22

✏️ Editing: dbcluster-config-sample.php

<?php

global $w3tc_dbcluster_config;

$w3tc_dbcluster_config = array(
	/**
	 * Persistent (bool)
	 *
	 * This determines whether to use mysql_connect or mysql_pconnect. The effects
	 * of this setting may vary and should be carefully tested.
	 * Default: false
	 */
	'persistent' => false,

/**
	 * check_tcp_responsiveness
	 *
	 * Enables checking TCP responsiveness by fsockopen prior to mysql_connect or
	 * mysql_pconnect. This was added because PHP's mysql functions do not provide
	 * a variable timeout setting. Disabling it may improve average performance by
	 * a very tiny margin but lose protection against connections failing slowly.
	 * Default: true
	 */
	'check_tcp_responsiveness' => true,

/**
	 * Default is to always (reads & writes) use the master db when user is in administration backend.
	 * Set use_master_in_backend to false to disable this behavior.
	 *
	 * WARNING: if your cluster has any replication delays then when this is enabled, you may not see
	 * any admin changes until the replication catches up with the change written to your master
	 * server and will see old content/configuration until that point in time - You should test this
	 * in your environment fully.
	 */
	'use_master_in_backend' => true,

/**
	 * This set the charset that the db connection should use.
	 * If DB_CHARSET is set there is no need to set $wpdb_cluster->charset.
	 */
	'charset' => DB_CHARSET,

/**
	 * This set the charset that the db connection should use.
	 * If DB_COLLATE is set there is no need to set $wpdb_cluster->collate.
	 */
	'collate' => DB_COLLATE,
	/** Configuration Functions **/

/**
	 * database is an associative array with these parameters:
	 * host             (required) Hostname with optional :port. Default port is 3306.
	 * user             (required) MySQL user name.
	 * password         (required) MySQL user password.
	 * name             (required) MySQL database name.
	 * read             (optional) Whether server is readable. Default is 1 (readable).
	 *			    Also used to assign preference.
	 * write            (optional) Whether server is writable. Default is 1 (writable).
	 *                             Also used to assign preference in multi-master mode.
	 * dataset          (optional) Name of dataset. Default is 'global'.
	 * timeout          (optional) Seconds to wait for TCP responsiveness. Default is 0.2
	 * connect_function (optional) connection function to use
	 * zone             (optional) name of zone where server is located.
	 *                             Used for web applications hosted on cluster
	 *
	 * Read & write
	 * A database definition can include 'read' and 'write' parameters. These
	 * operate as boolean switches but they are typically specified as integers.
	 * They allow or disallow use of the database for reading or writing.
	 *
	 * A master database might be configured to allow reading and writing:
	 *   'write' => true,
	 *   'read'  => true,
	 * while a slave would be allowed only to read:
	 *   'write' => false,
	 *   'read'  => true,
	 *
	 * It might be advantageous to disallow reading from the master, such as when
	 * there are many slaves available and the master is very busy with writes.
	 *   'write' => true,
	 *   'read'  => false,
	 *
	 */
	'databases' => array(
		'master' => array(
			'host'     => DB_HOST,     // If port is other than 3306, use host:port.
			'user'     => DB_USER,
			'password' => DB_PASSWORD,
			'name'     => DB_NAME
		)
	),

/**
	 * Zones (for web applications hosted on cluster)
	 *
	 * When your databases are located in separate physical locations there is
	 * typically an advantage to connecting to a nearby server instead of a more
	 * distant one. This can be configured by defining zones.
	 *
	 * Add 'zone' parameter to add_server call:
	 *     'zone' => 'A'
	 *
	 * Plugin determines where application is running by checking
	 * $_SERVER['SERVER_NAME'] system variable against defined in zone definition
	 * and then connects to servers following defined order:
	 * Value '*' can be used as 'server_names' item to indicate any server.
	 *
	 * 'zones' => array(
	 *     'zone_name' => array(
	 *         'server_names' => array('host1', 'host1.1'),
	 *         'zone_priorities' => array('A', 'B')
	 *   )
	 * )
	 *
	 * As a result it will try to connect to servers in zone A first, then servers
	 * in zone B.
	 */
	'zones' => array(
	),

/**
	 * Filters
	 *
	 * Filters are executed on <tag> event in the order in which they are
	 * registered until one of them returns something other than null.
	 *
	 * Tags:
	 *   'dataset' - fitler will be called with two arguments and expected to
	 *       return a dataset to connect to
	 *       $dataset = $callback($table, &$wpdb);
	 *   'blog_dataset' - fitler will be called with argument $blog_id and
	 *       expected to return a dataset to connect to.
	 *       Used when data are partitioned at blog level
	 *       $dataset = $callback($blog_id);
	 *
	 * 'filters' => array(
	 *     array(
	 *       'tag' => 'tag_to_add',
	 *       'function_to_add' => 'function_name'

* );
	 */
	'filters' => array(
	)
);

/**
 * This adds the same server again, only this time it is configured as a slave.
 * The last three parameters are set to the defaults but are shown for clarity.
 */
/*
$w3tc_dbcluster_config = array(
	'databases' => array(
		'master' => array(
			'host'     => DB_HOST,
			'user'     => DB_USER,
			'password' => DB_PASSWORD,
			'name'     => DB_NAME
		),
		'slave' => array(
			'host'     => DB_HOST,
			'user'     => DB_USER,
			'password' => DB_PASSWORD,
			'name'     => DB_NAME,
			'write'    => false,
			'read'     => true,
			'timeout'  => 0.2,
));
*/

/** Sample Configuration 2: Partitioning **/

/**
 * This example shows a setup where the multisite blog tables have been
 * separated from the global dataset.
 */
/*
$w3tc_dbcluster_config = array(
	'databases' => array(
		'master' => array(
			'host'     => 'global.db.example.com',
			'user'     => 'globaluser',
			'password' => 'globalpassword',
			'name'     => 'globaldb',
		),
		'partition2' => array(
			'host'     => 'blog.db.example.com',
			'user'     => 'bloguser',
			'password' => 'blogpassword',
			'name'     => 'blogdb',
			'dataset'  => 'blog2',
		),
	)
	'filters' => array(
		array(
		    'tag' => 'blog_dataset',
		    'function_to_add' => 'my_db_callback'
		)
	)
);

function my_db_callback($blog_id, $wpdb_cluster) {
    if ($blog_id > 5))
        return 'blog2';
}
*/

MR SKB