doc: add metaCacheMaxSize description

docs/en/14-reference/12-config/index.md

@@ -365,6 +365,16 @@ The charset that takes effect is UTF-8.
 | Unit          | GB                                                                                                |
 | Default Value | 2.0                                                                                               |
 
+### metaCacheMaxSize
+
+| Attribute     | Description                                                                                       |
+| ------------- | ------------------------------------------------------------------------------------------------- |
+| Applicable    | Client Only                                                                                       |
+| Meaning       | Maximum meta cache size in single client process                                                  |
+| Unit          | MB                                                                                                |
+| Default Value | -1 (No limitation)                                                                                |
+
+
 ## Cluster Parameters
 
 ### supportVnodes

docs/zh/14-reference/12-config/index.md

@@ -384,6 +384,15 @@ charset 的有效值是 UTF-8。
 | 单位     | GB                                             |
 | 缺省值   | 2.0                                            |
 
+### metaCacheMaxSize
+
+| 属性     | 说明                                           |
+| -------- | ---------------------------------------------- |
+| 适用范围 | 仅客户端适用                                   |
+| 含义     | 指定单个客户端元数据缓存大小的最大值           |
+| 单位     | MB                                             |
+| 缺省值   | -1 (无限制)                                    |
+
 ## 集群相关
 
 ### supportVnodes