使用不同的PHP版本从服务器B上的PHP mysqli访问服务器A上的MySql数据库

I'm trying to figure out, how is possible to retrieve records from MySql database tables, located on the server A, which is PHP Version 5.3.29 from server B php mysqli PHP Version 7.2.8

I found this example How to Connect to the Remote MySQL Database using PHP, but I don't understand, how it works in relation to what I'm trying to do, doubt if it is what I'm looking for

I'm new with php, and all that I can imagine, I should be to use connection data from server A for php mysqli on server B, and add access host IP of server B in Remote MySQL of server A, and seems like I have to add database user and password in MySQL databases on server A, but I'm not sure, where do I have to get it on server B

Server A:

Version by phpinfo();: PHP Version 5.3.29

Database server

Server: Localhost via UNIX socket
Server type: MySQL
Server version: 5.6.39 - MySQL Community Server (GPL)
Protocol version: 10
Server charset: UTF-8 Unicode (utf8)

Web server

cpsrvd 11.70.0.51
Database client version: libmysql - 5.1.73
PHP extension: mysqliDocumentation curlDocumentation mbstringDocumentation
PHP version: 5.6.30

phpMyAdmin

Version information: 4.7.7

Server B:

Version by phpinfo();: PHP Version 7.2.8

Database server

Server: Localhost via UNIX socket
Server type: MariaDB
Server version: 5.5.56-MariaDB - MariaDB Server
Protocol version: 10
Server charset: UTF-8 Unicode (utf8)

Web server

nginx/1.11.10
Database client version: libmysql - mysqlnd 5.0.11-dev - $Id: 
PHP extension: mysqliDocumentation curlDocumentation mbstringDocumentation
PHP version: 5.6.30

phpMyAdmin

Version information: 4.6.6

Any advice, guide or example would be very helpful

Edit:

My attempt by answer, first of all I've added IP of server B in Remote MySQL on server A. My conn.php, located on Server B to connect to Server A:

<?php
$servername = "Server_A_IP";
$username = "Server_A_database_user";
$password = "Server_A_database_user_password";
$db = "Server_A_database";

$conn = new mysqli($servername, $username, $password, $db);
$conn->set_charset('utf8');

if(!$conn)
{
    die ("Error on the Connection" . $conn->connect_error);
}
?>

and dbtab.php also located on Server B with conn.php in same folder:

<?php
 include 'conn.php';
$sql = "SELECT * FROM tab";
$result = $conn->query($sql);
?>
<!DOCTYPE html>
<html>
    <h1 align="center">Database</h1>
    <table border="1" align="center" style="line-height:25px;">
    <tr>
    <th colspan="2">Records</th>
    </tr>
    <tr>
    <th bgcolor="#ff897f">id</td> 
    <th bgcolor="#ff897f">name</td>   
    </tr>
<?php
if($result->num_rows > 0)
{
   while($row = $result->fetch_assoc())
   {
    ?>
     <tr>
        <td bgcolor="#e5cac8"><?php echo $row['id']; ?></td>
        <td bgcolor="#e5cac8"><?php echo $row['name']; ?></td>
    <?php
   }
}
else
{
    ?>
    <tr>
    <th colspan="2">There's No data found!!!</th>
    </tr>
    <?php 
}
?>
</body>
</html>

but in result, when I'm tying to open www.site.com/folder/dbtab.php or www.site.com/folder/conn.php, page does not load, just freezes

ping of Server A:

enter image description here

You don't need php on Server A for this. You just need to configure your MySQL Server (Server A) to

  1. allow network access (via IP-addresses) and
  2. create a MySQL Account for the IP-address of Server B

If you have set up this you can create a connection from php on Server B by using

$mysqli = new mysqli("<IP of Server A>", "user", "password", "database");

see the excellent php website on this: mysqli Connections

The steps 1, 2 depend on your MySQL Server. If you have direct root access you need to edit the configuration files and allow networking, otherwise it depends on the hosting service.

To create a user account with remote access issue the following SQL statement (or use a web GUI):

GRANT <Rights> ON <db-name>.* TO 'username'@'<IP of Server B>';

see the MySql manual on granting privileges to users: https://dev.mysql.com/doc/refman/5.5/en/grant.html