Installing MogDB

Creating an XML Configuration File

Before installing MogDB, you need to create the XML file. The XML file contains the information about the server where MogDB is deployed, installation path, IP address, and port number. This file is used to guide how to deploy the MogDB. You need to configure the XML configuration file according to the actual deployment requirements.

Parameter description

Instance Type	Parameter	Description
Overall information
	clusterName	MogDB name.
	nodeNames	Host name in the MogDB.
	backIp1s	Intranet IP address of the host in the backend storage network. All the MogDB hosts communicate with each other on this network.
	gaussdbAppPath	Installation directory of the MogDB program. This directory must meet the following requirements: - The disk space is greater than 1 GB. - This directory is independent of other directories required by the database.
	gaussdbLogPath	Directory that stores run logs and operation logs of the MogDB. This directory must meet the following requirements: - You are advised to plan the disk space based on the number of database nodes on the host. Reserve 1 GB space for database nodes and reserve redundant space. - This directory is independent of other directories required by the MogDB. This directory is optional. If the directory is not specified, $GAUSSLOG/installation uername will be specified as the log directory by default during MogDB installation.
	tmpdbPath	Directory for storing temporary database files. If tmpdbPath is not set, the file is stored in /opt/mogdb/tools/perfadm_db by default.
	gaussdbToolPath	Directory for storing MogDB system tools. This directory is used to store tools for mutual trust. This directory must meet the following requirements: - The disk space is greater than 100 MB. - This directory cannot be changed and is independent of other directories required by the database. This directory is optional. If this parameter is not specified, /opt/mogdb/tools is specified as the database system tool directory by default during MogDB installation.
	corePath	Directory for storing the MogDB core file.
	clusterType	MogDB type cluster type. This parameter is optional. single-inst indicates the standalone cluster with one primary node and multiple standby nodes.

Example

Configuration File for Single-Instance Deployment

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
    <!-- Overall information about MogDB -->
    <CLUSTER>
        <PARAM name="clusterName" value="dbCluster" />
        <PARAM name="nodeNames" value="node1" />
        <PARAM name="backIp1s" value="192.168.0.11"/>
        <PARAM name="gaussdbAppPath" value="/opt/mogdb/app" />
        <PARAM name="gaussdbLogPath" value="/var/log/mogdb" />
        <PARAM name="gaussdbToolPath" value="/opt/mogdb/tools" />
        <PARAM name="corePath" value="/opt/mogdb/corefile"/>
        <PARAM name="clusterType" value="single-inst"/>
    </CLUSTER>

<!-- Information about node deployment on each server  -->
    <DEVICELIST>
        <!-- Information about the node deployment on node1  -->
        <DEVICE sn="1000001">
            <PARAM name="name" value="node1"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.11"/>
            <PARAM name="sshIp1" value="192.168.0.11"/>

        <!--dbnode-->
        <PARAM name="dataNum" value="1"/>
        <PARAM name="dataPortBase" value="26000"/>
        <PARAM name="dataNode1" value="/mogdb/data/db1"/>
        </DEVICE>
    </DEVICELIST>
</ROOT>

Note: The host name and IP address need to be replaced. For other parameters, retain the default values.

Configuration File for One Primary and One Standby

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
    <!-- Overall information about MogDB -->
    <CLUSTER>
        <PARAM name="clusterName" value="dbCluster" />
        <PARAM name="nodeNames" value="node1,node2" />
        <PARAM name="backIp1s" value="192.168.0.11,192.168.0.12"/>
        <PARAM name="gaussdbAppPath" value="/opt/mogdb/app" />
        <PARAM name="gaussdbLogPath" value="/var/log/mogdb" />
        <PARAM name="gaussdbToolPath" value="/opt/mogdb/tools" />
        <PARAM name="corePath" value="/opt/mogdb/corefile"/>
        <PARAM name="clusterType" value="single-inst"/>
    </CLUSTER>
    <!-- Information about node deployment on each server -->
    <DEVICELIST>
        <!-- Information about the node deployment on node1 -->
        <DEVICE sn="1000001">
            <PARAM name="name" value="node1"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.11"/>
            <PARAM name="sshIp1" value="192.168.0.11"/>

        <!--dbnode-->
        <PARAM name="dataNum" value="1"/>
        <PARAM name="dataPortBase" value="26000"/>
        <PARAM name="dataNode1" value="/mogdb/data/db1,node2,/mogdb/data/db1"/>
        </DEVICE>

        <!-- Node deployment information on node2. The value of name is the host name.  -->
        <DEVICE sn="1000002">
            <PARAM name="name" value="node2"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.12"/>
            <PARAM name="sshIp1" value="192.168.0.12"/>
    </DEVICE>
    </DEVICELIST>
</ROOT>

Note: The host name and IP address need to be replaced. For other parameters, retain the default values.

Configuration File for One Primary and Two Standbys

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
    <!-- Overall information about MogDB -->
    <CLUSTER>
        <PARAM name="clusterName" value="dbCluster" />
        <PARAM name="nodeNames" value="node1,node2,node3" />
        <PARAM name="backIp1s" value="192.168.0.11,192.168.0.12, 192.168.0.13"/>
        <PARAM name="gaussdbAppPath" value="/opt/mogdb/app" />
        <PARAM name="gaussdbLogPath" value="/var/log/mogdb" />
        <PARAM name="gaussdbToolPath" value="/opt/mogdb/tools" />
        <PARAM name="corePath" value="/opt/mogdb/corefile"/>
        <PARAM name="clusterType" value="single-inst"/>
    </CLUSTER>
    <!-- Information about node deployment on each server -->
    <DEVICELIST>
        <!-- Information about the node deployment on node1 -->
        <DEVICE sn="1000001">
            <PARAM name="name" value="node1"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.11"/>
            <PARAM name="sshIp1" value="192.168.0.11"/>

        <!--dbnode-->
        <PARAM name="dataNum" value="1"/>
        <PARAM name="dataPortBase" value="26000"/>
        <PARAM name="dataNode1" value="/mogdb/data/db1,node2,/mogdb/data/db1, node3,/mogdb/data/db1"/>
        </DEVICE>

        <!-- Node deployment information on node2. The value of name is the host name.  -->
        <DEVICE sn="1000002">
            <PARAM name="name" value="node2"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.12"/>
            <PARAM name="sshIp1" value="192.168.0.12"/>
    </DEVICE>
        <!--Node deployment information on node3. The value of name is the host name.  -->
        <DEVICE sn="1000003">
            <PARAM name="name" value="node3"/>
            <PARAM name="azName" value="AZ1"/>
            <PARAM name="azPriority" value="1"/>
            <!-- If only one NIC is available for the server, set backIP1 and sshIP1 to the same IP address. -->
            <PARAM name="backIp1" value="192.168.0.13"/>
            <PARAM name="sshIp1" value="192.168.0.13"/>
    </DEVICE>
    </DEVICELIST>
</ROOT>

Note: The host name and IP address need to be replaced. For other parameters, retain the default values. /mogdb/data/db1 indicates the directory for storing data. You can replace the directory according to the actual environment requirement.

Downloading an Installation Package

Before installation, you can visit MogDB download page to download the installation package applicable to your current operating system and CPU. The following takes the CentOS system as an example. Each installation package and its functions are introduced in the following table.

Package	Function
MogDB-2.0.3-CentOS-all-x86_64.tar	Contains all files of all installation packages
MogDB-2.0.3-CentOS-64bit.tar.bz2	(Primary/Standby) MogDB primary/standby (Datanode). Stores business data, performs data query tasks, and returns execution results to the client. MogDB instances include primary instance and standby instance, currently supports at most one primary node and eight standby nodes. It is recommended to deploy the primary and standby MogDB instances on different physical servers.
MogDB-2.0.3-CentOS-64bit.sha256	Hash value of sha256 of MogDB-2.0.3-CentOS-64bit.tar.bz2
MogDB-2.0.3-CentOS-64bit-Libpq.tar.gz	Driver for C program to access MogDB database
MogDB-2.0.3-CentOS-64bit-om.tar.gz	Operation and maintenance management module (Operation Manager). Provides management interfaces and tools for daily database operation and maintenance and configuration management.
MogDB-2.0.3-CentOS-64bit-om.sha256	Hash value of sha256 of MogDB-2.0.3-CentOS-64bit-om.tar.gz
MogDB-2.0.3-CentOS-64bit-tools.tar.gz	Client Driver. Receives the access request from the application and returns the execution result to the application. The client driver is used for communicating with the MogDB instance, sending application SQL commands, and receiving the execution results of the MogDB instance.
upgrade_sql.tar.gz	SQL commands required for the upgrade
upgrade_sql.sha256	Hash value of sha256 of upgrade_sql.tar.gz

Initializing the Environment

This section takes the CentOS OS as an example to describe the environment initialization process.

Procedure

Run the following command as user root to install the required environment dependency packages.

yum install -y bzip2 libaio-devel flex bison ncurses-devel glibc-devel libxml2-devel patch redhat-lsb-core unzip gcc gcc-c++ perl openssl-devel libffi-devel libtool zlib-devel

Log in to any host where the MogDB is to be installed as user root and create a directory for storing the installation package as planned.
```
mkdir -p /opt/software/mogdb
chmod 755 -R /opt/software
```
Upload the software package MogDB-2.0.3-CentOS-x86_64.tar and the configuration file clusterconfig.xml to the created directory. If the configuration file is not created, run the vi clusterconfig.xml command to create and edit the configuration file.
```
cd /opt/software/mogdb
```
Note: In environments that allow access to external networks, the installation package can be downloaded directly via the wget command. For example:
```
wget -c https://cdn-mogdb.enmotech.com/mogdb-media/2.0.3/MogDB-2.0.3-CentOS-x86_64.tar
```

Go to the directory for storing the uploaded software package and decompress the following packages in sequence.

cd /opt/software/mogdb
tar -xvf  MogDB-2.0.3-CentOS-x86_64.tar
tar -xvf  MogDB-2.0.3-CentOS-64bit-om.tar.gz
tar -xf  MogDB-2.0.3-CentOS-64bit.tar.bz2

Go to the directory for storing tool scripts.
```
cd /opt/software/mogdb/script
```
To ensure that the openssl version is correct, upload the lib library in the software package before pre-installation. Run the following command. {packagePath} indicates the directory where the software package is located. The value is /opt/software/mogdb in this example.
```
export LD_LIBRARY_PATH={packagePath}/script/gspylib/clib:$LD_LIBRARY_PATH
```
To ensure successful installation, run the following command to check whether the values of hostname and /etc/hostname are the same. During the pre-installation, hostname will be checked.
```
hostname
vi /etc/hostname
```
If the openEuler OS is used, comment out sysctl -w vm.min_free_kbytes=112640 &> /dev/null in the performance.sh file.
```
vi /etc/profile.d/performance.sh
```
Install python3 for the CentOS.

Note: For standard installation in the CentOS system, you must install Python 3.6.x. Python of a higher version is not supported currently.
```
wget https://www.python.org/ftp/python/3.6.5/Python-3.6.5.tgz
mkdir -p /usr/local/python3
tar -zxvf Python-3.6.5.tgz
cd 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
```
Note:
- If the error "zipimport.ZipImportError: can't decompress data; zlib not available" is reported, run the yum -y install zlib* command and install again.
- If an error similar to "find:'/run/user/1000/gvfs':Permission denied" is reported, it can be ignored.

Initializing the Script

/opt/software/mogdb/script/gs_preinstall -U omm -G dbgrp -X /opt/software/mogdb/clusterconfig.xml

Parsing the configuration file.
Successfully parsed the configuration file.
Installing the tools on the local node.
Successfully installed the tools on the local node.
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.
Installing the tools in the cluster.
Successfully installed the tools in the cluster.
Checking hostname mapping.
Successfully checked hostname mapping.
Checking OS version.
Successfully checked OS version.
Creating cluster's path.
Successfully created cluster's path.
Setting SCTP service.
Successfully set SCTP service.
Set and check OS parameter.
Setting OS parameters.
Successfully set OS parameters.
Set and check OS parameter completed.
Preparing CRON service.
Successfully prepared CRON service.
Preparing SSH service.
Successfully prepared SSH service.
Setting user environmental variables.
Successfully set user environmental variables.
Configuring alarms on the cluster nodes.
Successfully configured alarms on the cluster nodes.
Setting the dynamic link library.
Successfully set the dynamic link library.
Setting Cgroup.
Successfully set Cgroup.
Set ARM Optimization.
Successfully set ARM Optimization.
Setting finish flag.
Successfully set finish flag.
Preinstallation succeeded.

Note:
During the running, the system will ask whether to create the user omm, you need to enter yes. Additionally, you need to enter related passwords and make sure that the password complexity requirement is met, including uppercase and lower case letters, characters, and digits, such as Enmo@123.
If an error similar to the following is displayed, the version of Python is high.
[root@localhost mogdb]# /opt/software/mogdb/script/gs_preinstall -U omm -G dbgrp -X /mogdb/etc/mogdb_clusterconfig.xml
Failed to execute cmd: rm -rf '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_linux.so' && cp -r '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_linux.so_3.9' '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_linux.so' && rm -rf '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_posix.so' && cp -r '/opt/software/mogdb/script/gspylib/os/./../../../lib /psutil/_psutil_posix.so_3.9' '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_posix.so' . Error:
cp: cannot stat '/opt/software/mogdb/script/gspylib/os/./../../../lib/psutil/_psutil_linux.so_3.9': No such file or directory

Performing the Installation

su - omm
gs_install -X /opt/software/mogdb/clusterconfig.xml --gsinit-parameter="--locale=en_US.UTF-8" --gsinit-parameter="--encoding=UTF-8"

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 ciper and rand files for database.
Please enter password for database:
Please repeat for database:
begin to create CA cert files
The sslcert will be generated in /opt/mogdb/cluster/app/share/sslcert/om
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 DN nodes.
Successful check consistence of memCheck and coresCheck on all nodes.
Configuring pg_hba on all nodes.
Configuration is completed.
Successfully started cluster.
Successfully installed application.

Note: During the installation, the user needs to enter the password of the database as prompted. The password must meet the complexity requirement. To ensure that the user can use the database normally, make note of the database password.

Connecting To MogDB

After installation, you can connect to MogDB by running gsql -d postgres -p 26000 -r under the omm user, where -p 26000 is the database port number. You need to replace it according to the actual situation. Additionally, you can run the \copyright command to check the copyright information.

[omm@ecs-saving-0006 ~]$ gsql -d postgres -p 26000 -r
gsql ((MogDB 2.0.3 build f892ccb7) compiled at 2021-07-09 16:12:59 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

postgres=# \copyright
MogDB Kernel Database Management System
Copyright (c) Yunhe Enmo (Beijing) Information Technology Co., Ltd. Copyright © 2009-2021 , All rights reserved.

Modifying the Synchronous Node

By default, the standby database is an asynchronous database. If you need to configure it as a synchronous database, configure it as follows:

[omm@ecs-saving-0006 ~]$ sed -i "/synchronous_standby_names/synchronous_standby_names = 'dn_6002'" /gaussdb/data/db1/postgresql.conf
[omm@ecs-saving-0006 ~]$ gs_om -t restart

The value dn_6002 is special, which is fixed. It is dn_6001 for the primary database, dn_6002 for the first standby database, and dn_6003 for the second standby database in sequence.

'dn_6002,dn_6003' indicates that the first and second standby databases are synchronous databases.

The data storing directory needs to be replaced as required.