How to set up two memcached server hosts in Joomla cache setting? - joomla

Question

I have set up two instances of memcached running on two servers. How do I set up the hosts in Joomla cache setting?

Answer 1

You have to edit the configuration.php file at the site root folder and add the server details. Find the cache varibles $caching, $cache_handler, $memcache_server_host, $memcache_server_port.
Set them as follows
public $caching = '2';
public $cache_handler = 'memcache';
public $memcache_server_host = 'localhost';//Give your memcache server address
public $memcache_server_port = '11111'; //Memcache server port
In the libraries/joomla/cache/storage/memcache.php file I found this lines
/*
* This will be an array of loveliness
***#todo: multiple servers***
* $servers = (isset($params['servers'])) ? $params['servers'] : array();
*/
As you wanted to add two different memcache servers, you can see that it is still under development. But there is a way ---By hacking core files.
DONT TRY THE METHOD GIVEN BELOW IN PRODUCTION ENVIRONMENT
Though it is dangerous to play with core files but you can do at your own risk by following the method that I will suggest now. take backup first.
Take a backup of the files(configuration.php and libraries/joomla/cache/storage/memcache.php and libraries\vendor\joomla\session\Joomla\Session\Storage\Memcache.php). In the memcache file search for this code in the file
$server['host'] = $config->get('memcache_server_host', 'localhost');
$server['port'] = $config->get('memcache_server_port', 11211);
// Create the memcache connection
self::$_db = new Memcache;
self::$_db->addServer($server['host'], $server['port'], $this->_persistent);
$memcachetest = #self::$_db->connect($server['host'], $server['port']);
if ($memcachetest == false)
{
throw new RuntimeException('Could not connect to memcache server', 404);
}
Add this code below
//Give second server details like this
$server['host2'] = $config->get('memcache_server_host2', 'localhost');
$server['port2'] = $config->get('memcache_server_port2', 11211);
// Create the memcache connection
self::$_db = new Memcache;
self::$_db->addServer($server['host2'], $server['port2'], $this->_persistent);
$memcachetest = #self::$_db->connect($server['host2'], $server['port2']);
if ($memcachetest == false)
{
throw new RuntimeException('Could not connect to memcache server', 404);
}
In the configuration.php file add this lines
public $memcache_server_host2 = 'localhost';//Give your second memcache server address
public $memcache_server_port2 = '11111'; //Memcache second server port
Now for storing sessions you have to edit files that stores session cache
In the file libraries\vendor\joomla\session\Joomla\Session\Storage\Memcache.php you will find these line
$this->_servers = array(
array(
'host' => isset($options['memcache_server_host']) ? $options['memcache_server_host'] : 'localhost',
'port' => isset($options['memcache_server_port']) ? $options['memcache_server_port'] : 11211
)
);
Change this to
$this->_servers = array(
array(
'host' => isset($options['memcache_server_host']) ? $options['memcache_server_host'] : 'localhost',
'port' => isset($options['memcache_server_port']) ? $options['memcache_server_port'] : 11211
),
array(
'host2' => isset($options['memcache_server_host2']) ? $options['memcache_server_host2'] : 'localhost',
'port2' => isset($options['memcache_server_port2']) ? $options['memcache_server_port2'] : 11211
)
);