KingbaseES R6 集群repmgr.conf参数'recovery'测试案例(三)

案例三：测试‘recovery = manual’

1、查看集群节点状态信息：

[kingbase@node1 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+---------------------------
 1  | node243 | primary | * running |          | default  | 100      | 3        | host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node248 | standby |   running | node243  | default  | 100      | 3        | host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

2、查看recovery配置信息

3、重启主库主机系统

[root@node3 ~]# reboot

4、查看备库hamgr日志

=从以下日志信息获知，主库系统宕机后，集群执行主备切换，备库被提升为主库。==

[2022-03-02 10:32:38] [NOTICE] starting monitoring of node "node248" (ID: 2)
[2022-03-02 10:32:38] [INFO] "connection_check_type" set to "ping"
[2022-03-02 10:32:38] [INFO] monitoring connection to upstream node "node243" (ID: 1)
[2022-03-02 10:32:38] [NOTICE] try to change wal catched_up state to 1
[2022-03-02 10:32:38] [INFO] primary flush lsn is 0/1F000D40, local flush lsn is 0/1F000D40
[2022-03-02 10:32:38] [NOTICE] try to change streaming_sync state to TRUE
[2022-03-02 10:34:24] [WARNING] unable to ping "host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3"
[2022-03-02 10:34:24] [DETAIL] PQping() returned "PQPING_REJECT"
[2022-03-02 10:34:24] [WARNING] unable to connect to upstream node "node243" (ID: 1)
[2022-03-02 10:34:24] [INFO] sleeping 6 seconds until next reconnection attempt
[2022-03-02 10:34:30] [INFO] checking state of node 1, 1 of 10 attempts
[2022-03-02 10:34:40] [WARNING] unable to ping "user=esrep connect_timeout=10 dbname=esrep host=192.168.7.243 port=54321 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3 fallback_application_name=repmgr"
[2022-03-02 10:34:40] [DETAIL] PQping() returned "PQPING_NO_RESPONSE"
[2022-03-02 10:34:40] [INFO] sleeping 6 seconds until next reconnection attempt

......

[2022-03-02 10:35:47] [INFO] checking state of node 1, 10 of 10 attempts
[2022-03-02 10:35:47] [WARNING] unable to ping "user=esrep connect_timeout=10 dbname=esrep host=192.168.7.243 port=54321 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3 fallback_application_name=repmgr"
[2022-03-02 10:35:47] [DETAIL] PQping() returned "PQPING_NO_RESPONSE"
[2022-03-02 10:35:47] [WARNING] unable to reconnect to node 1 after 10 attempts
[2022-03-02 10:35:47] [NOTICE] setting "wal_retrieve_retry_interval" to 86405000 milliseconds
[2022-03-02 10:35:47] [WARNING] wal receiver not running
[2022-03-02 10:35:47] [NOTICE] WAL receiver disconnected on all sibling nodes
[2022-03-02 10:35:47] [INFO] WAL receiver disconnected on all 0 sibling nodes
[2022-03-02 10:35:47] [INFO] 0 active sibling nodes registered
[2022-03-02 10:35:47] [INFO] primary and this node have the same location ("default")
[2022-03-02 10:35:47] [INFO] no other sibling nodes - we win by default
[2022-03-02 10:35:47] [NOTICE] setting "wal_retrieve_retry_interval" to 5000 ms
[2022-03-02 10:35:48] [NOTICE] this node is the only available candidate and will now promote itself
[2022-03-02 10:35:48] [INFO] try to ping the trusted_servers "192.168.7.1" before execute promote_command
[2022-03-02 10:35:50] [NOTICE] PING 192.168.7.1 (192.168.7.1) 56(84) bytes of data.

--- 192.168.7.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1008ms
rtt min/avg/max/mdev = 2.473/2.535/2.598/0.080 ms

[2022-03-02 10:35:50] [NOTICE] successfully ping one or more of the trusted_servers "192.168.7.1"
[2022-03-02 10:35:51] [NOTICE] PING 192.168.7.241 (192.168.7.241) 56(84) bytes of data.

--- 192.168.7.241 ping statistics ---
2 packets transmitted, 0 received, +1 errors, 100% packet loss, time 1000ms

[2022-03-02 10:35:51] [WARNING] ping host"192.168.7.241" failed
[2022-03-02 10:35:51] [DETAIL] average RTT value is not greater than zero
[2022-03-02 10:35:51] [INFO] loadvip result: 1, arping result: 1
[2022-03-02 10:35:51] [NOTICE] new primary node (ID: 2) acquire the virtual ip 192.168.7.241/24 success
[2022-03-02 10:35:51] [INFO] promote_command is:
  "/home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/repmgr  standby promote -f /home/kingbase/cluster/R6C5/R6C5R/kingbase/etc/repmgr.conf"
NOTICE: promoting standby to primary
DETAIL: promoting server "node248" (ID: 2) using sys_promote()
NOTICE: waiting up to 60 seconds (parameter "promote_check_timeout") for promotion to complete
[2022-03-02 10:35:51] [NOTICE] try to stop old primary db (host: "192.168.7.243")
INFO: SET synchronous TO "async" on primary host
NOTICE: STANDBY PROMOTE successful
DETAIL: server "node248" (ID: 2) was successfully promoted to primary
[2022-03-02 10:35:56] [INFO] 0 followers to notify
[2022-03-02 10:35:56] [INFO] switching to primary monitoring mode
[2022-03-02 10:35:56] [NOTICE] monitoring cluster primary "node248" (ID: 2)
[2022-03-02 10:35:56] [INFO] create a thread 0x7fdeaa4b9700 to check the cluster status
[2022-03-02 10:35:57] [INFO] node (ID: 1): no server running
[2022-03-02 10:35:57] [INFO] [thread 0x7fdeaa4b9700] the cluster has no other running primary node, exit

5、原主库系统正常启动

1）从新主库查看集群状态 信息

=从以下信息可以获知，集群现在处于‘双主’状态，只是原主库是‘failed’，无法连接。=

[kingbase@node1 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
 1  | node243 | primary | - failed  |          | default  | 100      | ?        | host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node248 | primary | * running |          | default  | 100      | 10       | host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

WARNING: following issues were detected
  - unable to connect to node "node243" (ID: 1)
You have new mail in /var/spool/mail/kingbase

2）在新主库（原备库）创建复制槽

# 创建replication slots

test=# select sys_create_physical_replication_slot('repmgr_slot_1');
 sys_create_physical_replication_slot
--------------------------------------
 (repmgr_slot_1,)
(1 row)

test=# select sys_create_physical_replication_slot('repmgr_slot_2');
 sys_create_physical_replication_slot
--------------------------------------
 (repmgr_slot_2,)
(1 row)

test=# select * from sys_replication_slots;
   slot_name   | plugin | slot_type | datoid | database | temporary | active | active_pid | xmin | catalog_xmin |
restart_lsn | confirmed_flush_lsn
---------------+--------+-----------+--------+----------+-----------+--------+------------+-----
 repmgr_slot_1 |        | physical  |        |          | f         | f      |            |      |              |
            |
 repmgr_slot_2 |        | physical  |        |          | f         | f      |            |      |              |
            |
(2 rows)

3）在原主库（新主库）执行以下恢复操作

# 备份data目录
[kingbase@node3 kingbase]$ cp data data.bk -r

# 生成备库标识文件
[kingbase@node3 kingbase]$ cd data
[kingbase@node3 data]$ touch standby.signal

4）在原主库执行repmgr node rejoin重新加入到集群

 [kingbase@node3 bin]$ ./repmgr node rejoin -h 192.168.7.248 -U esrep -d esrep --force-rewind
NOTICE: sys_rewind execution required for this node to attach to rejoin target node 2
DETAIL: rejoin target server's timeline 10 forked off current database system timeline 9 before current recovery point 0/200000A0
NOTICE: executing sys_rewind
DETAIL: sys_rewind command is "/home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/sys_rewind -D '/home/kingbase/cluster/R6C5/R6C5R/kingbase/data' --source-server='host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3'"
sys_rewind: servers diverged at WAL location 0/1F000D70 on timeline 9
sys_rewind: rewinding from last common checkpoint at 0/1E000A70 on timeline 9
sys_rewind: find last common checkpoint start time from 2022-03-02 10:52:34.133058 CST to 2022-03-02 10:52:34.358066 CST, in "0.225008" seconds.
sys_rewind: update the control file: minRecoveryPoint is '0/1F011AD0', minRecoveryPointTLI is '10', and database state is 'in archive recovery'
sys_rewind: rewind start wal location 0/1E000A40 (file 00000009000000000000001E), end wal location 0/1F011AD0 (file 0000000A000000000000001F). time from 2022-03-02 10:52:34.133058 CST to 2022-03-02 10:53:06.442270 CST, in "32.309212" seconds.
sys_rewind: Done!
NOTICE: 0 files copied to /home/kingbase/cluster/R6C5/R6C5R/kingbase/data
NOTICE: setting node 1's upstream to node 2
WARNING: unable to ping "host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3"
DETAIL: PQping() returned "PQPING_NO_RESPONSE"
NOTICE: begin to start server at 2022-03-02 10:53:06.588331
NOTICE: starting server using "/home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/sys_ctl  -w -t 90 -D '/home/kingbase/cluster/R6C5/R6C5R/kingbase/data' -l /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/logfile start"
NOTICE: start server finish at 2022-03-02 10:53:07.313294
NOTICE: NODE REJOIN successful
DETAIL: node 1 is now attached to node 2

5）启动新备库数据库服务

[kingbase@node3 bin]$ ps -ef |grep kingbase
kingbase  3218     1  0 10:36 ?        00:00:00 /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/kbha -A daemon -f /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/../etc/repmgr.conf
kingbase  5817     1  0 10:49 ?        00:00:01 /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/repmgrd -d -v -f /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/../etc/repmgr.conf
kingbase  6730     1  0 10:53 ?        00:00:00 /home/kingbase/cluster/R6C5/R6C5R/kingbase/bin/kingbase -D /home/kingbase/cluster/R6C5/R6C5R/kingbase/data
kingbase  6731  6730  0 10:53 ?        00:00:00 kingbase: logger
kingbase  6732  6730  0 10:53 ?        00:00:00 kingbase: startup   recovering 0000000A000000000000001F
kingbase  6736  6730  0 10:53 ?        00:00:00 kingbase: checkpointer
kingbase  6737  6730  0 10:53 ?        00:00:00 kingbase: background writer
kingbase  6738  6730  0 10:53 ?        00:00:00 kingbase: stats collector
kingbase  6739  6730  0 10:53 ?        00:00:00 kingbase: walreceiver   streaming 0/1F012A78
kingbase  6743  6730  0 10:53 ?        00:00:00 kingbase: esrep esrep 192.168.7.243(55941) idle
kingbase  6750  6730  0 10:53 ?        00:00:00 kingbase: esrep esrep 192.168.7.243(55947) idle

6）查看集群节点状态

[kingbase@node3 bin]$ ./repmgr cluster show
 ID | Name    | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------
 1  | node243 | standby |   running | node248  | default  | 100      | 9        | host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node248 | primary | * running |          | default  | 100      | 10       | host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3

7）重启集群测试（可选）

[kingbase@node3 bin]$ ./sys_monitor.sh restart
2022-03-02 10:55:26 Ready to stop all DB ...
....
server started
2022-03-02 10:55:52 execute to start DB on "[192.168.7.248]" success, connect to check it.
2022-03-02 10:55:53 DB on "[192.168.7.248]" start success.
 ID | Name    | Role    | Status    | Upstream  | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+-----------+----------+----------+----------+---------------
 1  | node243 | standby |   running | ! node248 | default  | 100      | 10       | host=192.168.7.243 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
 2  | node248 | primary | * running |           | default  | 100      | 10       | host=192.168.7.248 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
WARNING: following issues were detected
  - node "node243" (ID: 1) is not attached to its upstream node "node248" (ID: 2)
2022-03-02 10:55:53 The primary DB is started.
......
2022-03-02 10:56:15 repmgrd on "[192.168.7.248]" start success.
 ID | Name    | Role    | Status    | Upstream | repmgrd | PID   | Paused? | Upstream last seen
----+---------+---------+-----------+----------+---------+-------+---------+--------------------
 1  | node243 | standby |   running | node248  | running | 9500  | no      | 1 second(s) ago
 2  | node248 | primary | * running |          | running | 27881 | no      | n/a
[2022-03-02 10:56:18] [NOTICE] redirecting logging output to "/home/kingbase/cluster/R6C5/R6C5R/kingbase/log/kbha.log"
[2022-03-02 10:56:20] [NOTICE] redirecting logging output to "/home/kingbase/cluster/R6C5/R6C5R/kingbase/log/kbha.log"
2022-03-02 10:56:22 Done.

=从以上信息获知，通过手工执行repmgr node rejoin，原主库作为新备库重新加入到集群中。=

总结：

   1、对于recovery=standby，主库节点系统宕机后，集群执行主库切换，原主库需要人工配置为备库模式，并启动数据库服务，然后集群可自动将其加入到集群。
   2、对于recovery=automatic，主库节点系统宕机后，集群执行主库切换，不需要人工参与，原主库将作为新的备库自动加入到集群。
   3、对于recovery=manual，主库节点系统宕机后，集群执行主库切换，需要人工参与，在原主库执行‘repmgr node rejoin’操作，将原主库将作为新的备库自动加入到集群。
   4、对于无DBA日常监控管理的生产环境，可以考虑将recovery配置为automatic，提升集群架构的可靠性。