #_type:__nested) #(ConstantScore(+*:* -_type:__*))^0.0`
on master and `ToParentBlockJoinQuery (nested.foo:0)` with this change. The
top-level filter (`-_type:__*`) could be removed since `nested` queries only
match documents of the parent space, as well as the child filter
(`#_type:__nested`) since the child query may only match nested docs since the
`nested` object has both `include_in_parent` and `include_in_root` set to
`false`. While doing performance testing in the same conditions as above,
response times went from 850ms to 270ms.
This pull request reuses the typed_keys parameter added in #22965, but this time it applies it to suggesters. When set to true, the suggester names in the search response will be prefixed with a prefix that reflects their type.
This changes removes the SearchResponseListener that was used by the ExpandCollapseSearchResponseListener to expand collapsed hits.
The removal of SearchResponseListener is not a breaking change because it was never released.
This change also replace the blocking call in ExpandCollapseSearchResponseListener by a single asynchronous multi search request. The parallelism of the expand request can be set via CollapseBuilder#max_concurrent_group_searches
Closes#23048
This pull request adds a new parameter to the REST Search API named `typed_keys`. When set to true, the aggregation names in the search response will be prefixed with a prefix that reflects the internal type of the aggregation.
Here is a simple example:
```
GET /_search?typed_keys
{
"aggs": {
"tweets_per_user": {
"terms": {
"field": "user"
}
}
},
"size": 0
}
```
And the response:
```
{
"aggs": {
"sterms:tweets_per_user": {
...
}
}
}
```
This parameter is intended to make life easier for REST clients that could parse back the prefix and could detect the type of the aggregation to parse. It could also be implemented for suggesters.
This commit removes support for the `application/x-ldjson` Content-Type header as this was only used in the first draft
of the spec and had very little uptake. Additionally, the docs for bulk and msearch have been updated to specifically
call out ndjson and mention that the newline character may be preceded by a carriage return.
Finally, the bulk request handling of the carriage return has been improved to remove this character from the source.
Closes#23025
Elasticsearch v5.0.0 uses allocation IDs to safely allocate primary shards whereas prior versions of ES used a version-based mode instead. Elasticsearch v5 still has support for version-based primary shard allocation as it needs to be able to load 2.x shards. ES v6 can drop the legacy support.
Since `_all` is now deprecated and cannot be set for new indices, we should also
disallow any field that has the `include_in_all` parameter set.
Resolves#22923
These need to be CONSOLEified *now* because we're starting to
require Content-Type headers and they didn't have any.
* cluster/reroute: Marked as CONSOLE but skipped because the docs
build runs with a single node.
* docs/bulk: Marked as NOTCONSOLE because the snippets describe
either examples or `curl` commands. Fixed the `curl` command to
include the `Content-Type` header.
* query-dsl/terms-query: Marked as CONSOLE.
* search/request/rescore: Marked as CONSOLE. Fixed deprecated
syntax.
Relates #23001
Relates #18160
This adds the `COPY AS CURL` and `VIEW IN CONSOLE` links to the docs
and causes the snippets to be tested during Elasticsearch's build.
Relates to #18160
This adds the `COPY AS CURL` and `VIEW IN CONSOLE` buttons to the
docs and makes the build execute the snippets as part of `docs:check`.
Relates to #18160
Painless uses Ruby-like method dispatch (reciever type, method name,
and arity) rather than Java-like (reciever type, method name, and
argument compile time types) or Groovy-like method dispatch (receiver
type, method name, and argument run time types). We do this for
mostly good reasons but we never documented it.
Relates to #22720
Today either all nodes in the cluster connect to remote clusters of only nodes
that have remote clusters configured in their node config. To allow global remote
cluster configuration but restrict connections to a set of nodes in the cluster
this change adds a new setting `search.remote.connect` (defaults to `true`) to allow
to disable remote cluster connections on a per node basis.
This changes the way that replica failures are handled such that not all
failures will cause the replica shard to be failed or marked as stale.
In some cases such as refresh operations, or global checkpoint syncs, it is
"okay" for the operation to fail without the shard being failed (because no data
is out of sync). In these cases, instead of failing the shard we should simply
fail the operation, and, in the event it is a user-facing operation, return a
5xx response code including the shard-specific failures.
This was accomplished by having two forms of the `Replicas` proxy, one that is
for non-write operations that does not fail the shard, and one that is for write
operations that will fail the shard when an operation fails.
Relates to #10708
It was accidentally renamed `enabled_position_increment` in the cleanups
for 5.0. This adds `enable_position_increment` as a deprecated alias
so it will continue to work.
This commit removes the following queries and parameters (which were deprecated in 5.0):
* GeoPointDistanceRangeQuery
* coerce, and ignore_malformed for GeoBoundingBoxQuery, GeoDistanceQuery, GeoPolygonQuery, and GeoDistanceSort
This change also removes the reference to the difference bewteen full name and index name.
They are always the same since 2.x and `name` does not refer anymore to `author.name` automatically.
A simple pattern must be used instead.
Remove redundant code that checks the field name twice.
This change adds a strict mode for xcontent parsing on the rest layer. The strict mode will be off by default for 5.x and in a separate commit will be enabled by default for 6.0. The strict mode, which can be enabled by setting `http.content_type.required: true` in 5.x, will require that all incoming rest requests have a valid and supported content type header before the request is dispatched. In the non-strict mode, the Content-Type header will be inspected and if it is not present or not valid, we will continue with auto detection of content like we have done previously.
The content type header is parsed to the matching XContentType value with the only exception being for plain text requests. This value is then passed on with the content bytes so that we can reduce the number of places where we need to auto-detect the content type.
As part of this, many transport requests and builders were updated to provide methods that
accepted the XContentType along with the bytes and the methods that would rely on auto-detection have been deprecated.
In the non-strict mode, deprecation warnings are issued whenever a request with body doesn't provide the Content-Type header.
See #19388
GeoDistance query, sort, and scripts make use of a crazy GeoDistance enum for handling 4 different ways of computing geo distance: SLOPPY_ARC, ARC, FACTOR, and PLANE. Only two of these are necessary: ARC, PLANE. This commit removes SLOPPY_ARC, and FACTOR and cleans up the way Geo distance is computed.
Implemented by wrapping an array of reused `ModuleDateTime`s that
we grow when needed. The `ModuleDateTime`s are reused when we
move to the next document.
Also improves the error message returned when attempting to modify
the `ScriptdocValues`, removes a couple of allocations, and documents
that the date functions are available in Painless.
Relates to #22162
Currently, stored scripts use a namespace of (lang, id) to be put, get, deleted, and executed. This is not necessary since the lang is stored with the stored script. A user should only have to specify an id to use a stored script. This change makes that possible while keeping backwards compatibility with the previous namespace of (lang, id). Anywhere the previous namespace is used will log deprecation warnings.
The new behavior is the following:
When a user specifies a stored script, that script will be stored under both the new namespace and old namespace.
Take for example script 'A' with lang 'L0' and data 'D0'. If we add script 'A' to the empty set, the scripts map will be ["A" -- D0, "A#L0" -- D0]. If a script 'A' with lang 'L1' and data 'D1' is then added, the scripts map will be ["A" -- D1, "A#L1" -- D1, "A#L0" -- D0].
When a user deletes a stored script, that script will be deleted from both the new namespace (if it exists) and the old namespace.
Take for example a scripts map with {"A" -- D1, "A#L1" -- D1, "A#L0" -- D0}. If a script is removed specified by an id 'A' and lang null then the scripts map will be {"A#L0" -- D0}. To remove the final script, the deprecated namespace must be used, so an id 'A' and lang 'L0' would need to be specified.
When a user gets/executes a stored script, if the new namespace is used then the script will be retrieved/executed using only 'id', and if the old namespace is used then the script will be retrieved/executed using 'id' and 'lang'
* Integrate UnifiedHighlighter
This change integrates the Lucene highlighter called "unified" in the list of supported highlighters for ES.
This highlighter can extract offsets from either postings, term vectors, or via re-analyzing text.
The best strategy is picked automatically at query time and depends on the field and the query to highlight.
Added missing CONSOLE scripts to documentation for sampler and diversified_sampler aggs.
Includes new StackOverflow index setup in build.gradle
Closes#22746
* Formatting tweaks
This change removes the ability to set region for s3 repositories.
Endpoint should be used instead if a custom s3 location needs to be
used.
closes#22758
Follow up of #22857 where we deprecate automatic creation of azure containers.
BTW I found that the `AzureSnapshotRestoreServiceIntegTests` does not bring any value because it runs basically a Snapshot/Restore operation on local files which we already test in core.
So instead of trying to fix it to make it pass with this PR, I simply removed it.
Adds "Appending B. Painless API Reference", a reference of all classes
and methods available from Painless. Removes links to java packages
because they contain methods that we don't expose and don't contain
methods that we do expose (the ones in Augmentation). Instead this
generates a list of every class and every exposed method using the same
type information available to the
interpreter/compiler/whatever-we-call-it. From there you can jump to
the relevant docs.
Right now you build all the asciidoc files by running
```
gradle generatePainlessApi
```
These files are expected to be committed because we build the docs
without running `gradle`.
Also changes the output of `Debug.explain` so that it is easy to
search for the class in the generated reference documentation.
You can also run it in an IDE safely if you pass the path to the
directory in which to generate the docs as the first parameter. It'll
blow away the entire directory an recreate it from scratch so be careful.
And then you can build the docs by running something like:
```
../docs/build_docs.pl --out ../built_docs/ --doc docs/reference/index.asciidoc --open
```
That is, if you have checked out https://github.com/elastic/docs in
`../docs`. Wait a minute or two and your browser will pop open in with
all of Elasticsearch's reference documentation. If you go to
`http://localhost:8000/painless-api-reference.html` you can see this
list. Or you can get there by following the links to `Modules` and
`Scripting` and `Painless` and then clicking the link in the paragraphs
below titled `Appendix B. Painless API Reference`.
I like having these in asciidoc because we can deep link to them from the
rest of the guide with constructs like
`<<painless-api-reference-Object-hashCode-0>>` and
`<<painless-api-reference->>` and we get link checking. Then the only
brittle link maintenance bit is the link generation for javadoc. Which
sucks. But I think it is important that we link to the methods directly
so they are easy to find.
Relates to #22720
Add unit tests for `TopHitsAggregator` and convert some snippets in
docs for `top_hits` aggregation to `// CONSOLE`.
Relates to #22278
Relates to #18160
There was a typo in the `ParseField` declaration. I know
we want to port these parsers to `ObjectParser` eventually
but I don't have the energy for that today and want to get
this fixed.
Closes#22722
When users need to specify a custom location for configuration files,
they also need to specify a custom location for the jvm.options file yet
our docs are absent in this regard. This commit adds a note to the
rolling upgrade docs explaining this situation.
Relates #22747
* Add top hits collapsing to search request
The field collapsing is done with a custom top docs collector that "collapse" search hits with same field value.
The distributed aspect is resolve using the two passes that the regular search uses. The first pass "collapse" the top hits, then the coordinating node merge/collapse the top hits from each shard.
```
GET _search
{
"collapse": {
"field": "category",
}
}
```
This change also adds an ExpandCollapseSearchResponseListener that intercepts the search response and expands collapsed hits using the CollapseBuilder#innerHit} options.
The retrieval of each inner_hits is done by sending a query to all shards filtered by the collapse key.
```
GET _search
{
"collapse": {
"field": "category",
"inner_hits": {
"size": 2
}
}
}
```
Adds the `VIEW IN CONSOLE` and `COPY AS CURL` links to the snippets
in the `value_count` docs and causes the build to execute the snippets
for testing.
Release #18160
This adds the `VIEW IN CONSOLE` and `COPY AS CURL` links to the
snippets in the docs for the `date_range` aggregation and tests
those snippets as part of the build.
Relates to #18160
This adds the `VIEW IN SENSE` and `COPY AS CURL` links and has
the build automatically execute the snippets and verify that they
work.
Relates to #18160
Adds the `VIEW IN CONSOLE` and `COPY AS CURL` links to the example
`global` aggregation. Also improves the example by adding a
non-`global` aggregation to compare it to.
Relates to #18160
Similar to the Filters aggregation but only supports "keyed" filter buckets and automatically "ANDs" pairs of filters to produce a form of adjacency matrix.
The intersection of buckets "A" and "B" is named "A&B" (the choice of separator is configurable). Empty intersection buckets are removed from the final results.
Closes#22169
This PR removes all leniency in the conversion of Strings to booleans: "true"
is converted to the boolean value `true`, "false" is converted to the boolean
value `false`. Everything else raises an error.
Relates to #22024
On top of documentation, the PR adds deprecation loggers and deals with the resulting warning headers.
The yaml test is set exclude versions up to 6.0. This is need to make sure bwc tests pass until this is backported to 5.2.0 . Once that's done, I will change the yaml test version limits
This change makes it possible for custom routing values to go to a subset of shards rather than
just a single shard. This enables the ability to utilize the spatial locality that custom routing can
provide while mitigating the likelihood of ending up with an imbalanced cluster or suffering
from a hot shard.
This is ideal for large multi-tenant indices with custom routing that suffer from one or both of
the following:
- The big tenants cannot fit into a single shard or there is so many of them that they will likely
end up on the same shard
- Tenants often have a surge in write traffic and a single shard cannot process it fast enough
Beyond that, this should also be useful for use cases where most queries are done under the context
of a specific field (e.g. a category) since it gives a hint at how the data can be stored to minimize
the number of shards to check per query. While a similar solution can be achieved with multiple
concrete indices or aliases per value today, those approaches breakdown for high cardinality fields.
A partitioned index enforces that mappings have routing required, that the partition size does not
change when shrinking an index (the partitions will shrink proportionally), and rejects mappings
that have parent/child relationships.
Closes#21585
This commit corrects the grammar in a list in the how-to docs; namely,
the word "and" was missing preceding the final element in a list.
Relates #22663
* Grammatical correction
* Add note for legacy string mapping type
* Update truncate token filter to not mention the keyword tokenizer
The advice predates the existence of the keyword field
Closes#22650