Restoring Hive Service Data

Scenario

Hive data needs to be recovered in the following scenarios: data is modified or deleted unexpectedly and needs to be restored. After an administrator performs critical data adjustment in the Hive, an exception occurs or the operation has not achieved the expected result. All modules are faulty and become unavailable. Data is migrated to a new cluster.

System administrators can create a recovery task in FusionInsight Manager to recover Hive data. Only manual restoration tasks are supported.

Hive backup and restoration cannot identify the service and structure relationships of objects such as Hive tables, indexes, and views. When executing backup and restoration tasks, you need to manage unified restoration points based on service scenarios to ensure proper service running.

• Data restoration can be performed only when the system version is consistent with that during data backup.
• To recover data when the service is running properly, you are advised to manually back up the latest management data before recovering data. Otherwise, the Hive data that is generated after the data backup and before the data recovery will be lost.

Impact on the System

• During data restoration, user authentication stops and users cannot create new connections.
• After the data is restored, the data generated after the data backup and before the data restoration is lost.
• After the data is recovered, the Hive upper-layer applications need to be started.

Prerequisites

• If you need to restore data from a remote HDFS, a standby cluster has been created and the data has been backed up. For details, see Backing Up Hive Service Data. If the active cluster is deployed in security mode and the active and standby clusters are not managed by the same FusionInsight Manager, mutual trust has been configured. For details, see Configuring Mutual Trust Between MRS Clusters. If the active cluster is deployed in normal mode, no mutual trust is required.

• Cross-cluster replication has been configured for the active and standby clusters. For details, see Enabling MRS Inter-Cluster Replication.
• Time is consistent between the active and standby clusters and the NTP services on the active and standby clusters use the same time source.
• The database for storing restored data tables, the HDFS save path of data tables, and the list of users who can access restored data are planned.
• The Hive backup file save path is correct.
• The Hive upper-layer applications are stopped.

Restoring Hive Service Data

1. On FusionInsight Manager, choose O&M > Backup and Restoration > Backup Management.
2. In the Operation column of a specified task in the task list, choose More > View History to view historical backup task execution records.

   In the displayed window, locate a specified success record and click View in the Backup Path column to view the backup path information of the task and find the following information:

   • Backup Object specifies the data source of the backup data.
   • Backup Path specifies the full path where the backup files are saved.

     Select the correct item, and manually copy the full path of backup files in Backup Path.

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

   The following backup directory types are supported:

   • RemoteHDFS: indicates that the backup files are stored in the HDFS directory of the standby cluster. If you select RemoteHDFS, set the following parameters:
     • Source NameService Name: indicates the NameService name of the backup data cluster. You can enter the built-in NameService name of the remote cluster, for example, haclusterX, haclusterX1, haclusterX2, haclusterX3, or haclusterX4. You can also enter a configured NameService name of the remote cluster.
     • IP Mode: indicates the mode of the target IP address. The system automatically selects the IP address mode based on the cluster network type, for example, IPv4 or IPv6.
     • Source NameNode IP Address: indicates the NameNode service plane IP address of the standby cluster, supporting the active node or standby node.
     • 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.
     • Queue Name: indicates the name of the Yarn queue used for backup task execution.
     • Recovery Point List: Click Refresh and select a Hive backup file set that has been backed up in the standby cluster.
     • Target NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value is 100.
   • NFS: indicates that backup files are stored in NAS using the NFS protocol. If you select NFS, set the following parameters:
     • IP Mode: indicates the mode of the target IP address. The system automatically selects the IP address mode based on the cluster network type, for example, IPv4 or IPv6.
     • Server IP Address: indicates the IP address of the NAS server.
     • Source Path: indicates the full path of the backup file on the NAS server, for example, Backup path/Backup task name_Data source_Task creation time.
     • Queue Name: indicates the name of the Yarn queue used for backup task execution.
     • Recovery Point List: Click Refresh and select a Hive backup file set that has been backed up in the standby cluster.
     • Target NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value is 100.
   • CIFS: indicates that backup files are stored in NAS using the CIFS protocol. If you select CIFS, set the following parameters:
     • IP Mode: indicates the mode of the target IP address. The system automatically selects the IP address mode based on the cluster network type, for example, IPv4 or IPv6.
     • 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 full path of the backup file on the NAS server, for example, Backup path/Backup task name_Data source_Task creation time.
     • Queue Name: indicates the name of the Yarn queue used for backup task execution.
     • Recovery Point List: Click Refresh and select a Hive backup file set that has been backed up in the standby cluster.
     • Target NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value is 100.
   • SFTP: indicates that backup files are stored in the server using the SFTP protocol.
     If you select SFTP, set the following parameters:

     • IP Mode: indicates the mode of the target IP address. The system automatically selects the IP address mode based on the cluster network type, for example, IPv4 or IPv6.

     • 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 full path of the backup file on the backup server, for example, Backup path/Backup task name_Data source_Task creation time.
     • Queue Name: indicates the name of the Yarn queue used for backup task execution.
     • Recovery Point List: Click Refresh and select an HDFS directory that has been backed up in the standby cluster.
     • Target NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value is 1.

9. Set Backup Data in the Data Configuration to one or multiple backup data sources to be recovered based on service requirements. In the Target Database and Target Path columns, specify the target database and file save path after backup data recovery.

   Configuration restrictions:

   • Data can be restored to the original database, but data tables must be stored in a new path that is different from the backup path.
   • To restore Hive index tables, select the Hive data tables that correspond to the Hive index tables to be restored.
   • If a new restoration directory is selected to avoid affecting the current data, HDFS permission must be manually granted so that users who have permission of backup tables can access this directory.
   • Data can be restored to other databases. In this case, HDFS permission must be manually granted so that users who have permission of backup tables can access the HDFS directory that corresponds to the database.

10. Set Force recovery to true, which indicates to forcibly recover all backup data when a data table with the same name already exists. If the data table contains new data added after backup, the new data will be lost after the data recovery. If you set the parameter to false, the restoration task is not executed if a data table with the same name exists.
11. Click Verify to check whether the restoration task is configured correctly.
    • If the queue name is incorrect, the verification fails.
    • If the specified directory to be restored does not exist, the verification fails.
    • If the forcible overwrite conditions are not met, the verification fails.

12. Click OK.
13. In the restoration task list, locate a 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.