Recovering 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 a MRS cluster administrator performs critical data adjustment in 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.

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

Hive backup and recovery cannot identify the service and structure relationships of objects such as Hive tables, indexes, and views. When executing backup and recovery tasks, the user needs to manage a unified recovery point based on the service scenario to ensure proper service running.

• Data recovery can be performed only when the system version is consistent with that of 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 recovery, user authentication stops and users cannot create new connections.
• After the data is recovered, the data produced between the backup time and restoration time is lost.
• After the data is recovered, the Hive upper-layer applications need to be started.

Prerequisites

• To restore data from the remote HDFS, you need to prepare the standby cluster. If the active cluster is deployed in security mode and the active and standby clusters are not managed by the same FusionInsight Manager, configure system mutual trust. For details, see Configuring Cross-Manager Cluster Mutual Trust Relationships. If the active cluster is deployed in normal mode, do not configure mutual trust.

• Cross-cluster replication has been configured for the active and standby clusters. For details, see Enabling Cross-Cluster Replication.
• The time of the active cluster and standby cluster must be the same, and the NTP service in the active and standby clusters must use the same time source.
• Plan the database for storing recovered data tables, the HDFS save path of data tables, and the list of users who can access recovered data.
• The Hive backup file save path is correct.
• The Hive upper-layer applications are stopped.
• You have logged in to FusionInsight Manager. For details, see Logging In to FusionInsight Manager.

Procedure

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, click 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 recovery task.
6. Select the cluster to be operated from Recovery Object.
7. 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 this value, you need to set the following parameters:

     • Source NameService Name: indicates the NameService name of the backup data cluster. You can set it to the NameService name (haclusterX, haclusterX1, haclusterX2, haclusterX3, or haclusterX4) of the built-in remote cluster of the cluster, or the NameService name of a configured remote cluster.
     • IP Mode: 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 the HDFS directory for storing standby cluster backup data. 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 target NameService that corresponds to the selected backup directory. The default value of this parameter is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value of this parameter is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value of this parameter is 100.
   • NFS: indicates that backup files are stored in the NAS over the NFS protocol.
     If you select NFS, set the following parameters:

     • IP Mode: 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 NAS server IP address.
     • 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/.
     • 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 target NameService that corresponds to the selected backup directory. The default value of this parameter is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value of this parameter is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value of this parameter is 100.
   • CIFS: indicates that backup files are stored in the NAS over the CIFS protocol.
     If you select CIFS, set the following parameters:

     • IP Mode: 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 NAS server IP address.
     • Port: indicates the port ID used by the CIFS protocol to connect to the NAS server. The default value is 445.
     • Username: Indicates the user name that is configured when setting the CIFS protocol.
     • Password: indicates the password that is configured when setting the CIFS protocol.
     • 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/.
     • 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 target NameService that corresponds to the selected backup directory. The default value of this parameter is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value of this parameter is 20.
   • SFTP: Indicates that backup files are stored in the server using SFTP.
     If you select SFTP, set the following parameters:

     • IP Mode: 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: Enter the IP address of the server where the backup data is stored.
     • Port: Enter the port number used by the SFTP protocol to connect to the backup server. The default value is 22.
     • Username: Enter the username for connecting to the server using SFTP.
     • Password: Enter the password for connecting to the server using SFTP.
     • Source Path: Enter 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 target NameService that corresponds to the selected backup directory. The default value of this parameter is hacluster.
     • Maximum Number of Maps: indicates the maximum number of maps in a MapReduce task. The default value of this parameter is 20.
     • Maximum Bandwidth of a Map (MB/s): indicates the maximum bandwidth of a map. The default value of this parameter 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 recovered to the original database, but data tables must be stored in a new path that is difference from the backup path.
   • To recover Hive index tables, select the Hive data tables that correspond to the Hive index tables to be recovered.
   • If a new recovery 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 recovered 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 YES, 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 NO, the recovery task is not executed if a data table with the same name exists.
11. Click Verify to check whether the recovery task is configured correctly.
    • If the queue name is incorrect, the verification fails.
    • If the specified directory to be recovered does not exist, the verification fails.
    • If the forcibly replacement conditions are not met, the verification fails.

12. Click OK to save the settings.
13. In the recovery task list, locate a created task and click Start in the Operation column to execute the recovery task.
    • After the recovery is successful, the progress bar is in green.
    • After the recovery is successful, the recovery task cannot be executed again.
    • If the recovery task fails during the first execution, rectify the fault and click Retry to execute the task again.