案例环境：
操作系统：
[root@node1 ~]# cat /etc/centos-release
CentOS Linux release 7.2.1511 (Core)
数据库：
test=# select version();
version
------------------------------------------------------------------------------
KingbaseES V008R006C003B0010 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit
(1 row)
集群架构：
一、查看当前集群节点状态信息
1、集群节点信息
[kingbase@node3 bin]$ ./repmgr cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----
1 | node248 | primary | * running | | default | 100 | 5 | 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 | node249 | standby | running | node248 | default | 100 | 5 | host=192.168.7.249 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
3 | node243 | standby | running | node248 | default | 100 | 5 | 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、主备流复制信息
test=# select * from sys_stat_replication;
pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | backend_xmin | sta
te | sent_lsn | write_lsn | flush_lsn | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync_state | reply_time
------+----------+---------+------------------+---------------+-----------
3403 | 16384 | esrep | node249 | 192.168.7.249 | | 14247 | 2021-03-01 12:03:37.651419+08 | | strea
ming | 1/F9005BA0 | 1/F9005BA0 | 1/F9005BA0 | 1/F9005BA0 | | | | 1 | quorum | 2021-03-01 12:31:56.432
910+08
3419 | 16384 | esrep | node243 | 192.168.7.243 | | 34939 | 2021-03-01 12:03:43.876552+08 | | strea
ming | 1/F9005BA0 | 1/F9005BA0 | 1/F9005BA0 | 1/F9005BA0 | | | | 1 | quorum | 2021-03-01 12:30:42.663
663+08
(2 rows)
3、复制槽信息
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_2 | | physical | | | f | t | 3403 | | | 1/F9005BA0 |
repmgr_slot_3 | | physical | | | f | t | 3419 | | | 1/F9005BA0 |
(2 rows)
二、将standby节点unregister
1、unregister standby node
[kingbase@node3 bin]$ ./repmgr standby unregister;
INFO: connecting to local standby
INFO: connecting to primary database
NOTICE: unregistering node 3
INFO: try to drop slot "repmgr_slot_3" of node 3 on primary node
WARNING: replication slot "repmgr_slot_3" is still active on node 3
INFO: standby unregistration complete
2、查看集群节点信息
[kingbase@node3 bin]$ ./repmgr cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----
1 | node248 | primary | * running | | default | 100 | 5 | 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 | node249 | standby | running | node248 | default | 100 | 5 | host=192.168.7.249 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
3、查看流复制信息
test=# select * from sys_stat_replication;
pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | backend_xmin | sta
te | sent_lsn | write_lsn | flush_lsn | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync_state | reply_time
------+----------+---------+------------------+---------------+-----------------+-------------+-------------------------------+--------------+------
3403 | 16384 | esrep | node249 | 192.168.7.249 | | 14247 | 2021-03-01 12:03:37.651419+08 | | strea
ming | 1/F9007590 | 1/F9007590 | 1/F9007590 | 1/F9007590 | | | | 1 | quorum | 2021-03-01 12:35:38.819
940+08
(1 row)
=== 从以上获知，集群节点信息已经没有unregister的节点信息和流复制信息===
三、停止本地集群服务删除复制槽
1、停止本地集群服务
[kingbase@node3 bin]$ ./sys_monitor.sh stoplocal
Service process "node_export" was killed at process 4928
Service process "postgres_ex" was killed at process 4929
2021-03-01 12:33:52 begin to stop repmgrd on "[localhost]".
2021-03-01 12:33:54 repmgrd on "[localhost]" stop success.
2021-03-01 12:33:54 begin to stop DB on "[localhost]".
waiting for server to shut down.... done
server stopped
2021-03-01 12:33:55 DB on "[localhost]" stop success.
2、查看复制槽信息
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_2 | | physical | | | f | t | 3403 | | | 1/F9007590 |
repmgr_slot_3 | | physical | | | f | f | | | | 1/F9007590 |
(2 rows)
3、删除复制槽
test=# select sys_drop_replication_slot(‘repmgr_slot_3‘);
sys_drop_replication_slot
---------------------------
(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_2 | | physical | | | f | t | 3403 | | | 1/F9007590 |
(1 row)
四、重新启动集群服务测试
[kingbase@node1 bin]$ ./sys_monitor.sh restart
2021-03-01 12:37:43 Ready to stop all DB ...
Service process "node_export" was killed at process 4546
Service process "postgres_ex" was killed at process 4547
Service process "node_export" was killed at process 4242
Service process "postgres_ex" was killed at process 4243
2021-03-01 12:37:49 begin to stop repmgrd on "[192.168.7.248]".
2021-03-01 12:37:50 repmgrd on "[192.168.7.248]" stop success.
2021-03-01 12:37:50 begin to stop repmgrd on "[192.168.7.249]".
2021-03-01 12:37:51 repmgrd on "[192.168.7.249]" stop success.
2021-03-01 12:37:51 begin to stop DB on "[192.168.7.249]".
waiting for server to shut down.... done
server stopped
2021-03-01 12:37:52 DB on "[192.168.7.249]" stop success.
2021-03-01 12:37:52 begin to stop DB on "[192.168.7.248]".
waiting for server to shut down..... done
server stopped
2021-03-01 12:37:53 DB on "[192.168.7.248]" stop success.
2021-03-01 12:37:53 Done.
2021-03-01 12:37:53 Ready to start all DB ...
2021-03-01 12:37:53 begin to start DB on "[192.168.7.248]".
waiting for server to start.... done
server started
2021-03-01 12:37:55 execute to start DB on "[192.168.7.248]" success, connect to check it.
2021-03-01 12:37:56 DB on "[192.168.7.248]" start success.
2021-03-01 12:37:56 Try to ping trusted_servers on host 192.168.7.248 ...
2021-03-01 12:37:59 Try to ping trusted_servers on host 192.168.7.249 ...
2021-03-01 12:38:01 begin to start DB on "[192.168.7.249]".
waiting for server to start.... done
server started
2021-03-01 12:38:03 execute to start DB on "[192.168.7.249]" success, connect to check it.
2021-03-01 12:38:04 DB on "[192.168.7.249]" start success.
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+---------------------------------------------------------------------------------------------------------------------------------------------------
1 | node248 | primary | * running | | default | 100 | 5 | 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 | node249 | standby | running | node248 | default | 100 | 5 | host=192.168.7.249 user=esrep dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2021-03-01 12:38:04 The primary DB is started.
2021-03-01 12:38:08 Success to load virtual ip [192.168.7.240/24] on primary host [192.168.7.248].
2021-03-01 12:38:08 Try to ping vip on host 192.168.7.248 ...
2021-03-01 12:38:11 Try to ping vip on host 192.168.7.249 ...
2021-03-01 12:38:13 begin to start repmgrd on "[192.168.7.248]".
[2021-03-01 12:38:14] [NOTICE] using provided configuration file "/home/kingbase/cluster/R6HA/KHA/kingbase/bin/../etc/repmgr.conf"
[2021-03-01 12:38:14] [NOTICE] redirecting logging output to "/home/kingbase/cluster/R6HA/KHA/kingbase/hamgr.log"
2021-03-01 12:38:14 repmgrd on "[192.168.7.248]" start success.
2021-03-01 12:38:14 begin to start repmgrd on "[192.168.7.249]".
[2021-03-01 12:38:45] [NOTICE] using provided configuration file "/home/kingbase/cluster/R6HA/KHA/kingbase/bin/../etc/repmgr.conf"
[2021-03-01 12:38:45] [NOTICE] redirecting logging output to "/home/kingbase/cluster/R6HA/KHA/kingbase/hamgr.log"
2021-03-01 12:38:15 repmgrd on "[192.168.7.249]" start success.
ID | Name | Role | Status | Upstream | repmgrd | PID | Paused? | Upstream last seen
----+---------+---------+-----------+----------+---------+-------+---------+--------------------
1 | node248 | primary | * running | | running | 14373 | no | n/a
2 | node249 | standby | running | node248 | running | 12219 | no | n/a
2021-03-01 12:38:23 Done.
=== 重新启动集群服务，启动后集群节点状态正常，standby节点删除成功===