Maxscale is proxy that extends the high availability of MariaDB. MariaDB MaxScale is an advanced database proxy, firewall, and query router. MaxScale is a component of MariaDB Platform. MaxScale is compatible with MariaDB Enterprise Server, MariaDB ColumnStore, and MariaDB Community Server. Let's imagine the following configuration:

• 192.168.10.101 node1
• 192.168.10.102 node2
• 192.168.10.103 node3
• 192.168.10.104 node4

The Cluster will be configured as follows:

Maxscale:

• node1

Galera Cluster:

• node2
• node3
• node4

To set up we have to install the packages and configure the repositories. Do that on all nodes in the cluster. In our case on all 4:

[root@node1 ~]#  curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash
[warning] Found existing file at /etc/yum.repos.d/mariadb.repo. Moving to /etc/yum.repos.d/mariadb.repo.old_1
[info] Repository file successfully written to /etc/yum.repos.d/mariadb.repo
[info] Adding trusted package signing keys...
[info] Successfully added trusted package signing keys
[root@node1 ~]#

After that we can install the Maria DB

[root@node1 ~]# yum -y install MariaDB-server
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: ftp.cvut.cz
 * extras: ftp.cvut.cz
 * updates: ftp.cvut.cz
mariadb-main                                                                                                                                                        | 2.9 kB  00:00:00
mariadb-maxscale                                                                                                                                                    | 2.4 kB  00:00:00
mariadb-tools                                                                                                                                                       | 2.9 kB  00:00:00
(1/3): mariadb-maxscale/7/x86_64/primary_db                                                                                                                         | 7.1 kB  00:00:00
(2/3): mariadb-tools/7/x86_64/primary_db                                                                                                                            |  14 kB  00:00:00
(3/3): mariadb-main/7/x86_64/primary_db                                                                                                                             |  70 kB  00:00:00
Resolving Dependencies
--> Running transaction check
---> Package MariaDB-server.x86_64 0:10.5.6-1.el7.centos will be installed
--> Processing Dependency: perl(DBI) for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: libaio.so.1(LIBAIO_0.1)(64bit) for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: MariaDB-client for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: perl(Data::Dumper) for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: galera-4 for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: MariaDB-common for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: lsof for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
--> Processing Dependency: libaio.so.1(LIBAIO_0.4)(64bit) for package: MariaDB-server-10.5.6-1.el7.centos.x86_64
Installed:
  MariaDB-compat.x86_64 0:10.5.6-1.el7.centos                                                  MariaDB-server.x86_64 0:10.5.6-1.el7.centos

Dependency Installed:
  MariaDB-client.x86_64 0:10.5.6-1.el7.centos   MariaDB-common.x86_64 0:10.5.6-1.el7.centos   boost-program-options.x86_64 0:1.53.0-28.el7   galera-4.x86_64 0:26.4.5-1.el7.centos
  libaio.x86_64 0:0.3.109-13.el7                lsof.x86_64 0:4.87-6.el7                      pcre2.x86_64 0:10.23-2.el7                     perl-Compress-Raw-Bzip2.x86_64 0:2.061-3.el7
  perl-Compress-Raw-Zlib.x86_64 1:2.061-4.el7   perl-DBI.x86_64 0:1.627-4.el7                 perl-Data-Dumper.x86_64 0:2.145-3.el7          perl-IO-Compress.noarch 0:2.061-2.el7
  perl-Net-Daemon.noarch 0:0.48-5.el7           perl-PlRPC.noarch 0:0.2020-14.el7             socat.x86_64 0:1.7.3.2-2.el7

Replaced:
  mariadb-libs.x86_64 1:5.5.60-1.el7_5

Install MariaDB Client

[root@node1 ~]# yum -y install MariaDB-client
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: ftp.cvut.cz
 * extras: ftp.cvut.cz
 * updates: ftp.cvut.cz
Package MariaDB-client-10.5.6-1.el7.centos.x86_64 already installed and latest version
Nothing to do
[root@node1 ~]#