Restoring IoTDB Metadata

Scenarios

To ensure IoTDB metadata security and prevent the IoTDB service from being unavailable due to IoTDB file damage, IoTDB metadata needs to be backed up. In this way, the system can restore data timely when an exception is reported or an operation does not achieve the expected result, minimizing the impact on services.

System administrators can create an IoTDB restoration task on FusionInsight Manager. Only manual restoration tasks are supported.

• Data restoration can be performed only when the system version is consistent with the version used during data backup.
• To restore data when the service is running properly, it is recommended that you manually back up the latest management data before performing data restoration. Otherwise, the IoTDB data that is generated after the data backup and before the data restoration will be lost.
• It is recommended that each data restoration task restore the metadata of only one component to avoid affecting the restoration of other components when a service or instance is stopped. If data of multiple components is restored at the same time, data restoration may fail.

Impact on the System

After the metadata is restored, the data generated after the data backup and before the data restoration is lost.

Restoring IoTDB Metadata

1. Log in to MRS Manager.

   For details about how to log in to MRS Manager, see Accessing MRS Manager.

2. Choose O&M > Backup and Restoration > Backup Management.
3. In the row containing the specified backup task, choose More > View History in the Operation column to display the task's historical execution records.

   In the displayed window, locate the desired success record and click View in the Backup Path column to display the task's backup path information and obtain the following details:

   • Backup Object: indicates the backup data source.
   • Backup Path: indicates the full path where the backup files are stored.

     Locate the correct path, and manually copy the full path of the backup files from the Backup Path column.

4. On FusionInsight Manager, choose O&M > Backup and Restoration > Restoration Management.
5. Click Create.
6. Set Task Name to the name of the restoration task.
7. Select the cluster to be operated from Recovery Object.
8. In Restoration Configuration, select IoTDB under Metadata and other data.
9. Select a backup directory type for Path Type.

   The configurations vary based on backup directory types:

   • LocalDir: indicates that the backup files are stored on the local disk of the active management node.

     If you select this option, you also need to set Source Path, which indicates the backup file to be restored, for example, Version_Data source_Task execution time.tar.gz.

   • NFS: indicates that backup files are stored in NAS using the NFS protocol.
     If you select this option, configure the following parameters:

     • IP Mode: indicates the IP version of the target IP address. The system automatically determines the IP version, such as IPv4 or IPv6, based on the cluster network type.

     • Server IP Address: indicates the IP address of the NAS server.
     • Source Path: indicates the complete path of the backup file on the NAS server, for example, Backup path/Backup task name_Data source_Task creation time/Version_Data source_Task execution time.tar.gz.
   • RemoteHDFS: indicates that the backup files are stored in the HDFS directory of the standby cluster.
     If you select this option, configure the following parameters:

     • Source NameService Name: indicates the NameService name of the backup data cluster, for example, hacluster. You can obtain it from the NameService Management page of HDFS in the standby cluster.
     • IP Mode: indicates the IP version of the target IP address. The system automatically determines the IP version, such as IPv4 or IPv6, based on the cluster network type.
     • Source Active NameNode IP Address: indicates the service plane IP address of the active NameNode in the standby cluster.
     • Source Standby NameNode IP Address: indicates the service plane IP address of the standby NameNode in the standby cluster.
     • Source NameNode RPC Port: indicates the value of dfs.namenode.rpc.port in the HDFS basic configuration of the standby cluster.
     • Source Path: indicates the full path of HDFS directory for storing backup data of the standby cluster, for example, Backup path/Backup task name_Data source_Task creation time/Version_Data source_Task execution time.tar.gz.
   • CIFS: indicates that backup files are stored in NAS using the CIFS protocol.
     If you select this option, configure the following parameters:

     • IP Mode: indicates the IP version of the target IP address. The system automatically determines the IP version, such as IPv4 or IPv6, based on the cluster network type.

     • Server IP Address: indicates the IP address of the NAS server.
     • Port: indicates the port number used to connect to the NAS server over the CIFS protocol. The default value is 445.
     • Username: indicates the username set when the CIFS protocol is configured.
     • Password: indicates the password set when the CIFS protocol is configured.
     • Source Path: indicates the complete path of the backup file on the NAS server, for example, Backup path/Backup task name_Data source_Task creation time/Version_Data source_Task execution time.tar.gz.
   • SFTP: indicates that backup files are stored in the server using the SFTP protocol.
     If you select this option, configure the following parameters:

     • IP Mode: indicates the IP version of the target IP address. The system automatically determines the IP version, such as IPv4 or IPv6, based on the cluster network type.

     • Server IP Address: indicates the IP address of the server where the backup data is stored.
     • Port: indicates the port number used to connect to the backup server over the SFTP protocol. The default value is 22.
     • Username: indicates the username for connecting to the server using the SFTP protocol.
     • Password: indicates the password for connecting to the server using the SFTP protocol.
     • Source Path: indicates the complete path of the backup file on the backup server, for example, Backup path/Backup task name_Data source_Task creation time/Version_Data source_Task execution time.tar.gz.

10. Click OK.
11. In the restoration task list, locate the row containing the created task, and click Start in the Operation column to execute the restoration task.
    • After the restoration is successful, the progress bar is in green.
    • After the restoration is successful, the restoration task cannot be executed again.
    • If the restoration task fails during the first execution, rectify the fault and click Retry to execute the task again.

12. Choose Cluster > Services and start the IoTDB service.