KingbaseES V8R6 集群环境wal日志清理

案例说明：

1、对于集群中的wal日志，除了需要在备库执行recovery外，在集群主备切换（switchover或failover）时，sys_rewind都要读取wal日志，将数据库恢复到一致性状态。

2、对于集群主备库中的wal日志，在清理时，经过测试，理论上在checkpoint所在的wal日志之前的都可以清理，但这是比较理想的状态，在生产环境中，建议保留3天到一个星期的wal日志，避免因为主备延迟，导致在集群切换时，因为缺少wal日志失败。

3、对于KingbaseES V8R6的集群，如果在主备库上通过sys_backup.sh工具建立了备份，归档日志会自动备份，应该也会随着历史备份的清理，自动被清理。如果节点没有建立sys_backup.sh的备份，可以通过 sys_archivecleanup工具清理，原则也是在生产环境中，建议保留3天到一个星期的归档日志。

数据库版本：

test=# select version;
                                                       version
------------------------------------------------------------------------------------------------------------------

 KingbaseES V008R006C005B0023 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit
(1 row)

集群节点信息：

[kingbase@node1 bin]$ cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

192.168.8.200   node1   #集群节点node200
192.168.8.201   node2   #集群节点node201

 ID | Name    | Role    | Status    | Upstream | repmgrd | PID   | Paused? | Upstream last seen
----+---------+---------+-----------+----------+---------+-------+---------+--------------------
 1  | node200 | primary | * running |          | running | 29303 | no      | n/a
 2  | node201 | standby |   running | node200  | running | 29748 | no      | 1 second(s) ago

一、集群switchover切换测试

1、查看主备库控制文件信息

1）主库控制文件

[kingbase@node1 bin]$ ./sys_controldata -D ../data
sys_control version number:            1201
Catalog version number:               202110271
Database system identifier:           7094057752387829054
Database cluster state:               in production
sys_control last modified:             Tue 10 May 2022 12:33:09 PM CST
Latest checkpoint location:           1/29001768
Latest checkpoint's REDO location:    1/29001738
Latest checkpoint's REDO WAL file:    000000030000000100000029
Latest checkpoint's TimeLineID:       3

2）备库控制文件

[kingbase@node2 bin]$ ./sys_controldata -D ../data
sys_control version number:            1201
Catalog version number:               202110271
Database system identifier:           7094057752387829054
Database cluster state:               in archive recovery
sys_control last modified:             Thu 19 May 2022 12:05:06 PM CST
Latest checkpoint location:           1/29001768
Latest checkpoint's REDO location:    1/29001738
Latest checkpoint's REDO WAL file:    000000030000000100000029
Latest checkpoint's TimeLineID:       3

2、清理wal日志（将主备库日志都只保留checkpoint所在的wal日志文件（包括）及以后的）

# 主库保留wal日志

[kingbase@node1 sys_wal]$ ls -lh
total 49M

-rw-------. 1 kingbase kingbase  16M May 10 13:19 000000030000000100000029
-rw-------. 1 kingbase kingbase  16M May 10 13:19 00000003000000010000002A
-rw-------. 1 kingbase kingbase  16M May 10 13:23 00000003000000010000002B
-rw-------. 1 kingbase kingbase   85 May 18 11:28 00000003.history
drwx------. 2 kingbase kingbase  24K May 10 13:19 archive_status
drwxrwxr-x. 2 kingbase kingbase 4.0K May 19 12:58 log_bk

# 备库保留wal日志
[kingbase@node2 sys_wal]$ ls -lh
total 49M
-rw------- 1 kingbase kingbase  16M May 19 12:51 000000030000000100000029
-rw------- 1 kingbase kingbase  16M May 19 12:51 00000003000000010000002A
-rw------- 1 kingbase kingbase  16M May 19 12:55 00000003000000010000002B
-rw------- 1 kingbase kingbase   85 May 18 11:28 00000003.history
drwx------ 2 kingbase kingbase  12K May 19 12:51 archive_status
drwxrwxr-x 2 kingbase kingbase 4.0K May 19 13:00 log_bk

3、执行repmgr standby switchover

1）查看当前集群状态信息

[kingbase@node2 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
 1  | node200 | primary | * running |          | default  | 100      | 3        | host=192.168.8.200 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node201 | standby |   running | node200  | default  | 100      | 3        | host=192.168.8.201 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

2）执行switchover

[kingbase@node2 bin]$ ./repmgr standby switchover -h 192.168.8.200 -U esrep -d esrep
WARNING: following problems with command line parameters detected:
......
INFO: unpause node "node201" (ID 2) successfully
NOTICE: STANDBY SWITCHOVER has completed successfully

[kingbase@node2 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
 1  | node200 | standby |   running | node201  | default  | 100      | 3        | host=192.168.8.200 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node201 | primary | * running |          | default  | 100      | 4        | host=192.168.8.201 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

执行回切测试：
 [kingbase@node1 bin]$ ./repmgr standby switchover -h 192.168.8.201 -U esrep -d esrep
WARNING: following problems with command line parameters detected:

INFO: unpause node "node201" (ID 2) successfully
NOTICE: STANDBY SWITCHOVER has completed successfully

[kingbase@node1 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
 1  | node200 | primary | * running |          | default  | 100      | 5        | host=192.168.8.200 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node201 | standby |   running | node200  | default  | 100      | 4        | host=192.168.8.201 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

=== 如上所示，switchover切换成功！====

二、集群 failover 切换测试

1、查看当前集群状态信息

[kingbase@node2 bin]$ ./repmgr cluster show
ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
1  | node200 | standby |   running | node201  | default  | 100      | 5        | host=192.168.8.200 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2  | node201 | primary | * running |          | default  | 100      | 6        | host=192.168.8.201 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

2、查看主备库控制文件信息

# 主库：
[kingbase@node2 bin]$ ./sys_controldata -D ../data
sys_control version number:            1201
Catalog version number:               202110271
Database system identifier:           7094057752387829054
Database cluster state:               in production
sys_control last modified:             Thu 19 May 2022 01:26:08 PM CST
Latest checkpoint location:           1/409BA150
Latest checkpoint's REDO location:    1/3EADD130
Latest checkpoint's REDO WAL file:    00000006000000010000003E

# 备库：
[kingbase@node1 bin]$ ./sys_controldata -D ../data
sys_control version number:            1201
Catalog version number:               202110271
Database system identifier:           7094057752387829054
Database cluster state:               in archive recovery
sys_control last modified:             Thu 19 May 2022 01:22:19 PM CST
Latest checkpoint location:           1/37000028
Latest checkpoint's REDO location:    1/37000028
Latest checkpoint's REDO WAL file:    000000050000000100000037

3、清理主备库wal日志（将主备库日志都只保留checkpoint所在的wal日志文件（包括）及以后的）

# 主库保留wal日志
[kingbase@node2 sys_wal]$ ls -lh
total 65M
-rw------- 1 kingbase kingbase  16M May 19 13:25 00000006000000010000003E
-rw------- 1 kingbase kingbase  16M May 19 13:26 00000006000000010000003F
-rw------- 1 kingbase kingbase  16M May 19 13:26 000000060000000100000040
-rw------- 1 kingbase kingbase  16M May 19 13:26 000000060000000100000041
-rw------- 1 kingbase kingbase  214 May 19 13:18 00000006.history
drwx------ 2 kingbase kingbase  16K May 19 13:26 archive_status
drwxrwxr-x 2 kingbase kingbase 4.0K May 19 13:30 log_bk

# 备库保留wal日志
[kingbase@node1 sys_wal]$ ls -lh
total 193M
-rw-------. 1 kingbase kingbase  16M May 19 13:17 000000050000000100000037
-rw-------. 1 kingbase kingbase  171 May 19 13:03 00000005.history
-rw-------. 1 kingbase kingbase  16M May 19 13:23 000000060000000100000037
-rw-------. 1 kingbase kingbase  16M May 19 13:24 000000060000000100000038
-rw-------. 1 kingbase kingbase  16M May 19 13:24 000000060000000100000039
-rw-------. 1 kingbase kingbase  16M May 19 13:24 00000006000000010000003A
-rw-------. 1 kingbase kingbase  16M May 19 13:24 00000006000000010000003B
-rw-------. 1 kingbase kingbase  16M May 19 13:25 00000006000000010000003C
-rw-------. 1 kingbase kingbase  16M May 19 13:25 00000006000000010000003D
-rw-------. 1 kingbase kingbase  16M May 19 13:25 00000006000000010000003E
-rw-------. 1 kingbase kingbase  16M May 19 13:25 00000006000000010000003F
-rw-------. 1 kingbase kingbase  16M May 19 13:26 000000060000000100000040
-rw-------. 1 kingbase kingbase  16M May 19 13:26 000000060000000100000041
-rw-------. 1 kingbase kingbase  214 May 19 13:21 00000006.history
drwx------. 2 kingbase kingbase  24K May 19 13:26 archive_status
drwxrwxr-x. 2 kingbase kingbase 4.0K May 19 13:28 log_bk

4、执行failover切换测试

1）关闭主库数据库服务

[kingbase@node2 bin]$ ./sys_ctl stop -D ../data
waiting for server to shut down....... done
server stopped

2）查看切换结果

[kingbase@node1 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+---------------------------------------------------------------------------------------------------------------------------------------------------
 1  | node200 | primary | * running |          | default  | 100      | 7        | host=192.168.8.200 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node201 | standby |   running |          | default  | 100      | 6        | host=192.168.8.201 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

=== 如上所示，failover切换成功！====

三、总结

手工清理wal日志，请参考《KingbaseES 单实例环境wal(xlog)日志清理案例》

https://www.cnblogs.com/kingbase/p/16263467.html