View parameters related to data backup

After a backup operation is performed, you can view the parameters related to backup by checking the settings of the relevant parameters.

Procedure

1. Log in to the sys tenant of the cluster as the root user.

2. Execute the following statements to query parameters related to backup:

   • Query the current number of worker threads for high availability tasks with low priority, such as backup and backup cleanup.

     Here is the sample code:

     obclient [(none)]> SHOW PARAMETERS LIKE '%ha_low_thread_score%'\G
     

     Here is the sample result:

     *************************** 1. row ***************************
              zone: zone1
          svr_type: observer
            svr_ip: 172.xx.xxx.xxx
          svr_port: 2882
              name: ha_low_thread_score
         data_type: INT
             value: 0
              info: the current work thread score of high availability low thread. Range: [0,100] in integer. Especially, 0 means default value
           section: OBSERVER
             scope: TENANT
            source: DEFAULT
        edit_level: DYNAMIC_EFFECTIVE
     default_value: 0
         isdefault: 1
     1 row in set
     

     The tenant-level parameter ha_low_thread_score specifies the current number of worker threads for high availability tasks with low priority, such as backup and backup cleanup. The default value is 0. If you find that the data backup task is running too slowly, you can appropriately increase the value of the ha_low_thread_score parameter. We recommend that you double the value each time. For more information about the ha_low_thread_score parameter, see ha_low_thread_score.

     Here is the sample code for setting the number of concurrent writes to the file system when performing a backup:

     obclient [(none)]>  ALTER SYSTEM SET ha_low_thread_score = 4 TENANT = mysql_tenant;
     

     In this example, the value of the ha_low_thread_score parameter is set to 4, which specifies the number of worker threads for backup tasks in the mysql_tenant tenant.

   • Query the backup parameters of a tenant.

     The sys tenant can query the backup parameters configured for each tenant in the current cluster by using the oceanbase.CDB_OB_BACKUP_PARAMETER view. A user tenant can query the backup parameters configured for the tenant by using the oceanbase.DBA_OB_BACKUP_PARAMETER view in MySQL mode or the SYS.DBA_OB_BACKUP_PARAMETER view in Oracle mode.

     obclient [(none)]> SELECT * FROM oceanbase.CDB_OB_BACKUP_PARAMETER\G
     

     Here is the sample result:

     *************************** 1. row ***************************
     TENANT_ID: 1004
          NAME: data_backup_dest
         VALUE: oss://oceanbase-test-bucket/backup/data/?host=xxx.aliyun-inc.com&access_id=xxx&access_key=xxx&delete_mode=delete&checksum_type=md5&enable_worm=true
     1 row in set
     

     In this example, the data backup path (data_backup_dest) for the tenant with TENANT_ID of 1004 is oss://oceanbase-test-bucket/backup/?host=xxx.aliyun-inc.com&access_id=xxx&access_key=xxx, and its backup file cleanup mode (delete_mode) is delete. The delete_mode parameter can take the following two values:

     • delete: Directly delete the eligible backup files when performing backup file cleanup.

       In this mode, when you clean up backup files, the system directly deletes the files that meet the cleanup criteria.

     • tagging: Set a tag for the eligible backup files when performing backup file cleanup. The files will still be retained.

       In this mode, the system tags the backup files that meet the specified requirements during backup file cleanup. The tag key is delete_mode, and the tag value is tagging. You can manage these backup files on Alibaba Cloud Object Storage Service (OSS), Tencent Cloud Object Storage (COS), or Amazon Simple Storage Service (S3) over their lifecycle by tag.

     Additionally, in the parameters of the backup path for the tenant, checksum_type=md5 indicates that the MD5 algorithm is used to verify the integrity of backup files, and enable_worm=true specifies that OceanBase Database performs write and delete operations on the path according to the WORM policy.

   • View information related to the backup path of a tenant.

     The CDB_OB_BACKUP_STORAGE_INFO view records information about the backup or archive paths for all tenants.

     obclient [oceanbase]> SELECT PATH, DEST_TYPE, EXTENSION FROM oceanbase.CDB_OB_BACKUP_STORAGE_INFO WHERE DEST_TYPE='backup_data';
     

     An example of the query result is as follows:

     +-----------+---------------------------------------------+-------------+------------------------------------+
     | TENANT_ID | PATH                                        | DEST_TYPE   | EXTENSION                          | 
     +-----------+---------------------------------------------+-------------+------------------------------------+
     |      1004 | oss://oceanbase-test-bucket/backup/data     | backup_data | checksum_type=md5&enable_worm=true |
     +-----------+---------------------------------------------+-------------+------------------------------------+
     1 row in set
     

     In the query result, for the tenant with ID 1004, the backup path is oss://oceanbase-test-bucket/backup/data. The checksum_type=md5 indicates that the MD5 algorithm is used to verify the integrity of backup files, and enable_worm=true specifies that OceanBase Database performs write and delete operations on the path according to the WORM policy.