KingbaseES V8R6备份恢复案例之---sys_waldump解析wal日志PITR恢复

news2024/11/25 18:27:42

案例说明：
复现用户删除表(drop table)误操作，通过wal日志解析找到误操作时间点，执行基于时间点的恢复(PITR)。适用版本： KingbaseES V8R6

一、模拟业务现场操作

1、查看当前对象信息

prod=# \d
               List of relations
 Schema |        Name         | Type  | Owner
--------+---------------------+-------+--------
 public | dual                | view  | system
 public | sys_stat_statements | view  | system
 public | t_centerprises      | table | system
 public | t1                  | table | system
 public | TB1                 | table | system
 public | tb2                 | table | system
 public | tbl_test            | table | system
(7 rows)

2、执行事务操作

prod=# select count(*) from t1;
 count
-------
 10000
(1 row)

prod=# insert into t1 values(generate_series(1001,2000),'usr'||generate_series(1001,2000));
INSERT 0 1000
prod=# select count(*) from t1;
 count
-------
 11000
(1 row)

# 当前wal对应lsn
prod=# select sys_current_wal_lsn();
 sys_current_wal_lsn
---------------------
 0/3D000058
(1 row)

prod=# insert into t1 values(generate_series(11001,20000),'usr'||generate_series(11001,20000));
INSERT 0 9000

prod=# select count(*) from t1;
 count
-------
 20000
(1 row)

# 查看数据库当前wal日志文件
prod=# select pg_current_wal_lsn(),pg_walfile_name(pg_current_wal_lsn()),pg_walfile_name_offset(pg_current_wal_lsn());
 pg_current_wal_lsn |     pg_walfile_name      |      pg_walfile_name_offset
--------------------+--------------------------+-----------------------------------
 0/3D0A5090         | 00000001000000000000003D | (00000001000000000000003D,675984)
(1 row)

# 用户误删除表
prod=# drop table t1;
DROP TABLE

二、查看当前数据库的物理备份

如下图所示：以下是用户误操作时间点之前的物理备份。

三、sys_waldump解析wal日志(查看误操作准确时间点)Tips：
对于用户的误操作，要执行PITR的恢复，需要找到误操作的准确时间点，在生产环境中，可以根据误操作大概的时间点，对时间点前后的归档及在线日志进行解析，本案例为了简化操作，只解析了一个wal日志。[kingbase@node102 sys_wal]$ /opt/Kingbase/ES/V8R6_C6/Server/bin/sys_waldump 00000001000000000000003D -s '0/3D000058'

1、Insert操作日志解析

prod=#  select oid,relname from sys_class where oid=16500;
  oid  | relname
-------+---------
 16500 | t1
(1 row)

2、更新pg_statistic系统表日志

prod=#  select oid,relname from sys_class where oid=2696 or oid=2619;
 oid  |             relname
------+----------------------------------
 2619 | pg_statistic
 2696 | pg_statistic_relid_att_inh_index
(2 rows)

3、drop table日志解析

# drop table 将清理系统表中对象的信息
prod=#  select oid,relname from sys_class where oid=2608;
 oid  |  relname
------+-----------
 2608 | pg_depend
(1 row)

=如上图所示，从wal日志中可以解析到‘drop table’事务commit的时间点，“COMMIT 2022-09-27 11:09:45.005736 CST”，可以以此时间点作为PITR恢复的时间点，来恢复用户误删除的表。=

四、执行基于时间点(PITR)恢复

Tips：
对于生产环境可以异地恢复，在另外的实例执行PITR的恢复，将恢复出的数据，再导入到生产实例中。本案例是从本实例恢复，需要将数据库服务关闭。

1、关闭数据库服务并备份数据库文件

[kingbase@node102 bin]$ ./sys_ctl stop -D /data/kingbase/v8r6_c6/data
[kingbase@node102 v8r6_c6]$ mv data data.bk

2、执行PIRT恢复

[kingbase@node102 bin]$ /opt/Kingbase/ES/V8R6_C6/Server/bin/sys_rman --config=/home/kingbase/kbbr7_repo/sys_rman.conf --stanza=king  --type=time --target='2022-09-27 11:09:45'  restore

.......
2022-09-27 13:34:05.234 P00   INFO: Restore Process: FILE: 2605 / 2605 100%       SZIE: 105160230 bytes / 105160230 bytes 100.3MB / 100.3MB 100%
2022-09-27 13:34:05.239 P00   INFO: write updated /data/kingbase/v8r6_c6/data/kingbase.auto.conf
2022-09-27 13:34:05.244 P00   INFO: restore global/sys_control (performed last to ensure aborted restores cannot be started)
2022-09-27 13:34:05.245 P00   INFO: restore size = 100.3MB, file total = 2605
2022-09-27 13:34:05.246 P00   INFO: restore command end: completed successfully (2308ms)

3、查看恢复后的数据1)查看kingbase.auto.conf配置

[kingbase@node102 data]$ cat kingbase.auto.conf
# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command.

# Recovery settings generated by sys_rman restore on 2022-09-27 13:39:58
restore_command = '/opt/Kingbase/ES/V8R6_C6/KESRealPro/V008R006C006B0013/Server/bin/sys_rman --config=/home/kingbase/kbbr7_repo/sys_rman.conf --stanza=king archive-get %f "%p"'
recovery_target_time = '2022-09-27 11:09:45'

2)启动数据库服务[kingbase@node102 bin]$ ./sys_ctl start -D /data/kingbase/v8r6_c6/data

3)查看sys_log日志