docs: remove the note for the default value of key when chash is …

…set as the load balancing algorithm (#10151)

docs/en/latest/admin-api.md

@@ -900,7 +900,7 @@ In addition to the equalization algorithm selections, Upstream also supports pas
 | service_name                | required, can't be used with `nodes`        | Service name used for [service discovery](discovery.md).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         | `a-bootiful-client`                                                                                                                        |
 | discovery_type              | required, if `service_name` is used         | The type of service [discovery](discovery.md).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | `eureka`                                                                                                                                   |
 | hash_on                     | optional                                    | Only valid if the `type` is `chash`. Supports Nginx variables (`vars`), custom headers (`header`), `cookie` and `consumer`. Defaults to `vars`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                            |
-| key                         | optional                                    | Only valid if the `type` is `chash`. Finds the corresponding node `id` according to `hash_on` and `key` values. When `hash_on` is set to `vars`, `key` is a required parameter and it supports [Nginx variables](http://nginx.org/en/docs/varindex.html). When `hash_on` is set as `header`, `key` is a required parameter, and `header name` can be customized. When `hash_on` is set to `cookie`, `key` is also a required parameter, and `cookie name` can be customized. When `hash_on` is set to `consumer`, `key` need not be set and the `key` used by the hash algorithm would be the authenticated `consumer_name`. If the specified `hash_on` and `key` fail to fetch the values, it will default to `remote_addr`. | `uri`, `server_name`, `server_addr`, `request_uri`, `remote_port`, `remote_addr`, `query_string`, `host`, `hostname`, `arg_***`, `arg_***` |
+| key                         | optional                                    | Only valid if the `type` is `chash`. Finds the corresponding node `id` according to `hash_on` and `key` values. When `hash_on` is set to `vars`, `key` is a required parameter and it supports [Nginx variables](http://nginx.org/en/docs/varindex.html). When `hash_on` is set as `header`, `key` is a required parameter, and `header name` can be customized. When `hash_on` is set to `cookie`, `key` is also a required parameter, and `cookie name` can be customized. When `hash_on` is set to `consumer`, `key` need not be set and the `key` used by the hash algorithm would be the authenticated `consumer_name`. | `uri`, `server_name`, `server_addr`, `request_uri`, `remote_port`, `remote_addr`, `query_string`, `host`, `hostname`, `arg_***`, `arg_***` |
 | checks                      | optional                                    | Configures the parameters for the [health check](./tutorials/health-check.md).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |                                                                                                                                            |
 | retries                     | optional                                    | Sets the number of retries while passing the request to Upstream using the underlying Nginx mechanism. Set according to the number of available backend nodes by default. Setting this to `0` disables retry.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |                                                                                                                                            |
 | retry_timeout               | optional                                    | Timeout to continue with retries. Setting this to `0` disables the retry timeout.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                                                            |
@@ -935,7 +935,6 @@ The following should be considered when setting the `hash_on` value:
 - When set to `cookie`, a `key` is required. This key is equal to "cookie\_`key`". The cookie name is case-sensitive.
 - When set to `consumer`, the `key` is optional and the key is set to the `consumer_name` captured from the authentication Plugin.
 - When set to `vars_combinations`, the `key` is required. The value of the key can be a combination of any of the [Nginx variables](http://nginx.org/en/docs/varindex.html) like `$request_uri$remote_addr`.
-- When no value is set for either `hash_on` or `key`, the key defaults to `remote_addr`.
 
 The features described below requires APISIX to be run on [APISIX-Base](./FAQ.md#how-do-i-build-the-apisix-base-environment):
 

docs/zh/latest/admin-api.md

@@ -942,7 +942,6 @@ APISIX 的 Upstream 除了基本的负载均衡算法选择外，还支持对上
 - 设为 `header` 时，`key` 为必传参数，其值为自定义的 Header name，即 "http\_`key`"。
 - 设为 `cookie` 时，`key` 为必传参数，其值为自定义的 cookie name，即 "cookie\_`key`"。请注意 cookie name 是**区分大小写字母**的。例如：`cookie_x_foo` 与 `cookie_X_Foo` 表示不同的 `cookie`。
 - 设为 `consumer` 时，`key` 不需要设置。此时哈希算法采用的 `key` 为认证通过的 `consumer_name`。
-- 如果指定的 `hash_on` 和 `key` 获取不到值时，使用默认值：`remote_addr`。
 
 以下特性需要 APISIX 运行于 [APISIX-Base](./FAQ.md#如何构建-APISIX-Base-环境？)：