Common Installation Tasks

These tasks are performed on all DB servers, no matter what role (master or slave) they are to perform.

Attach STORE

First of all, the STORE is connected to the machine, as described here: Mounting STORE - All Linux except for STORE (CentOS8/Win2019)

Install MySQL

Configure Repositories and Install mysql-community-server

CentOS 8.x comes with some default repositories, which we do not want. These are disabled, and the MySQL repository is installed. Then the MySQL Server is installed.

# Make sure liibaio is on
dnf -y install libaio

# Disable some default stuff
dnf config-manager --disable mysql-connectors-community
dnf config-manager --disable mysql-tools-community
dnf -y module disable mysql

# Install the Oracle MySQL repo and the client
dnf -y install https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm
dnf -y install mysql-community-server

Start MySQL

Next, the MySQL server is configured to autostart on boot, and started up:

systemctl enable mysqld.service
systemctl start mysqld.service

Configure Firewall

Access to the MySQL Server is configured in the firewall:

firewall-cmd --zone=public --add-port=3306/tcp --permanent
firewall-cmd --reload

Configure MySQL

Configuration Files

MySQL 8.x creates a configuration directory /etc/my.cnf.d when it installs. The jtel configuration files are stored here, but a reference must be added to this directory so that mysql loads the configuration files.

This is added with the following command:

cat <<EOFF >> /etc/my.cnf
#
# * IMPORTANT: Additional settings that can override those from this file!
# The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/my.cnf.d/
EOFF

The next command downloads the main configuration file for the mysql server. This file contains a lot of well commented settings which can be tweaked if required. The main parameter to be changed is the RAM usage of the sever. See below.

wget -P /etc/my.cnf.d http://cdn.jtel.de/downloads/configs/jtel-enhanced-8.cnf

Restart Server

Now, the MySQL must be restarted:

systemctl restart mysqld.service

Configure Users

After the first restart, user access must be setup.

MySQL 8.x saves a generated random password for the root user in the file /var/log/mysqld.log

This password must be extracted. Often, it contains special characters which cannot be input on the command line within a script. For the following command the password is input manually. Note, that <password> refers to the NEW password you want to assign to the root account.

CAUTION PASSWORD

mysqladmin -u root -p password '<password>'

The following commands configure the further users required:

CAUTION PASSWORD

mysql -u root -p<password> -v -e"CREATE USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '<password>'"
mysql -u root -p<password> -v -e"GRANT ALL ON *.* TO 'root'@'%' WITH GRANT OPTION"
mysql -u root -p<password> -v -e"FLUSH PRIVILEGES"

Install UDP Plugin

Next, the UDP plugin is installed. This is required for the communication with further software modules in the system, when certain DB changes are made.

The installation is slightly different for master and slave servers.

Installation

Master Server

cp /home/jtel/shared/JTELCarrierPortal/Libraries/jtel_udf_udpsend/jtel_udf_udpsend.so /usr/lib64/mysql/plugin/
chown root:root /usr/lib64/mysql/plugin/jtel_udf_udpsend.so
chmod 755 /usr/lib64/mysql/plugin/jtel_udf_udpsend.so
chcon system_u:object_r:lib_t:s0  /usr/lib64/mysql/plugin/jtel_udf_udpsend.so

Slave Server

cp /home/jtel/shared/JTELCarrierPortal/Libraries/jtel_udf_udpsend/dummy/jtel_udf_udpsend.so /usr/lib64/mysql/plugin/
chown root:root /usr/lib64/mysql/plugin/jtel_udf_udpsend.so
chmod 755 /usr/lib64/mysql/plugin/jtel_udf_udpsend.so
chcon system_u:object_r:lib_t:s0  /usr/lib64/mysql/plugin/jtel_udf_udpsend.so

Configuration

To configure the plugin, the following commands are executed:

CAUTION PASSWORD

mysql -u root -p<password> -v -e"DROP FUNCTION IF EXISTS udpsend"
mysql -u root -p<password> -v -e"CREATE FUNCTION udpsend RETURNS STRING SONAME 'jtel_udf_udpsend.so'"

Configure Server RAM

In order that the server makes the best use of the RAM available, the configuration file /etc/my.cnf.d/jtel-enhanced-8.cnf must be adapted.

The setting innodb_buffer_pool_size should be adapted to about 3/4 of the available RAM, but a minimum of 3-4 GB should remain for the use of other processes. For Servers with 4 GB RAM, this should not exceed 2 GB. 

# For 4 GB RAM
innodb_buffer_pool_size = 2048M

# For 8 GB RAM
innodb_buffer_pool_size = 5120M
 
# For 12 GB RAM
innodb_buffer_pool_size = 8192M
 
# For 16 GB RAM
innodb_buffer_pool_size = 12288M

...
# From 16 GB simply take 3/4 of the RAM

Restart MySQL

Finally, the MySQL server is restarted for the last time, to load all configuration settings.

systemctl restart mysqld.service