Birmingham mumbai

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Now, we can check the status of the secondary server to see whether or not it is 
running.
Within the secondary server's MariaDB shell, execute the following command:
SHOW SLAVE STATUS \G; 
Assuming all went well, we should see the following line in the output:
Slave_IO_State: Waiting for master to send event 
If the secondary server isn't running (
Slave_IO_State
 is blank), execute the following 
command:
START SLAVE; 
Next, check the status of the secondary server process again to verify:
SHOW SLAVE STATUS \G;
From this point forward, any data you add to your database on the primary server 
should be replicated to the secondary. To test, add a new record to the 
Employees
 
table on the 
mysampledb
 database on the primary server:
USE mysampledb; 
INSERT INTO Employees VALUES ('Optimus Prime', '100', 'Transformer'); 
On the secondary server, check the same database and table for the new value to 
appear. It may take a second or two:
USE mysampledb; 
SELECT * FROM Employees; 
If you see any errors in the 
Slave_IO_State
 line when you run 
SHOW SLAVE STATUS 
\G
, or your databases aren't synchronizing properly, here are a few things you can 
try. First, make sure that the primary database server is listening for connections on 
0.0.0.0
 port 
3306
. To test this, run this variation of the 
ss
 command to see which 
port the 
mariadb
 process is listening on (it's listed as 
mysqld
):
ss -tulpn | grep mysqld 
Here, we're adding 
\G
, which changes the output to be displayed 
vertically instead of horizontally. 

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Chapter 13