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--- maria_ha_maxscale [2020/10/23 19:40] – andonovj
+++ maria_ha_maxscale [2020/10/24 18:17] (current) – [Testing the Environment] andonovj
@@ Line 18: / Line 18: @@
   * node4
-=====Setting up=====
+=====Configuration=====
-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:
+The whole processes will go as follows:
+  - Install MariaDB and Maxscale on all nodes
+  - Configure Galera Cluster
+  - Configure Maxscale
+  - Feature tests
+====Setup Repo====
 <Code:bash|Repo Config>
 [root@node1 ~]#  curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash
@@ Line 146: / Line 151: @@
 [root@node4 ~]# service mariadb start
 Redirecting to /bin/systemctl start mariadb.service
-[root@node4 ~]# service mariadb status
-Redirecting to /bin/systemctl status mariadb.service
-● mariadb.service - MariaDB 10.5.6 database server
-   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; disabled; vendor preset: disabled)
-  Drop-In: /etc/systemd/system/mariadb.service.d
-           └─migrated-from-my.cnf-settings.conf
-   Active: active (running) since Thu 2020-10-22 17:13:11 UTC; 5s ago
-     Docs: man:mariadbd(8)
-           https://mariadb.com/kb/en/library/systemd/
-  Process: 23170 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
-  Process: 22993 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`cd /usr/bin/..; /usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
-  Process: 22991 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
- Main PID: 23042 (mariadbd)
-   Status: "Taking your SQL requests now..."
-   CGroup: /system.slice/mariadb.service
-           └─23042 /usr/sbin/mariadbd --wsrep_start_position=00000000-0000-0000-0000-000000000000:2
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 0 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 5)
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 2 [Note] WSREP: Server node4 synced with group
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 2 [Note] WSREP: Server status change joined -> synced
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 2 [Note] WSREP: Synchronized with group, ready for connections
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 2 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 0 [Note] Reading of all Master_info entries succeeded
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 0 [Note] Added new Master_info '' to hash table
-Oct 22 17:13:11 node4 mariadbd[23042]: 2020-10-22 17:13:11 0 [Note] /usr/sbin/mariadbd: ready for connections.
-Oct 22 17:13:11 node4 mariadbd[23042]: Version: '10.5.6-MariaDB'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MariaDB Server
-Oct 22 17:13:11 node4 systemd[1]: Started MariaDB 10.5.6 database server.
 </Code>
 After that, we can see that the members of the cluster increased:
 <Code:bash|Cluster members>
@@ Line 190: / Line 167: @@
 </Code>
-====Setup Users for MaxScale====
+====Prepare users for MaxScale====
 First we need to set up a user that MariaDB MaxScale use to attach to the cluster to get authentication data. On 192.168.10.182, using the MariaDB command line as the database root user:
@@ Line 220: / Line 197: @@
 </Code>
-====Configure MaxScale====
+====Setup MaxScale====
 The configuration of MaxScale is stored in: "/etc/maxscale.cnf"
 <Code:bash|Maxscale Config>
-[root@node1 ~]# cat /etc/maxscale.cnf
 # Globals
 [maxscale]
 threads=1
-admin_secure_gui=false
+admin_secure_gui=false                 <- We don't have SSL, we aren't so rich.
-admin_host=192.168.10.101
+admin_host=192.168.10.101              <- Defining NIC interface instead of localhst: 127.0.0.1
-admin_port=8989
+admin_port=8989                        <- Default port.
 # Servers
@@ Line 274: / Line 250: @@
 address=192.168.10.101
 port=3306
-[root@node1 ~]#
 </Code>
+It took my REALLY LONG TIME, to figure out the configurations as they change from release to release. Like every open source software....
+After that we can start the maxscale:
+<Code:bash|Start MaxScale>
+[root@node1 maxscale]# service maxscale start
+Redirecting to /bin/systemctl start maxscale.service
+</Code>
+=====Testing the Environment====
+In our test:
+  - We will connect to the listener on the maxscale server
+  - Check the server (e.g. server 3)
+  - Shutdown the MariaDB on the server from step 2)
+  - Check the server from our connection (we should be moved)
+<Code:bash|Session on node1>
+[root@node1 maxscale]# mysql -h 192.168.10.101 -P 3306 -u myuser -p
+Enter password:
+Welcome to the MariaDB monitor.  Commands end with ; or \g.
+Your MariaDB connection id is 1
+Server version: 10.5.6-MariaDB MariaDB Server
+Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
+Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
+MariaDB [(none)]> show variables like 'hostname';
++---------------+-------+
+| Variable_name | Value |
++---------------+-------+
+| hostname      | node3 |
++---------------+-------+
+</Code>
+Now from the session, connected on node3, shutdown the MariaDB:
+<Code:bash|Session on node 3>
+[root@node3 ~]# systemctl stop mariadb.service
+</Code>
+Once we shut down the instance, our session should be moved to running server, so let's check it.
+From the first session, without reconnected, re-query the same data.
+<Code:bash|Session on node1>
+MariaDB [(none)]> show variables like 'hostname';
++---------------+-------+
+| Variable_name | Value |
++---------------+-------+
+| hostname      | node4 |
++---------------+-------+
+row in set (0.001 sec)
+</Code>
+After, we can also connect to the GUI, which should listen on: http://192.168.10.101:8989
+===GUI===
+{{ :mariadbmaxscaleentry.jpg?600 |}}
+The default credentials are:
+Username: admin
+Password: mariadb
+{{ :mariadbmaxscaleoverview.jpg?800 |}}