Overview

This page details step 4 of the 7-step procedure "Deploy Primary/Replica Topology".

This step tests MariaDB Enterprise Server

Several actions require connection to MariaDB Enterprise Server. A command-line client (mariadb) was included with your ES installation. These instructions describe connection via Unix domain socket. Alternatively, a different client and connection method could be used.

Interactive commands are detailed. Alternatively, the described operations can be performed using automation.

Test Enterprise Server Service

Use Systemd to test whether the MariaDB Enterprise Server service is running.

This action is performed on each Enterprise Server node.

Check if the MariaDB Enterprise Server service is running by executing the following:

$ systemctl status mariadb

If the service is not running on any node, start the service by executing the following on that node:

$ sudo systemctl start mariadb

Test Local Client Connections

Use MariaDB Client to test the local connection to the Enterprise Server node.

This action is performed on each Enterprise Server node:

$ sudo mariadb
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 38
Server version: 11.4.5-3-MariaDB-Enterprise MariaDB Enterprise 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)]>

The sudo command is used here to connect to the Enterprise Server node using the root@localhost user account, which authenticates using the unix_socket authentication plugin. Other user accounts can be used by specifying the --user and --password command-line options.

Test Replica Status

Use SHOW REPLICA STATUS to check that replication is running properly on the replica servers.

This action is performed on each replica server.

Execute the following:

SHOW REPLICA STATUS\G

*************************** 1. row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 192.0.2.1
                   Master_User: repl
                   Master_Port: 3306
                 Connect_Retry: 60
               Master_Log_File: mariadb-bin.000001
           Read_Master_Log_Pos: 645
                Relay_Log_File: li282-189-relay-bin.000002
                 Relay_Log_Pos: 946
         Relay_Master_Log_File: mariadb-bin.000001
              Slave_IO_Running: Yes
             Slave_SQL_Running: Yes
               Replicate_Do_DB:
           Replicate_Ignore_DB:
            Replicate_Do_Table:
        Replicate_Ignore_Table:
       Replicate_Wild_Do_Table:
   Replicate_Wild_Ignore_Table:
                    Last_Errno: 0
                    Last_Error:
                  Skip_Counter: 0
           Exec_Master_Log_Pos: 645
               Relay_Log_Space: 1259
               Until_Condition: None
                Until_Log_File:
                 Until_Log_Pos: 0
            Master_SSL_Allowed: No
            Master_SSL_CA_File:
            Master_SSL_CA_Path:
               Master_SSL_Cert:
             Master_SSL_Cipher:
                Master_SSL_Key:
         Seconds_Behind_Master: 0
 Master_SSL_Verify_Server_Cert: No
                 Last_IO_Errno: 0
                 Last_IO_Error:
                Last_SQL_Errno: 0
                Last_SQL_Error:
   Replicate_Ignore_Server_Ids:
              Master_Server_Id: 1
                Master_SSL_Crl:
            Master_SSL_Crlpath:
                    Using_Gtid: Slave_Pos
                   Gtid_IO_Pos: 0-1-2
       Replicate_Do_Domain_Ids:
   Replicate_Ignore_Domain_Ids:
                 Parallel_Mode: optimistic
                     SQL_Delay: 0
           SQL_Remaining_Delay: NULL
       Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
              Slave_DDL_Groups: 2
Slave_Non_Transactional_Groups: 0
    Slave_Transactional_Groups: 0

If Slave_IO_Running column is not Yes on any replica server, then check:

• The network connectivity between the replica server and the primary server
• The Last_IO_Error column for details on any errors

If Slave_SQL_Running column is not Yes on any replica server, then check:

• The GTID position in gtid_slave_pos
• The Last_SQL_Error column for details on any errors

If both columns are not Yes on any replica server, then check:

• The replication configuration on the replica server.

If you need to make any corrections, the slave threads can be restarted with START REPLICA.

Test DDL

Use MariaDB Client to test DDL.

1. On the primary server, use the MariaDB Client to connect to the node:

$ sudo mariadb

2. Create a test database and table:

CREATE DATABASE IF NOT EXISTS test;

CREATE TABLE test.contacts (
   id INT PRIMARY KEY AUTO_INCREMENT,
   first_name VARCHAR(50),
   last_name VARCHAR(50),
   email VARCHAR(100)
);

3. On each replica server, use the MariaDB Client to connect to the node:

$ sudo mariadb

4. Confirm that the database and table exist:

SHOW CREATE TABLE test.contacts\G;

If the database or table do not exist on any node, then check the replication status on the node.

Test DML

Use MariaDB Client to test DML.

1. On the primary server, use the MariaDB Client to connect to the node:

$ sudo mariadb

2. Insert sample data into the table created in the DDL test:

INSERT INTO test.contacts (first_name, last_name, email)
   VALUES
   ("Kai", "Devi", "kai.devi@example.com"),
   ("Lee", "Wang", "lee.wang@example.com");

3. On each replica server, use the MariaDB Client to connect to the node:

$ sudo mariadb
Execute a SELECT query to retrieve the data:

SELECT * FROM test.contacts;

+----+------------+-----------+----------------------+
| id | first_name | last_name | email                |
+----+------------+-----------+----------------------+
| 1  | Kai        | Devi      | kai.devi@example.com |
| 2  | Lee        | Wang      | lee.wang@example.com |
+----+------------+-----------+----------------------+

If the data is not returned on any node, then check the replication status on the node.

Next Step

Navigation in the procedure "Deploy Primary/Replica Topology":

This page was step 4 of 7.

Next: Step 5: Install MariaDB MaxScale