[DOCS] Add data streams to put mapping and update settings API docs (#58849)

docs/reference/indices/put-mapping.asciidoc

@@ -4,8 +4,10 @@
 <titleabbrev>Put mapping</titleabbrev>
 ++++
 
-Adds new fields to an existing index or changes the search settings of existing
-fields.
+Adds new fields to an existing data stream or index. You can also use the
+put mapping API to change the search settings of existing fields.
+
+For data streams, these changes are applied to all backing indices by default.
 
 [source,console]
 ----
@@ -23,7 +25,7 @@ PUT /twitter/_mapping
 [[put-mapping-api-request]]
 ==== {api-request-title}
 
-`PUT /<index>/_mapping`
+`PUT /<target>/_mapping`
 
 `PUT /_mapping`
 
@@ -31,10 +33,13 @@ PUT /twitter/_mapping
 [[put-mapping-api-path-params]]
 ==== {api-path-parms-title}
 
-include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=index]
+`<target>`::
+(Optional, string)
+Comma-separated list of data streams, indices, and index aliases used to limit
+the request. Wildcard expressions (`*`) are supported.
 +
-To update the mapping of all indices, omit this parameter or use a value of
-`_all`.
+To target all data streams and indices in a cluster, omit this parameter or use
+`_all` or `*`.
 
 
 [[put-mapping-api-query-params]]
@@ -74,9 +79,9 @@ For existing fields, see <<updating-field-mappings>>.
 ==== {api-examples-title}
 
 [[put-field-mapping-api-basic-ex]]
-===== Example with index setup
+===== Example with single target
 
-The put mapping API requires an existing index. The following
+The put mapping API requires an existing data stream or index. The following
 <<indices-create-index, create index>> API request creates the `publications`
 index with no mapping.
 
@@ -100,10 +105,10 @@ PUT /publications/_mapping
 // TEST[continued]
 
 [[put-mapping-api-multi-ex]]
-===== Multiple indices
+===== Multiple targets
 
-The PUT mapping API can be applied to multiple indices with a single request.
-For example, we can update the `twitter-1` and `twitter-2` mappings at the same time:
+The PUT mapping API can be applied to multiple data streams or indices with a single request.
+For example, you can update mappings for the `twitter-1` and `twitter-2` indices at the same time:
 
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 --------------------------------------------------
@@ -392,12 +397,15 @@ Except for supported <<mapping-params,mapping parameters>>,
 you can't change the mapping or field type of an existing field.
 Changing an existing field could invalidate data that's already indexed.
 
-If you need to change the mapping of a field,
+If you need to change the mapping of a field in a data stream's backing indices,
+see <<data-streams-change-mappings-and-settings>>. 
+
+If you need to change the mapping of a field in other indices,
 create a new index with the correct mapping
 and <<docs-reindex,reindex>> your data into that index.
 // end::change-field-mapping[]
 
-To see how this works,
+To see how you can change the mapping of an existing field in an index,
 try the following example.
 
 Use the <<indices-create-index,create index>> API

docs/reference/indices/update-settings.asciidoc

@@ -4,7 +4,10 @@
 <titleabbrev>Update index settings</titleabbrev>
 ++++
 
-Changes an <<index-modules-settings,index setting>> in real time.
+Changes a <<index-modules-settings,dynamic index setting>> in real time.
+
+For data streams, index setting changes are applied to all backing indices by
+default.
 
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 --------------------------------------------------
@@ -21,16 +24,19 @@ PUT /twitter/_settings
 [[update-index-settings-api-request]]
 ==== {api-request-title}
 
-`PUT /<index>/_settings`
+`PUT /<target>/_settings`
 
 
 [[update-index-settings-api-path-params]]
 ==== {api-path-parms-title}
 
-include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=index]
+`<target>`::
+(Optional, string)
+Comma-separated list of data streams, indices, and index aliases used to limit
+the request. Wildcard expressions (`*`) are supported.
 +
-To update a setting for all indices,
-use `_all` or exclude this parameter.
+To target all data streams and indices in a cluster, omit this parameter or use
+`_all` or `*`.
 
 
 [[update-index-settings-api-query-params]]
@@ -138,8 +144,26 @@ To add an analyzer,
 you must close the index,
 define the analyzer,
 and reopen the index.
+
+[NOTE]
+====
+You cannot close the write index of a data stream. 
+
+To update the analyzer for a data stream's write index and future backing
+indices, update the analyzer in the <<create-a-data-stream-template,index
+template used by the stream>>. Then <<manually-roll-over-a-data-stream,roll over
+the data stream>> to apply the new analyzer to the stream’s write index and
+future backing indices. This affects searches and any new data added to the
+stream after the rollover. However, it does not affect the data stream's backing
+indices or their existing data.
+
+To change the analyzer for existing backing indices, you must create a
+new data stream and reindex your data into it. See
+<<data-streams-use-reindex-to-change-mappings-settings>>.
+====
+
 For example,
-the following commands add the `content` analyzer to `myindex`:
+the following commands add the `content` analyzer to the `twitter` index:
 
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