Update s3-repository docs after upgrade (#1356)

These changes are to bring the docs into alignment with the changes made
as part of the S3 upgrade
elastic/elasticsearch#126843

---------

Co-authored-by: David Turner <[email protected]>
Co-authored-by: Edu González de la Herrán <[email protected]>

Author: 3 people

deploy-manage/tools/snapshot-and-restore/s3-repository.md

@@ -79,6 +79,9 @@ Define the relevant secure settings in each node’s keystore before starting th
 
 The following list contains the available client settings. Those that must be stored in the keystore are marked as "secure" and are **reloadable**; the other settings belong in the [`elasticsearch.yml`](/deploy-manage/stack-settings.md) file.
 
+`region`
+:   Specifies the region to use. When set, determines the signing region and regional endpoint to use, unless the endpoint is overridden via the `endpoint` setting. If not set, {{es}} will attempt to determine the region automatically using the AWS SDK.
+
 `access_key` ([Secure](/deploy-manage/security/secure-settings.md), [reloadable](../../security/secure-settings.md#reloadable-secure-settings))
 :   An S3 access key. If set, the `secret_key` setting must also be specified. If unset, the client will use the instance or container role instead.
 
@@ -89,10 +92,12 @@ The following list contains the available client settings. Those that must be st
 :   An S3 session token. If set, the `access_key` and `secret_key` settings must also be specified.
 
 `endpoint`
-:   The S3 service endpoint to connect to. This defaults to `s3.amazonaws.com` but the [AWS documentation](https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region) lists alternative S3 endpoints. If you are using an [S3-compatible service](#repository-s3-compatible-services) then you should set this to the service’s endpoint.
+:   The S3 service endpoint to connect to. This defaults to the regional endpoint corresponding to the configured `region`, but the [AWS documentation](https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region) lists alternative S3 endpoints. If you are using an [S3-compatible service](#repository-s3-compatible-services) then you should set this to the service’s endpoint. The endpoint should specify the protocol and host name, e.g. `https://s3.ap-southeast-4.amazonaws.com`, `http://minio.local:9000`.
+
+    When using HTTPS, this repository type validates the repository’s certificate chain using the JVM-wide truststore. Ensure that the root certificate authority is in this truststore using the JVM’s `keytool` tool. If you have a custom certificate authority for your S3 repository and you use the {{es}} [bundled JDK](../../deploy/self-managed/installing-elasticsearch.md#jvm-version), then you will need to reinstall your CA certificate every time you upgrade {{es}}.
 
 `protocol`
-:   The protocol to use to connect to S3. Valid values are either `http` or `https`. Defaults to `https`. When using HTTPS, this repository type validates the repository’s certificate chain using the JVM-wide truststore. Ensure that the root certificate authority is in this truststore using the JVM’s `keytool` tool. If you have a custom certificate authority for your S3 repository and you use the {{es}} [bundled JDK](../../deploy/self-managed/installing-elasticsearch.md#jvm-version), then you will need to reinstall your CA certificate every time you upgrade {{es}}.
+:   The protocol to use to connect to S3. Valid values are either `http` or `https`. Defaults to `https`. Note that this setting is deprecated since 8.19 and is only used if `endpoint` is set to a URL that does not include a scheme. Users should migrate to including the scheme in the `endpoint` setting. 
 
 `proxy.host`
 :   The host name of a proxy to connect to S3 through.
@@ -118,9 +123,6 @@ The following list contains the available client settings. Those that must be st
 `max_retries`
 :   The number of retries to use when an S3 request fails. The default value is `3`.
 
-`use_throttle_retries`
-:   Whether retries should be throttled (i.e. should back off). Must be `true` or `false`. Defaults to `true`.
-
 `path_style_access`
 :   Whether to force the use of the path style access pattern. If `true`, the path style access pattern will be used. If `false`, the access pattern will be automatically determined by the AWS Java SDK (See [AWS documentation](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Builder.html#setPathStyleAccessEnabled-java.lang.Boolean-) for details). Defaults to `false`.
 
@@ -134,12 +136,6 @@ In versions `7.0`, `7.1`, `7.2` and `7.3` all bucket operations used the [now-de
 `disable_chunked_encoding`
 :   Whether chunked encoding should be disabled or not. If `false`, chunked encoding is enabled and will be used where appropriate. If `true`, chunked encoding is disabled and will not be used, which may mean that snapshot operations consume more resources and take longer to complete. It should only be set to `true` if you are using a storage service that does not support chunked encoding. See the [AWS Java SDK documentation](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Builder.html#disableChunkedEncoding--) for details. Defaults to `false`.
 
-`region`
-:   Allows specifying the signing region to use. Specificing this setting manually should not be necessary for most use cases. Generally, the SDK will correctly guess the signing region to use. It should be considered an expert level setting to support S3-compatible APIs that require [v4 signatures](https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html) and use a region other than the default `us-east-1`. Defaults to empty string which means that the SDK will try to automatically determine the correct signing region.
-
-`signer_override`
-:   Allows specifying the name of the signature algorithm to use for signing requests by the S3 client. Specifying this setting should not be necessary for most use cases. It should be considered an expert level setting to support S3-compatible APIs that do not support the signing algorithm that the SDK automatically determines for them. See the [AWS Java SDK documentation](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/ClientConfiguration.html#setSignerOverride-java.lang.String-) for details. Defaults to empty string which means that no signing algorithm override will be used.
-
 
 ## Repository settings [repository-s3-repository]