I want to share wp_users table of my two websites hosting on same server

I have two portal hosting on same server
http://educationspark.com/ (root)

Inside root i have made a folder BLOG where i have put my blog content
see the url below….
http://educationspark.com/BLOG

I have put the db-config file in root of educationspark.com and db.php inside wp-content

Below is the code which i have written in db-config.php

/** Sample Configuration 2: Partitioning **/

/**
 * This example shows a setup where the multisite blog tables have been
 * separated from the global dataset.
 */

$wpdb->add_database(array(
	'host'     => 'estate.websitewelcome.com',
	'user'     => 'educatio_espark',
	'password' => 'SwMZFa^W&m2$',
	'name'     => 'educatio_spark',
));
$wpdb->add_database(array(
	'host'     => 'estate.websitewelcome.com',
	'user'     => 'educatio_BLG12',
	'password' => '4(mn=DDXh)t5',
	'name'     => 'educatio_BLOG',
	'dataset'  => 'users',
));

$wpdb->add_callback('add_shared_users');
function add_shared_users($query, $wpdb) {
	// Multisite blog tables are "{$base_prefix}{$blog_id}_*"
	if ( preg_match("/^{$wpdb->base_prefix}\d+_/i", $wpdb->table) )
		return 'users';

}

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Problem is i have tested the same code in my localhost…code is running fine, user are get shared between two portals…….but when i am using the same code in live site….. users are not get shared.

I want if user register on http://www.educationspark.com/BLOG/ he/she will automatically get registered on http://www.educationspark.com/

Please help me to correct my code.

https://wordpress.org/plugins/hyperdb/