Centos 7 部署 openGauss 3.1.0 級聯備庫集群及集群縮容刪除節點-運維指南

一、安裝環境設置

1.1 硬體環境

1.2 軟體環境

1.2.1 安裝python

-- root用戶【所有節點】
# 本次選擇安裝python 3.6.5版本
mkdir /usr/local/python3
cd /usr/local/python3
wget https://www.python.org/ftp/python/3.6.5/Python-3.6.5.tgz
tar -zxf Python-3.6.5.tgz
cd /usr/local/python3/Python-3.6.5
./configure --prefix=/usr/local/python3 --enable-shared CFLAGS=-fPIC  
make && make install
ln -s /usr/local/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3

-- 設置環境變數
cat >>/etc/profile<<EOF
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/python3/bin
EOF
source /etc/profile
echo "/usr/local/python3/lib/" >> /etc/ld.so.conf
ldconfig

-- 如遇如下報錯
python3: error while loading shared libraries: libpython3.6m.so.1.0: cannot open shared object file: No such file or directory
可執行 cp /usr/local/python3/Python-3.6.5/libpython3.6m.so.1.0 /usr/lib64/

1.2.2 安裝軟體依賴包

1.2.2.1 軟體依賴要求

1.2.2.2 安裝軟體依賴包

-- root用戶 【所有節點】
-- 安裝依賴包
yum install -y libaio-devel flex bison ncurses-devel glibc-devel patch redhat-lsb-core readline-devel zlib readline gcc perl-ExtUtils-Embed readline-devel zlib-devel expect

-- 檢查是否已安裝
rpm -qa --queryformat "%{NAME}-%{VERSION}-%{RELEASE} (%{ARCH})\n" | grep -E "libaio-devel|flex|bison|ncurses-devel|glibc-devel|patch|redhat-lsb-core|readline-devel|zlib|readline|gcc|python|python-devel|perl-ExtUtils-Embed|readline-devel|zlib-devel|expect"

1.2.3 操作系統配置

1.2.3.1 修改操作系統參數

-- root用戶 【所有節點】
-- 添加如下參數：
cat>>/etc/sysctl.conf <<EOF
net.ipv4.tcp_fin_timeout=60
net.ipv4.tcp_retries1=5
net.ipv4.tcp_syn_retries=5
net.sctp.path_max_retrans=10
net.sctp.max_init_retransmits=10
EOF

-- 生效參數
sysctl -p

## 執行sysctl -p 時有如下報錯，此處選擇忽略
sysctl: cannot stat /proc/sys/net/sctp/path_max_retrans: No such file or directory
sysctl: cannot stat /proc/sys/net/sctp/max_init_retransmits: No such file or directory

# 預安裝過程根據系統參數配置會有相應提示，請按照提示對應系統參數

1.2.3.2 修改資源系統限制

-- root用戶 【所有節點】
echo "* soft stack 3072" >> /etc/security/limits.conf
echo "* hard stack 3072" >> /etc/security/limits.conf
echo "* soft nofile 1000000" >> /etc/security/limits.conf
echo "* hard nofile 1000000" >> /etc/security/limits.conf
echo "* soft nproc unlimited" >> /etc/security/limits.d/90-nproc.conf
tail -n 4 /etc/security/limits.conf
tail -n 1 /etc/security/limits.d/90-nproc.conf

1.2.3.3 關閉透明大頁

-- root用戶 【所有節點】
-- openGauss預設關閉使用transparent_hugepage服務，並將關閉命令寫入操作系統啟動文件

cat >> /etc/rc.d/rc.local<<EOF
if test -f /sys/kernel/mm/transparent_hugepage/enabled;
	then
		echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
if test -f /sys/kernel/mm/transparent_hugepage/defrag;
	then
		echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi
EOF

-- 查看是否關閉：
cat /sys/kernel/mm/transparent_hugepage/enabled
cat /sys/kernel/mm/transparent_hugepage/defrag

1.2.3.4 關閉防火牆

-- root用戶 【所有節點】
systemctl disable firewalld.service
systemctl stop firewalld.service

1.2.3.5 關閉selinux

-- root用戶 【所有節點】
sed -i  "s/SELINUX=enforcing/SELINUX=disabled/"  /etc/selinux/config
-- 檢查
cat /etc/selinux/config | grep disabled

1.2.3.6 修改字元集

-- root用戶 【所有節點】
cat>> /etc/profile<<EOF
export LANG=en_US.UTF-8
EOF
source /etc/profile
# 檢查
cat /etc/profile | grep LANG
env |grep -i lang

1.2.3.7 修改時區

-- root用戶 【所有節點】
cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
-- 查看
date 

1.2.3.8 關閉SWAP

-- root用戶 【所有節點】
-- 臨時關閉
swapoff -a

-- 永久關閉
註釋 swap 行
vim /etc/fstab

-- 查看
free -h 查看 swap一行全是 0 表示swap關閉

1.2.3.9 設置網卡MTU

-- root用戶 【所有節點】
-- 設置網卡為1500
ifconfig 網卡名 mtu 1500

-- 查看
ifconfig -a |grep -i mtu

1.2.3.10 設置root用戶遠程登陸

-- root用戶 【所有節點】
cat >>/etc/ssh/sshd_config<<EOF
PermitRootLogin yes
EOF
-- 檢查
cat /etc/ssh/sshd_config |grep PermitRootLogin

1.2.3.11 配置SSH

-- root用戶 【所有節點】
sed -i '/Banner/s/^/#/' /etc/ssh/sshd_config
sed -i '/PermitRootLogin/s/^/#/' /etc/ssh/sshd_config
echo -e "\n" >> /etc/ssh/sshd_config
echo "Banner none " >> /etc/ssh/sshd_config
# 修改Banner配置，去掉連接到系統時，系統提示的歡迎信息。歡迎信息會幹擾安裝時遠程操作的返回結果，影響安裝正常執行
echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
cat /etc/ssh/sshd_config |grep -v ^#|grep -E 'PermitRootLogin|Banner'

-- 重啟生效
systemctl restart sshd.service

1.2.3.12 修改DNS配置

-- root用戶 【所有節點】
-- 節點一
cat >>/etc/resolv.conf<<EOF
nameserver 192.168.17.112
EOF

-- 節點二
cat >>/etc/resolv.conf<<EOF
nameserver 192.168.17.113
EOF

-- 節點三
cat >>/etc/resolv.conf<<EOF
nameserver 192.168.17.139
EOF

-- 節點四
cat >>/etc/resolv.conf<<EOF
nameserver 192.168.17.159
EOF

1.2.3.13 添加hosts解析

-- root用戶 【所有節點】
cat >> /etc/hosts<<EOF
192.168.17.112  opengauss-db1
192.168.17.113  opengauss-db2
192.168.17.139  opengauss-db3
192.168.17.159  opengauss-db4
EOF

二、集群規劃

2.1 主機名-IP地址-埠號規劃

2.2 用戶名規劃

2.3 軟體目錄規劃

三、軟體安裝

3.1 下載軟體包

打開瀏覽器登陸 https://www.opengauss.org/zh/download/ 下載頁面下載 openGauss_3.1.0 Centos_x86_64 對應企業版

3.2 上傳及解壓軟體包

-- 節點一 root 用戶
-- 創建存放安裝包目錄
mkdir -p /opt/software/openGauss
chmod 755 -R /opt/software

-- 上傳軟體包
# 上傳openGauss-3.1.0-CentOS-64bit-all.tar.gz軟體至/opt/software/openGauss目錄
# 解壓軟體包,解壓openGauss-3.1.0-CentOS-64bit-all.tar.gz後需保留 .sha256文件，否則執行預檢查時會報[GAUSS-50201] : The /opt/software/openGauss/openGauss-2.0.0-RedHat-64bit.sha256 does not exist.

tar -zxf openGauss-3.1.0-CentOS-64bit-all.tar.gz

tar -zxf openGauss-3.1.0-CentOS-64bit-om.tar.gz

3.3 創建XML配置文件

3.3.1 配置XML文件

-- 節點一 root 用戶
-- 在/opt/software/openGauss 目錄下創建 clusterconfig.xml配置文件
-- 執行操作如下
cat > clusterconfig.xml<<EOF
<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
    <!-- openGauss整體信息 -->
    <CLUSTER>
    <!-- 資料庫名稱 -->
        <PARAM name="clusterName" value="gsCluster" />
    <!-- 資料庫節點名稱(hostname) -->
        <PARAM name="nodeNames" value="opengauss-db1,opengauss-db2,opengauss-db3,opengauss-db4" />
    <!-- 資料庫安裝目錄-->
        <PARAM name="gaussdbAppPath" value="/opt/gaussdb/install/app" />
    <!-- 日誌目錄-->
        <PARAM name="gaussdbLogPath" value="/opt/gaussdb/log" />
    <!-- 臨時文件目錄-->
        <PARAM name="tmpMppdbPath" value="/opt/gaussdb/tmp"/>
    <!--資料庫工具目錄-->
        <PARAM name="gaussdbToolPath" value="/opt/gaussdb/gausstools/om" />
    <!--資料庫core文件目錄-->
        <PARAM name="corePath" value="/opt/gaussdb/corefile"/>
	<!-- 節點IP，與nodeNames一一對應 -->
        <PARAM name="backIp1s" value="192.168.17.112,192.168.17.113,192.168.17.139,192.168.17.159"/>
    </CLUSTER>
    <!-- 每台伺服器上的節點部署信息 -->
    <DEVICELIST>
        <!-- opengauss-db1上的節點部署信息 -->
        <DEVICE sn="opengauss-db1">
        <!-- opengauss-db1的hostname -->
            <PARAM name="name" value="opengauss-db1"/>
        <!-- opengauss-db1所在的AZ及AZ優先順序 -->
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
        <!-- 如果伺服器只有一個網卡可用，將backIP1和sshIP1配置成同一個IP -->
            <PARAM name="backIp1" value="192.168.17.112"/>
            <PARAM name="sshIp1" value="192.168.17.112"/>
            
        <!--CM-->
     <!--CM數據目錄-->
            <PARAM name="cmDir" value="/opt/gaussdb/install/data/cm" />
            <PARAM name="cmsNum" value="1" />
      <!--CM監聽埠-->
            <PARAM name="cmServerPortBase" value="5000" />
            <PARAM name="cmServerlevel" value="1" />
      <!-- CM所有實例所在節點名及監聽ip -->
      <!-- 添加新增節點IP -->
            <PARAM name="cmServerListenIp1" value="192.168.17.112,192.168.17.113,192.168.17.139,192.168.17.159" />
      <!-- 節點主機名 -->      
            <PARAM name="cmServerRelation" value="opengauss-db1,opengauss-db2,opengauss-db3,opengauss-db4" />
            
      <!-- dbnode -->
        <PARAM name="dataNum" value="1"/>
      <!--DBnode埠號-->
        <PARAM name="dataPortBase" value="26000"/>
      <!-- DBnode主節點上數據目錄，及備機數據目錄 -->
      <!-- 添加新增節點主機名及數據目錄 -->
        <PARAM name="dataNode1" value="/opt/gaussdb/install/data/db1,opengauss-db2,/opt/gaussdb/install/data/db1,opengauss-db3,/opt/gaussdb/install/data/db1,opengauss-db4,/opt/gaussdb/install/data/db1"/>
      <!-- DBnode節點上設定同步模式的節點數 -->
        <PARAM name="dataNode1_syncNum" value="0"/>
        </DEVICE>

        <!-- opengauss-db2上的節點部署信息，其中"name"的值配置為主機名稱(hostname) -->
        <DEVICE sn="opengauss-db2">
            <PARAM name="name" value="opengauss-db2"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- 如果伺服器只有一個網卡可用，將backIP1和sshIP1配置成同一個IP -->
            <PARAM name="backIp1" value="192.168.17.113"/>
            <PARAM name="sshIp1" value="192.168.17.113"/>
            <PARAM name="cmDir" value="/opt/gaussdb/install/data/cm" />
        </DEVICE>

        <!-- opengauss-db3上的節點部署信息，其中"name"的值配置為主機名稱(hostname) -->
        <DEVICE sn="opengauss-db3">
            <PARAM name="name" value="opengauss-db3"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- 如果伺服器只有一個網卡可用，將backIP1和sshIP1配置成同一個IP -->
            <PARAM name="backIp1" value="192.168.17.139"/>
            <PARAM name="sshIp1" value="192.168.17.139"/>
            <PARAM name="cmDir" value="/opt/gaussdb/install/data/cm" />
        </DEVICE>
        
        <!-- 級聯備庫節點信息 -->
		<!-- opengauss-db4上的節點部署信息，其中"name"的值配置為主機名稱(hostname) -->
        <DEVICE sn="opengauss-db4">
            <PARAM name="name" value="opengauss-db4"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- 如果伺服器只有一個網卡可用，將backIP1和sshIP1配置成同一個IP -->
            <PARAM name="backIp1" value="192.168.17.159"/>
            <PARAM name="sshIp1" value="192.168.17.159"/>
            <PARAM name="cmDir" value="/opt/gaussdb/install/data/cm" />
			<!-- opengauss-db4 增加了cascadeRole標識，on 標識該實例為級聯備庫 -->
			<PARAM name="cascadeRole" value="on"/>
        </DEVICE>
    </DEVICELIST>
</ROOT>
EOF

3.3.2 參數簡介

3.4 初始化安裝環境

# root 用戶 節點一主節點操作

-- 設置lib庫
[root@opengauss-db1 ~]# export LD_LIBRARY_PATH=/opt/software/openGauss/script/gspylib/clib:$LD_LIBRARY_PATH

-- 執行預執行
[root@opengauss-db1 ~]# python3 /opt/software/openGauss/script/gs_preinstall -U omm -G dbgrp -X /opt/software/openGauss/clusterconfig.xml

## 執行結果如下
Parsing the configuration file.
Successfully parsed the configuration file.
Installing the tools on the local node.
Successfully installed the tools on the local node.
Are you sure you want to create trust for root (yes/no)?yes  -- 輸入yes
Please enter password for root
Password:     -- 設置 root 口令
Successfully created SSH trust for the root permission user.
Setting host ip env
Successfully set host ip env.
Distributing package.
Begin to distribute package to tool path.
Successfully distribute package to tool path.
Begin to distribute package to package path.
Successfully distribute package to package path.
Successfully distributed package.
Are you sure you want to create the user[omm] and create trust for it (yes/no)? yes -- 輸入yes
Please enter password for cluster user.
Password:    -- 設置 omm 用戶口令
Please enter password for cluster user again.
Password:    -- 重覆輸入 omm 用戶口令
Generate cluster user password files successfully.

Successfully created [omm] user on all nodes.
Preparing SSH service.
Successfully prepared SSH service.
Installing the tools in the cluster.
Successfully installed the tools in the cluster.
Checking hostname mapping.
Successfully checked hostname mapping.
Creating SSH trust for [omm] user.
Please enter password for current user[omm].
Password:   -- 輸入 omm 用戶口令
Checking network information.
All nodes in the network are Normal.
Successfully checked network information.
Creating SSH trust.
Creating the local key file.
Successfully created the local key files.
Appending local ID to authorized_keys.
Successfully appended local ID to authorized_keys.
Updating the known_hosts file.
Successfully updated the known_hosts file.
Appending authorized_key on the remote node.
Successfully appended authorized_key on all remote node.
Checking common authentication file content.
Successfully checked common authentication content.
Distributing SSH trust file to all node.
Distributing trust keys file to all node successfully.
Successfully distributed SSH trust file to all node.
Verifying SSH trust on all hosts.
Successfully verified SSH trust on all hosts.
Successfully created SSH trust.
Successfully created SSH trust for [omm] user.
Checking OS software.
Successfully check os software.
Checking OS version.
Successfully checked OS version.
Creating cluster's path.
Successfully created cluster's path.
Set and check OS parameter.
Setting OS parameters.
Successfully set OS parameters.
Warning: Installation environment contains some warning messages.
Please get more details by "/opt/software/openGauss/script/gs_checkos -i A -h opengauss-db1,opengauss-db2,opengauss-db3,opengauss-db4 --detail".
Set and check OS parameter completed.
Preparing CRON service.
Successfully prepared CRON service.
Setting user environmental variables.
Successfully set user environmental variables.
Setting the dynamic link library.
Successfully set the dynamic link library.
Setting Core file
Successfully set core path.
Setting pssh path
Successfully set pssh path.
Setting Cgroup.
Successfully set Cgroup.
Set ARM Optimization.
No need to set ARM Optimization.
Fixing server package owner.
Setting finish flag.
Successfully set finish flag.
Preinstallation succeeded.

-- 查看預安裝結果信息，並根據預檢查調整參數
-- root 用戶
[root@opengauss-db1 ~]# /opt/software/openGauss/script/gs_checkos -i A -h opengauss-db1,opengauss-db2,opengauss-db3,opengauss-db4 --detail
## 執行結果如下
Checking items:
    A1. [ OS version status ]                                   : Normal     
        [opengauss-db2]
        centos_7.9.2009_64bit
        [opengauss-db1]
        centos_7.9.2009_64bit
        [opengauss-db3]
        centos_7.9.2009_64bit
        [opengauss-db4]
        centos_7.9.2009_64bit

    A2. [ Kernel version status ]                               : Normal     
        The names about all kernel versions are same. The value is "3.10.0-693.el7.x86_64".
    A3. [ Unicode status ]                                      : Normal     
        The values of all unicode are same. The value is "LANG=en_US.UTF-8".
    A4. [ Time zone status ]                                    : Normal     
        The informations about all timezones are same. The value is "+0800".
    A5. [ Swap memory status ]                                  : Normal     
        The value about swap memory is correct.            
    A6. [ System control parameters status ]                    : Normal     
        All values about system control  parameters are correct.
    A7. [ File system configuration status ]                    : Normal     
        Both soft nofile and hard nofile are correct.      
    A8. [ Disk configuration status ]                           : Normal     
        The value about XFS mount parameters is correct.   
    A9. [ Pre-read block size status ]                          : Normal     
        The value about Logical block size is correct.     
    A10.[ IO scheduler status ]                                 : Normal     
        The value of IO scheduler is correct.              
    A11.[ Network card configuration status ]                   : Warning    
        [opengauss-db1]
BondMode Null
        Warning reason: network 'ens33' 'mtu' RealValue '1500' ExpectedValue '8192' -- 可忽略

        [opengauss-db2]
BondMode Null
        Warning reason: network 'ens33' 'mtu' RealValue '1500' ExpectedValue '8192' -- 可忽略

        [opengauss-db3]
BondMode Null
        Warning reason: network 'ens33' 'mtu' RealValue '1500' ExpectedValue '8192' -- 可忽略

        [opengauss-db4]
BondMode Null
        Warning reason: network 'ens33' 'mtu' RealValue '1500' ExpectedValue '8192' -- 可忽略


    A12.[ Time consistency status ]                             : Warning    
        [opengauss-db2]
        The NTPD not detected on machine and local time is "2022-11-14 17:08:56".
        [opengauss-db1]
        The NTPD not detected on machine and local time is "2022-11-14 17:08:56".
        [opengauss-db3]
        The NTPD not detected on machine and local time is "2022-11-14 17:08:56".
        [opengauss-db4]
        The NTPD not detected on machine and local time is "2022-11-14 17:08:56".

    A13.[ Firewall service status ]                             : Normal     
        The firewall service is stopped.                   
    A14.[ THP service status ]                                  : Normal     
        The THP service is stopped.                        
Total numbers:14. Abnormal numbers:0. Warning numbers:2.
-- 根據執行detail命令結果對預檢查告警進行調整

3.5 執行集群安裝

3.5.1 修改屬主

-- 務必確保已在節點一執行預檢查
-- root 用戶 節點一操作
[root@opengauss-db1 ~]# chmod -R 755 /opt/software/openGauss/script/
[root@opengauss-db1 ~]# chown -R omm:dbgrp /opt/software/openGauss/script/

3.5.2 執行集群安裝

-- 節點一切換到omm用戶執行
[root@opengauss-db1 ~]# su - omm
-- 執行如下命令
[omm@opengauss-db1 ~]$ gs_install -X /opt/software/openGauss/clusterconfig.xml
## 執行結果如下
Parsing the configuration file.
Check preinstall on every node.
Successfully checked preinstall on every node.
Creating the backup directory.
Successfully created the backup directory.
begin deploy..
Installing the cluster.
begin prepare Install Cluster..
Checking the installation environment on all nodes.
begin install Cluster..
Installing applications on all nodes.
Successfully installed APP.
begin init Instance..
encrypt cipher and rand files for database.
Please enter password for database:    -- 設置資料庫 口令 如 Passw0rd@1234
Please repeat for database:            -- 再次輸入相同口令
begin to create CA cert files
The sslcert will be generated in /opt/gaussdb/install/app/share/sslcert/om
Create CA files for cm beginning.
Create CA files on directory [/opt/gaussdb/install/app_4e931f9a/share/sslcert/cm]. file list: ['client.key.rand', 'server.crt', 'cacert.pem', 'client.crt', 'server.key.rand', 'client.key', 'client.key.cipher', 'server.key', 'server.key.cipher']
Cluster installation is completed.
Configuring.
Deleting instances from all nodes.
Successfully deleted instances from all nodes.
Checking node configuration on all nodes.
Initializing instances on all nodes.
Updating instance configuration on all nodes.
Check consistence of memCheck and coresCheck on database nodes.
Successful check consistence of memCheck and coresCheck on all nodes.
Configuring pg_hba on all nodes.
Configuration is completed.
Starting cluster.
======================================================================
Successfully started primary instance. Wait for standby instance.
======================================================================
.
Successfully started cluster.
======================================================================
cluster_state      : Normal
redistributing     : No
node_count         : 4
Datanode State
    primary           : 1
    standby           : 2
    secondary         : 0
    cascade_standby   : 1
    building          : 0
    abnormal          : 0
    down              : 0

Successfully installed application.
end deploy..

3.5.3 資料庫狀態檢查

-- omm 用戶
[omm@opengauss-db1 ~]$ gs_om -t status --detail
[  CMServer State   ]

node             node_ip         instance                                    state
------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  1    /opt/gaussdb/install/data/cm/cm_server Primary
2  opengauss-db2 192.168.17.113  2    /opt/gaussdb/install/data/cm/cm_server Standby
3  opengauss-db3 192.168.17.139  3    /opt/gaussdb/install/data/cm/cm_server Standby
4  opengauss-db4 192.168.17.159  4    /opt/gaussdb/install/data/cm/cm_server Standby

[   Cluster State   ]

cluster_state   : Normal
redistributing  : No
balanced        : Yes
current_az      : AZ_ALL

[  Datanode State   ]

node             node_ip         instance                           state            
-------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  6001 /opt/gaussdb/install/data/db1 P Primary Normal
2  opengauss-db2 192.168.17.113  6002 /opt/gaussdb/install/data/db1 S Standby Normal
3  opengauss-db3 192.168.17.139  6003 /opt/gaussdb/install/data/db1 S Standby Normal
4  opengauss-db4 192.168.17.159  6004 /opt/gaussdb/install/data/db1 C Cascade Standby Normal

3.5.4 集群狀態檢查

-- omm 用戶
[omm@opengauss-db1 ~]$ cm_ctl query -v -C -i -d
[  CMServer State   ]

node             node_ip         instance                                    state
------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  1    /opt/gaussdb/install/data/cm/cm_server Primary
2  opengauss-db2 192.168.17.113  2    /opt/gaussdb/install/data/cm/cm_server Standby
3  opengauss-db3 192.168.17.139  3    /opt/gaussdb/install/data/cm/cm_server Standby
4  opengauss-db4 192.168.17.159  4    /opt/gaussdb/install/data/cm/cm_server Standby

[   Cluster State   ]

cluster_state   : Normal
redistributing  : No
balanced        : Yes
current_az      : AZ_ALL

[  Datanode State   ]

node             node_ip         instance                           state            
-------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  6001 /opt/gaussdb/install/data/db1 P Primary Normal 
2  opengauss-db2 192.168.17.113  6002 /opt/gaussdb/install/data/db1 S Standby Normal
3  opengauss-db3 192.168.17.139  6003 /opt/gaussdb/install/data/db1 S Standby Normal      
4  opengauss-db4 192.168.17.159  6004 /opt/gaussdb/install/data/db1 C Cascade Standby Normal

3.6 查詢級聯備庫日誌接收狀態

-- omm 用戶 級聯備庫操作
[root@opengauss-db4 ~]# su - omm
Last login: Mon Nov 14 17:05:30 CST 2022
[omm@opengauss-db4 ~]$ gsql -d postgres -p 26000
gsql ((openGauss 3.1.0 build 4e931f9a) compiled at 2022-09-29 14:19:24 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
openGauss=# \x
Expanded display is on.
openGauss=# select * from pg_stat_get_wal_receiver();

四、集群縮容

4.1 查詢集群狀態

-- omm 用戶
[omm@opengauss-db1 ~]$ gs_om -t status --detail
[  CMServer State   ]

node             node_ip         instance                                    state
------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  1    /opt/gaussdb/install/data/cm/cm_server Primary
2  opengauss-db2 192.168.17.113  2    /opt/gaussdb/install/data/cm/cm_server Standby
3  opengauss-db3 192.168.17.139  3    /opt/gaussdb/install/data/cm/cm_server Standby
4  opengauss-db4 192.168.17.159  4    /opt/gaussdb/install/data/cm/cm_server Standby

[   Cluster State   ]

cluster_state   : Normal
redistributing  : No
balanced        : Yes
current_az      : AZ_ALL

[  Datanode State   ]

node             node_ip         instance                           state            
-------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  6001 /opt/gaussdb/install/data/db1 P Primary Normal
2  opengauss-db2 192.168.17.113  6002 /opt/gaussdb/install/data/db1 S Standby Normal
3  opengauss-db3 192.168.17.139  6003 /opt/gaussdb/install/data/db1 S Standby Normal
4  opengauss-db4 192.168.17.159  6004 /opt/gaussdb/install/data/db1 C Cascade Standby Normal

4.2 縮容節點

-- omm 用戶 主節點操作
[omm@opengauss-db1 ~]$ gs_dropnode -U omm -G dbgrp -h 192.168.17.159
-- 執行結果如下
The target node to be dropped is (['opengauss-db4']) 
Do you want to continue to drop the target node (yes/no)?yes   -- 輸入 yes
Drop node start with CM node.
Drop node with CM node is running.
[gs_dropnode]Start to drop nodes of the cluster.
[gs_dropnode]Start to stop the target node opengauss-db4.
[gs_dropnode]End of stop the target node opengauss-db4.
[gs_dropnode]Start to backup parameter config file on opengauss-db1.
[gs_dropnode]End to backup parameter config file on opengauss-db1.
[gs_dropnode]The backup file of opengauss-db1 is /opt/gaussdb/tmp/gs_dropnode_backup20221114182028/parameter_opengauss-db1.tar
[gs_dropnode]Start to parse parameter config file on opengauss-db1.
[gs_dropnode]End to parse parameter config file on opengauss-db1.
[gs_dropnode]Start to parse backup parameter config file on opengauss-db1.
[gs_dropnode]End to parse backup parameter config file opengauss-db1.
[gs_dropnode]Start to set openGauss config file on opengauss-db1.
[gs_dropnode]End of set openGauss config file on opengauss-db1.
[gs_dropnode]Start to backup parameter config file on opengauss-db2.
[gs_dropnode]End to backup parameter config file on opengauss-db2.
[gs_dropnode]The backup file of opengauss-db2 is /opt/gaussdb/tmp/gs_dropnode_backup20221114182030/parameter_opengauss-db2.tar
[gs_dropnode]Start to parse parameter config file on opengauss-db2.
[gs_dropnode]End to parse parameter config file on opengauss-db2.
[gs_dropnode]Start to parse backup parameter config file on opengauss-db2.
[gs_dropnode]End to parse backup parameter config file opengauss-db2.
[gs_dropnode]Start to set openGauss config file on opengauss-db2.
[gs_dropnode]End of set openGauss config file on opengauss-db2.
[gs_dropnode]Start to backup parameter config file on opengauss-db3.
[gs_dropnode]End to backup parameter config file on opengauss-db3.
[gs_dropnode]The backup file of opengauss-db3 is /opt/gaussdb/tmp/gs_dropnode_backup20221114182036/parameter_opengauss-db3.tar
[gs_dropnode]Start to parse parameter config file on opengauss-db3.
[gs_dropnode]End to parse parameter config file on opengauss-db3.
[gs_dropnode]Start to parse backup parameter config file on opengauss-db3.
[gs_dropnode]End to parse backup parameter config file opengauss-db3.
[gs_dropnode]Start to set openGauss config file on opengauss-db3.
[gs_dropnode]End of set openGauss config file on opengauss-db3.
[gs_dropnode]Start of set pg_hba config file on opengauss-db1.
[gs_dropnode]End of set pg_hba config file on opengauss-db1.
[gs_dropnode]Start of set pg_hba config file on opengauss-db2.
[gs_dropnode]End of set pg_hba config file on opengauss-db2.
[gs_dropnode]Start of set pg_hba config file on opengauss-db3.
[gs_dropnode]End of set pg_hba config file on opengauss-db3.
[gs_dropnode]Start to set repl slot on opengauss-db1.
[gs_dropnode]Start to get repl slot on opengauss-db1.
[gs_dropnode]End of set repl slot on opengauss-db1.
Stopping node.
=========================================
Successfully stopped node.
=========================================
End stop node.
Generate drop flag file on drop node opengauss-db4 successfully.
[gs_dropnode]Start to modify the cluster static conf.
[gs_dropnode]End of modify the cluster static conf.
Restart cluster ...
Stopping cluster.
=========================================
Successfully stopped cluster.
=========================================
End stop cluster.
Remove dynamic_config_file and CM metadata directory on all nodes.
Starting cluster.
======================================================================
Successfully started primary instance. Wait for standby instance.
======================================================================
.
Successfully started cluster.
======================================================================
cluster_state      : Normal
redistributing     : No
node_count         : 3
Datanode State
    primary           : 1
    standby           : 2
    secondary         : 0
    cascade_standby   : 0
    building          : 0
    abnormal          : 0
    down              : 0

Failed to reset switchover the cluster. Command: "source /home/omm/.bashrc ; cm_ctl switchover -a -t 0".
Output: "cm_ctl: create ssl connection failed.
cm_ctl: socket is [4], 462 : create ssl failed: 
cm_ctl: send switchover msg to cm_server, connect fail node_id:0, data_path:.".
[gs_dropnode] Success to drop the target nodes.

4.3 再次查詢集群狀態

-- omm 用戶
[omm@opengauss-db1 ~]$ gs_om -t status --detail
[  CMServer State   ]

node             node_ip         instance                                    state
------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  1    /opt/gaussdb/install/data/cm/cm_server Primary
2  opengauss-db2 192.168.17.113  2    /opt/gaussdb/install/data/cm/cm_server Standby
3  opengauss-db3 192.168.17.139  3    /opt/gaussdb/install/data/cm/cm_server Standby

[   Cluster State   ]

cluster_state   : Normal
redistributing  : No
balanced        : Yes
current_az      : AZ_ALL

[  Datanode State   ]

node             node_ip         instance                           state            
-------------------------------------------------------------------------------------
1  opengauss-db1 192.168.17.112  6001 /opt/gaussdb/install/data/db1 P Primary Normal
2  opengauss-db2 192.168.17.113  6002 /opt/gaussdb/install/data/db1 S Standby Normal
3  opengauss-db3 192.168.17.139  6003 /opt/gaussdb/install/data/db1 S Standby Normal

4.4 刪除SSH互信

-- omm 用戶，被縮容節點操作
[root@opengauss-db4 ~]# mv .ssh .ssh_back
[root@opengauss-db4 ~]# su - omm
Last login: Mon Nov 14 17:33:17 CST 2022 on pts/0
[omm@opengauss-db4 ~]$ mv .ssh .ssh_back

4.5 清理備庫數據

-- omm 用戶 在被清理備庫伺服器操作
[root@opengauss-db4 ~]# su - omm
Last login: Mon Nov 14 18:28:56 CST 2022 on pts/3
[omm@opengauss-db4 ~]$ gs_uninstall --delete-data -L
This is a node where the gs_dropnode command has been executed. Uninstall a single node instead of the gs_dropnode command.
Checking uninstallation.
Successfully checked uninstallation.
Stopping the cluster.
Successfully stopped local node.
Successfully deleted instances.
Uninstalling application.
Successfully uninstalled application.
Uninstallation succeeded.

4.6 清理備庫軟體

-- 拷貝主庫 /opt/software/openGauss/script 目錄至被清理備庫
[root@opengauss-db1 ~]# cd /opt/software/openGauss/script/
[root@opengauss-db1 script]# scp * root@opengauss-db4:/opt/software/openGauss/script/

-- root 用戶 在被清理備庫操作執行清理備庫軟體及目錄
[root@opengauss-db4 ~]# cd /opt/software/openGauss/script/
[root@opengauss-db4 script]# ./gs_postuninstall -U omm -X /opt/software/openGauss/clusterconfig.xml --delete-user --delete-group -L
Parsing the configuration file.
Successfully parsed the configuration file.
Check log file path.
Successfully checked log file path.
Checking unpreinstallation.
Successfully checked unpreinstallation.
Deleting the instance's directory.
Successfully deleted the instance's directory.
Deleting the temporary directory.
Successfully deleted the temporary directory.
Deleting software packages and environmental variables of the local node.
Successfully deleted software packages and environmental variables of the local nodes.
Deleting local OS user.
Successfully deleted local OS user.
Deleting local node's logs.
Successfully deleted local node's logs.
Successfully cleaned environment.

4.7 清理備庫目錄

-- 根據clusterconfig.xml文件，清理備庫相應目錄
[root@opengauss-db4 opt]# rm -rf /opt/gaussdb/
[root@opengauss-db4 ~]# rm -rf /root/gauss*