[Doc] Update Meta Recovery (backport #51661) (#51783)

Co-authored-by: 絵空事スピリット <[email protected]>

docs/en/administration/Meta_recovery.md

@@ -14,6 +14,7 @@ Generally, you may have to resort to metadata recovery when and only when one of
 
 - [FE fails to restart](#fe-fails-to-restart)
 - [FE fails to provide services](#fe-fails-to-provide-services)
+- [Recover metadata on a new FE node with the metadata backup](#recover-metadata-on-a-new-fe-node-with-metadata-backup).
 
 Check the issue you encountered, follow the solution provided in the corresponding section, and perform any recommended actions.
 
@@ -124,7 +125,7 @@ You can follow these steps to fix this issue:
    ALTER SYSTEM DROP FOLLOWER "<follower_host>:<follower_edit_log_port>";
 
    -- To drop an Observer node, replace <observer_host> with the IP address (priority_networks) 
-   -- of the Oberver node, and replace <observer_edit_log_port> (Default: 9010) with 
+   -- of the Observer node, and replace <observer_edit_log_port> (Default: 9010) with 
    -- the Observer node's edit_log_port.
    ALTER SYSTEM DROP OBSERVER "<observer_host>:<observer_edit_log_port>";
    ```
@@ -540,7 +541,7 @@ Follow these steps to recover the metadata:
 
     </TabItem>
 
-    <TabItem value="oberserver" label="Proceed with Observer Node" >
+    <TabItem value="observer" label="Proceed with Observer Node" >
 
    If an Observer node has the latest metadata, perform the following operations:
 
@@ -579,7 +580,7 @@ Follow these steps to recover the metadata:
       ALTER SYSTEM DROP FOLLOWER "<follower_host>:<follower_edit_log_port>";
 
       -- To drop an Observer node, replace <observer_host> with the IP address (priority_networks) 
-      -- of the Oberver node, and replace <observer_edit_log_port> (Default: 9010) with 
+      -- of the Observer node, and replace <observer_edit_log_port> (Default: 9010) with 
       -- the Observer node's edit_log_port.
       ALTER SYSTEM DROP OBSERVER "<observer_host>:<observer_edit_log_port>";
       ```
@@ -649,7 +650,7 @@ Follow these steps to recover the metadata:
    ALTER SYSTEM DROP FOLLOWER "<follower_host>:<follower_edit_log_port>";
 
    -- To drop an Observer node, replace <observer_host> with the IP address (priority_networks) 
-   -- of the Oberver node, and replace <observer_edit_log_port> (Default: 9010) with 
+   -- of the Observer node, and replace <observer_edit_log_port> (Default: 9010) with 
    -- the Observer node's edit_log_port.
    ALTER SYSTEM DROP OBSERVER "<observer_host>:<observer_edit_log_port>";
    ```
@@ -672,6 +673,44 @@ Follow these steps to recover the metadata:
 
 After all nodes are added back to the cluster, the metadata is successfully recovered.
 
+## Recover metadata on a new FE node with metadata backup
+
+Follow these steps if you want to start a new FE node with the metadata backup:
+
+1. Copy the backup metadata directory `meta_dir` to the new FE node.
+2. In the configuration file of the FE node, set `bdbje_reset_election_group` to `true`.
+
+   ```Properties
+   bdbje_reset_election_group = true
+   ````
+
+3. Start the FE node.
+
+   ```Bash
+   # Replace <fe_ip> with the IP address (priority_networks) 
+   # of the new FE node, and replace <fe_edit_log_port> (Default: 9010) with 
+   # the new FE node's edit_log_port.
+   ./fe/bin/start_fe.sh --helper <fe_ip>:<fe_edit_log_port> --daemon
+   ```
+
+4. Check whether the current FE node is the Leader FE node.
+
+   ```SQL
+   SHOW FRONTENDS;
+   ```
+
+   If the field `Role` is `LEADER`, this FE node is the Leader FE node. Make sure its IP address is the that of the current FE node.
+
+5. If the data and metadata are intact, and the role of the node is Leader, you must remove the configuration `bdbje_reset_election_group` and restart the node.
+6. Now you have successfully start a new Leader FE node with the metadata backup. You can add new Follower nodes using the new Leader FE node as the helper.
+
+   ```Bash
+   # Replace <leader_ip> with the IP address (priority_networks) 
+   # of the Leader FE node, and replace <leader_edit_log_port> (Default: 9010) with 
+   # the Leader FE node's edit_log_port.
+   ./fe/bin/start_fe.sh --helper <leader_ip>:<leader_edit_log_port> --daemon
+   ```
+
 ## Metadata recovery-related configurations
 
 :::tip

docs/zh/administration/Meta_recovery.md

@@ -14,6 +14,7 @@ import TabItem from '@theme/TabItem';
 
 - [FE 节点无法启动](#fe-节点无法启动)
 - [FE 节点无法提供服务](#fe-节点无法提供服务)
+- [基于备份在新 FE 节点恢复元数据](#基于备份在新-fe-节点恢复元数据)
 
 请排查您所遇到的问题，并按照对应解决方案进行操作。建议按照文中推荐的操作执行。
 
@@ -538,7 +539,7 @@ jstat -gcutil pid 1000 1000
 
     </TabItem>
 
-    <TabItem value="oberserver" label="从 Observer 节点恢复" >
+    <TabItem value="observer" label="从 Observer 节点恢复" >
 
    如果元数据最新的节点为 Observer，则执行以下操作：
 
@@ -664,6 +665,42 @@ jstat -gcutil pid 1000 1000
 
 当所有节点都重新添加到集群后，元数据恢复成功。
 
+## 基于备份在新 FE 节点恢复元数据
+
+如果要使用元数据备份启动新的 FE 节点，请按照以下步骤操作：
+
+1. 将备份的元数据路径 `meta_dir` 复制至新的 FE 节点。
+2. 在该 FE 节点的配置文件中添加配置项 `bdbje_reset_election_group` 为 `true`。
+
+   ```Properties
+   bdbje_reset_election_group = true
+   ````
+
+3. 启动该 FE 节点。
+
+   ```Bash
+   # 将 <fe_ip> 替换为新 FE 节点的 IP 地址（priority_networks），
+   # 并将 <fe_edit_log_port>（默认：9010）替换为新 FE 节点的 edit_log_port。
+   ./fe/bin/start_fe.sh --helper <fe_ip>:<fe_edit_log_port> --daemon
+   ```
+
+4. 查看当前节点是否为 Leader 节点。
+
+   ```SQL
+   SHOW FRONTENDS;
+   ```
+
+   如果字段 `Role` 为 `LEADER`，说明该 FE 节点为 Leader FE 节点。确保返回的是当前 FE 节点的 IP 地址。
+
+5. 如果数据和元数据完整，且该节点的角色是 Leader 后，需要删除之前添加的配置项 `bdbje_reset_election_group` 并重新启动节点。
+6. 现在，您已成功通过元数据备份启动了新的 Leader FE 节点。您可以使用新 Leader FE 节点作为 Helper 添加 Follower 节点。
+
+   ```Bash
+   # 将 <leader_ip> 替换为 Leader FE 节点的 IP 地址（priority_networks），
+   # 并将 <leader_edit_log_port>（默认：9010）替换为 Leader FE 节点的 edit_log_port。
+   ./fe/bin/start_fe.sh --helper <leader_ip>:<leader_edit_log_port> --daemon
+   ```
+
 ## 元数据恢复相关配置
 
 :::tip