DB Cluster still doesn’t appear to be orking post 2.4.0 update

Sorry for the separate thread, I can’t update the original anymore here: https://www.boldgrid.com/support/question/database-cluster/

In 2.4.0 there was a fix for this issue: https://github.com/BoldGrid/w3-total-cache/pull/708

However, after installing the update my read replica has yet to have a single connection in the last 2 hours which suggests it’s not working still.

I can now see the DB Cluster settings in the WP backend which is a step in the right direction.

Probably worth mentioning, the WP backend says, ‘Create db-cluster-config.php file with your database cluster configuration to enable it’ and other places online as well as the sample filename mention dbcluster-config.php (slightly different filename) – though I’ve tried under both names without luck. Can you confirm which it should be?

My db-cluster-config.php/dbcluster-config.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,
);

	/** 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,
	 *
	 */

/**
 * 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'     => 'redacted',
			'user'     => DB_USER,
			'password' => DB_PASSWORD,
			'name'     => DB_NAME,
			'write'    => false,
			'read'     => true,
			'timeout'  => 0.4,
)));