Kingbase V8R6集群安装部署案例---脚本在线一键缩容
案例说明：
KingbaseES V8R6支持图形化方式在线缩容，但是在一些生产环境，在服务器不支持图形化界面的情况下 ，只能通过脚本命令行的方式执行集群的部署或在线缩容。
Tips：
KingbaseES V8R6C5默认情况下部署脚本（V8R6_cluster_install.sh）和配置文件（install.conf）不支持在线缩容，需要从KingbaseES V8R6C6版本下拷贝脚本和配置文件到 KingbaseES V8R6C5环境下使用。
适用版本：
KingbaseES V8R6
一、集群节点状态信息
1、主机节点信息
2、缩容前集群节点状态
[kingbase@node101 bin]$ ./repmgr cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------
1 | node101 | primary | * running | | default | 100 | 3 | host=192.168.1.101 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2 | node102 | standby | running | node101 | default | 100 | 3 | host=192.168.1.102 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
3 | node3 | standby | running | node101 | default | 100 | 3 | host=192.168.1.103 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
二、执行集群在线缩容
1、主库节点相关目录和文件
2、在主库节点配置install.conf文件
[kingbase@node101 r6_install]$ cat install.conf |grep -v ^$|grep -v ^#
[install]
on_bmj=0
all_ip=(192.168.1.101 192.168.1.102)
witness_ip=""
production_ip=()
local_disaster_recovery_ip=()
remote_disaster_recovery_ip=()
install_dir="/home/kingbase/cluster/HA_R6/kha/kingbase"
zip_package="/home/kingbase/r6_install/db.zip"
license_file=(license.dat)
db_user="system" # the user name of database
db_port="54321" # the port of database, defaults is 54321
db_mode="oracle" # database mode: pg, oracle
db_auth="scram-sha-256" # database authority: scram-sha-256, md5, default is scram-sha-256
db_case_sensitive="yes" # database case sensitive settings: yes, no. default is yes - case sensitive; no - case insensitive (NOTE. cannot set to 'no' when db_mode="pg").
trusted_servers="192.168.1.1"
data_directory="/home/kingbase/cluster/HA_R6/kha/kingbase/data"
virtual_ip=""
net_device=(enp0s3 enp0s3)
net_device_ip=(192.168.1.101 192.168.1.102)
ipaddr_path="/usr/sbin"
arping_path="/opt/Kingbase/ES/V8R6_041/Server/bin/"
ping_path="/bin"
super_user="root"
execute_user="kingbase"
deploy_by_sshd=1 # choose whether to use sshd when deploy, 0 means not to use (deploy by sys_securecmdd), 1 means to use (deploy by sshd), default value is 1; when on_bmj=1, it will auto set to no(deploy_by_sshd=0)
use_scmd=1 # Is the cluster running on sys_securecmdd or sshd? 1 means yes (on sys_securecmdd), 0 means no (on sshd), default value is 1; when on_bmj=1, it will auto set to yes(use_scmd=1)
reconnect_attempts="10" # the number of retries in the event of an error
reconnect_interval="6" # retry interval
recovery="standby" # the way of cluster recovery: standby/automatic/manual
ssh_port="22" # the port of ssh, default is 22
scmd_port="8890" # the port of sys_securecmdd, default is 8890
auto_cluster_recovery_level='1'
use_check_disk='off'
synchronous='quorum'
########## shrink configure ###############
[shrink]
shrink_type="0" # The node type of standby/witness node, which would be delete from cluster. 0:standby 1:witness
primary_ip="192.168.1.101" # The ip addr of cluster primary node, which need to shrink a standby/witness node.
shrink_ip="192.168.1.103" # The ip addr of standby/witness node, which would be delete from cluster.
node_id="3" # The node_id of standby/witness node, which would be delete from cluster. It does not the same with any one in cluster node
# for example: node_id="3"
install_dir="/home/kingbase/cluster/R6HA/kha"
ssh_port="22" # the port of ssh, default is 22
scmd_port="8899" # the port of sys_securecmd, default is 8890
=如下所示，缩容配置信息，具体说明参考官方文档。=
3、执行在线缩容
[kingbase@node101 r6_install]$ sh V8R6_cluster_install.sh shrink
[CONFIG_CHECK] will deploy the cluster of
[RUNNING] success connect to the target "192.168.1.103" ..... OK
[RUNNING] success connect to "192.168.1.103" from current node by 'ssh' ..... OK
......
2022-07-21 11:04:10 DB on "[localhost]" stop success.
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------
1 | node101 | primary | * running | | default | 100 | 3 | host=192.168.1.101 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2 | node102 | standby | running | node101 | default | 100 | 3 | host=192.168.1.102 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
[Thu Jul 21 11:04:11 CST 2022] [INFO] drop replication slot:repmgr_slot_3...
pg_drop_replication_slot
--------------------------
(1 row)
[Thu Jul 21 11:04:12 CST 2022] [INFO] drop replication slot:repmgr_slot_3...OK
=如上所示，集群缩容成功。=
三、检测集群节点信息
1、查看集群节点状态信息
[kingbase@node101 bin]$ ./repmgr cluster show
ID | Name | Role | Status | Upstream | Location | Priority | Timeline | Connection string
----+---------+---------+-----------+----------+----------+----------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------
1 | node101 | primary | * running | | default | 100 | 3 | host=192.168.1.101 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2 | node102 | standby | running | node101 | default | 100 | 3 | host=192.168.1.102 user=system dbname=esrep port=54321 connect_timeout=10 keepalives=1 keepalives_idle=10 keepalives_interval=1 keepalives_count=3
2、查看主备流复制信息
test=# select * from sys_stat_replication;
pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | back
end_xmin | state | sent_lsn | write_lsn | flush_lsn | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync
_state | reply_time
------+----------+---------+------------------+---------------+-----------------+-------------+-------------------------------+-----
3080 | 10 | system | node102 | 192.168.1.102 | | 12435 | 2022-07-21 09:31:44.710518+08 |
| streaming | 0/930632F0 | 0/930632F0 | 0/930632F0 | 0/930632F0 | | | | 1 | sync
| 2022-07-21 11:15:25.735078+08
(1 row)
3、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 | conf
irmed_flush_lsn
---------------+--------+-----------+--------+----------+-----------+--------+------------+------+--------------+-------------+-----
repmgr_slot_2 | | physical | | | f | t | 3080 | 1620 | | 0/930632F0 |
(1 row)
四、总结
1、KingbaseES V8R6通过脚本缩容操作比较简单，但是KingbaseES V8R6C5自带的脚本和配置文件不支持缩容操作，需要从KingbaseES V8R6C6的软件包下拷贝脚本和配置文件。
2、在集群缩容前保证集群所有节点的状态信息正常，流复制正常。
3、缩容后的节点的相关目录和文件没有被物理删除，需要手工清理 。
