Backing Up HDFS NameNode Data

Scenario

To ensure NameNode service data security routinely or before a major operation on NameNode (such as upgrade or migration), you need to back up NameNode data. The backup data can be used to recover the system if an exception occurs or the operation has not achieved the expected result, minimizing the adverse impacts on services.

You can create a backup task on FusionInsight Manager to back up NameNode data. Both automatic and manual backup tasks are supported.

Prerequisites

• To back up data to a remote HDFS, the following conditions must be met:
  • A standby cluster for backing up data has been created. The authentication mode must be the same as that of the active cluster.
  • 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 backup type, period, policy, and other specifications have been planned based on the service requirements and you have checked whether Data storage path/LocalBackup/ has sufficient space on the active and standby management nodes.

• If you want to back up data to NAS, you have deployed the NAS server in advance.
• If you want to back up data to OBS, you have connected the current cluster to OBS and have the permission to access OBS.

Backing Up HDFS NameNode Data

1. On FusionInsight Manager, choose O&M > Backup and Restoration > Backup Management.
2. Click Create.
3. Set Name to the name of the backup task.
4. Select the cluster to be operated from Backup Object.
5. Set Mode to the type of the backup task.

   Periodic indicates that the backup task is executed by the system periodically. Manual indicates that the backup task is executed manually.

   Table 1 Periodic backup parameters

   Parameter	Description
   Started	Indicates the time when the task is started for the first time.
   Period	Indicates the task execution interval. The options include Hours and Days.
   Backup Policy	Only Full backup every time is supported. NOTE: Incremental backup is not supported when Manager data and component metadata are backed up. Only Full backup every time is supported. If Path Type is set to NFS or CIFS, incremental backup cannot be used. When incremental backup is used for NFS or CIFS backup, the latest full backup data is updated each time the incremental backup is performed. Therefore, no new recovery point is generated.

6. In Configuration, select NameNode.
7. Set Path Type of NameNode to a backup directory type.

   The following backup directory types are supported:

   • LocalDir: indicates that the backup files are stored on the local disk of the active management node and the standby management node automatically synchronizes the backup files. By default, the backup files are stored in Data storage path/LocalBackup/.
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
   • RemoteHDFS: indicates that the backup files are stored in the HDFS directory of the standby cluster. If you select this option, set the following parameters:
     • Destination NameService Name: indicates the NameService name of the standby 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: 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.
     • Target NameNode IP Address: indicates the service plane IP address of the NameNode in the standby cluster.
     • Target Path: indicates the path for storing backup files.
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
     • Queue Name: indicates the name of the Yarn queue used for backup task execution. The name must be the same as the name of the queue that is running properly in the cluster.
   • NFS: indicates that backup files are stored in the NAS using the NFS protocol. If you select this option, 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.
     • Server Shared Path: indicates the configured shared directory of the NAS server. (The shared path of the server cannot be set to the root directory, and the user group and owner group of the shared path must be nobody:nobody.)
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
   • CIFS: indicates that backup files are stored in the NAS using the CIFS protocol. If you select this option, 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.
     • Server Shared Path: indicates the configured shared directory of the NAS server. (The shared path of the server cannot be set to the root directory, and the user group and owner group of the shared path must be nobody:nobody.)
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
   • SFTP: indicates that backup files are stored in the server using the SFTP protocol.
     If you select this option, 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.
     • Server Shared Path: indicates the backup path on the SFTP server.
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
   • OBS: indicates that backup files are stored in OBS.

     If you select this option, set the following parameters:

     • Target Path: indicates the OBS directory for storing backup data.
     • Maximum Number of Backup Copies: indicates the number of backup file sets that can be retained in the backup directory.
     • NameService Name: indicates the NameService name of the backup directory. The default value is hacluster.
       

       Only MRS 3.1.0 or later supports data backup to OBS.

8. Click OK.
9. In the Operation column of the created task in the backup task list, click More and select Back Up Now to execute the backup task.

   After the backup task is executed, the system automatically creates a subdirectory for each backup task in the backup directory. The format of the subdirectory name is Backup task name_Task creation time, and the subdirectory is used to save data source backup files. The format of the backup file name is Version_Data source_Task execution time.tar.gz.