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。
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