开启基于日志分片的备份

从 OceanBase 数据库 V2.2.77 版本开始，日志备份提供了基于 Piece 的按指定时间段切换目录的功能，即日志分片功能。开启日志分片功能后，管理员可以在备份备份时选择按照分片的日志备份来复制数据。

适用范围

对于 OceanBase 数据库 V2.2.77 版本，仅 OceanBase 数据库 V2.2.77 BP12（20220612090508） 及以上版本支持开启日志分片功能。

操作步骤

1. 使用 sys 租户的 root 用户登录数据库。

2. 通过指定 backup_dest_option 中的 log_archive_piece_switch_interval 参数值来开启日志分片的备份功能。

   示例如下：

   obclient> ALTER SYSTEM SET backup_dest_option='recovery_window=7d&auto_delete_obsolete_backup=true&log_archive_piece_switch_interval=1d';
   

   该示例中，日志备份会每天切分一个日志 Piece，保留 7 天。每天切分一个日志 Piece 表示从当前时间开始的 24 小时后，系统会自动开始切分下一个日志 Piece。受日志归档线程调度等其他因素的影响，下一次切分 Piece 的时间可能会有一定的延时。更多 backup_dest_option 配置项的说明信息请参见 backup_dest_option。

   开启日志分片的备份功能后，可以通过视图来查看日志备份的进度及日志分片的情况。

   • 查看日志进度

     obclient> SELECT * FROM CDB_OB_BACKUP_ARCHIVELOG;
     +-------------+-------------------+-----------+--------+----------------+-----------------+----------------------------+----------------------------+-------------+--------------+-------------------+---------------------+----------------------+
     | INCARNATION | LOG_ARCHIVE_ROUND | TENANT_ID | STATUS | START_PIECE_ID | BACKUP_PIECE_ID | MIN_FIRST_TIME             | MAX_NEXT_TIME              | INPUT_BYTES | OUTPUT_BYTES | COMPRESSION_RATIO | INPUT_BYTES_DISPLAY | OUTPUT_BYTES_DISPLAY |
     +-------------+-------------------+-----------+--------+----------------+-----------------+----------------------------+----------------------------+-------------+--------------+-------------------+---------------------+----------------------+
     |           1 |                 1 |         1 | DOING  |              1 |              12 | 2021-04-30 00:00:28.197301 | 2021-04-30 11:33:41.845543 |           0 |            0 |              NULL | 0.00MB              | 0.00MB               |
     |           1 |                 1 |      1001 | DOING  |              1 |              12 | 2021-04-30 00:00:28.197301 | 2021-04-30 11:33:58.444979 |           0 |            0 |              NULL | 0.00MB              | 0.00MB               |
     |           1 |                 1 |      1002 | DOING  |              1 |              12 | 2021-04-30 00:00:28.197301 | 2021-04-30 11:33:41.845543 |           0 |            0 |              NULL | 0.00MB              | 0.00MB               |
     +-------------+-------------------+-----------+--------+----------------+-----------------+----------------------------+----------------------------+-------------+--------------+-------------------+---------------------+----------------------+
     3 rows in set (0.07 sec)
     

   • 查看日志分片情况

     obclient> SELECT * FROM CDB_OB_BACKUP_PIECE_FILES ;
     +-------------+-----------+----------+-----------------+---------+-------------+----------------------------+----------------------------+----------------------------+--------+-------------+------------+----------------+
     | INCARNATION | TENANT_ID | ROUND_ID | BACKUP_PIECE_ID | COPY_ID | CREATE_DATE | START_TS                   | CHECKPOINT_TS              | MAX_TS                     | STATUS | FILE_STATUS | COMPATIBLE | START_PIECE_ID |
     +-------------+-----------+----------+-----------------+---------+-------------+----------------------------+----------------------------+----------------------------+--------+-------------+------------+----------------+
     |           1 |         1 |        1 |               1 |       0 |    20210430 | 2021-04-30 00:00:28.197301 | 2021-04-30 00:59:49.402568 | 2021-04-30 01:02:32.336195 | FROZEN | AVAILABLE   |          1 |              1 |
     |           1 |         1 |        1 |               2 |       0 |    20210430 | 2021-04-30 01:02:32.336195 | 2021-04-30 02:01:38.260158 | 2021-04-30 02:04:10.990039 | ACTIVE | AVAILABLE   |          1 |              1 |
     |           1 |      1001 |        1 |               1 |       0 |    20210430 | 2021-04-30 00:00:28.197301 | 2021-04-30 01:00:00.733364 | 2021-04-30 01:02:32.166782 | FROZEN | AVAILABLE   |          1 |              1 |
     |           1 |      1001 |        1 |               2 |       0 |    20210430 | 2021-04-30 01:02:32.166782 | 2021-04-30 02:01:38.260158 | 2021-04-30 02:04:09.731651 | ACTIVE | AVAILABLE   |          1 |              1 |
     +-------------+-----------+----------+-----------------+---------+-------------+----------------------------+----------------------------+----------------------------+--------+-------------+------------+----------------+