An example of how to use Master/Slave support with mautic. In this case supporting an optional read-only replica cluster with AuroraDB.

config_prod.php

<?php

$loader->import('config.php');

if (file_exists(__DIR__.'/security_local.php')) {
    $loader->import('security_local.php');
} else {
    $loader->import('security.php');
}

/*
$container->loadFromExtension("framework", array(
    "validation" => array(
        "cache" => "apc"
    )
));

$container->loadFromExtension("doctrine", array(
    "orm" => array(
        "metadata_cache_driver" => "apc",
        "result_cache_driver"   => "apc",
        "query_cache_driver"    => "apc"
    )
));
*/

// Read Only db cluster support.
// In future this may be best as a modification of the core config.php.
$dbHostRO = $container->hasParameter('mautic.db_host_ro') ? $container->getParameter('mautic.db_host_ro') : null;
if (!empty($dbHostRO)) {
    // Default from config.php
    $dbalSettings = [
        'driver'   => '%mautic.db_driver%',
        'host'     => '%mautic.db_host%',
        'port'     => '%mautic.db_port%',
        'dbname'   => '%mautic.db_name%',
        'user'     => '%mautic.db_user%',
        'password' => '%mautic.db_password%',
        'charset'  => 'UTF8',
        'types'    => [
            'array'    => 'Mautic\CoreBundle\Doctrine\Type\ArrayType',
            'datetime' => 'Mautic\CoreBundle\Doctrine\Type\UTCDateTimeType',
        ],
        // Prevent Doctrine from crapping out with "unsupported type" errors due to it examining all tables in the database and not just Mautic's
        'mapping_types' => [
            'enum'  => 'string',
            'point' => 'string',
            'bit'   => 'string',
        ],
        'server_version' => '%mautic.db_server_version%',
    ];

    // Add a single slave (which is a load balanced Aurora read-only cluster).
    $dbalSettings['keep_slave'] = true;
    $dbalSettings['slaves'] = [
        'slave1' => [
            'host'     => $dbHostRO,
            'port'     => '%mautic.db_port%',
            'dbname'   => '%mautic.db_name%',
            'user'     => '%mautic.db_user%',
            'password' => '%mautic.db_password%',
            'charset'  => 'UTF8',
        ]
    ];
    $container->loadFromExtension('doctrine', array(
        'dbal' => $dbalSettings
    ));
}

$debugMode = $container->hasParameter('mautic.debug') ? $container->getParameter('mautic.debug') : $container->getParameter('kernel.debug');

$container->loadFromExtension('monolog', [
    'channels' => [
        'mautic',
    ],
    'handlers' => [
        'main' => [
            'formatter'    => $debugMode ? 'mautic.monolog.fulltrace.formatter' : null,
            'type'         => 'fingers_crossed',
            'buffer_size'  => '200',
            'action_level' => ($debugMode) ? 'debug' : 'error',
            'handler'      => 'nested',
            'channels'     => [
                '!mautic',
            ],
        ],
        'nested' => [
            'type'      => 'rotating_file',
            'path'      => '%kernel.logs_dir%/%kernel.environment%.php',
            'level'     => ($debugMode) ? 'debug' : 'error',
            'max_files' => 7,
        ],
        'mautic' => [
            'formatter' => $debugMode ? 'mautic.monolog.fulltrace.formatter' : null,
            'type'      => 'rotating_file',
            'path'      => '%kernel.logs_dir%/mautic_%kernel.environment%.php',
            'level'     => ($debugMode) ? 'debug' : 'notice',
            'channels'  => [
                'mautic',
            ],
            'max_files' => 7,
        ],
    ],
]);

//Twig Configuration
$container->loadFromExtension('twig', [
    'cache'       => '%mautic.tmp_path%/%kernel.environment%/twig',
    'auto_reload' => true,
]);

// Allow overriding config without a requiring a full bundle or hacks
if (file_exists(__DIR__.'/config_override.php')) {
    $loader->import('config_override.php');
}

// Allow local settings without committing to git such as swift mailer delivery address overrides
if (file_exists(__DIR__.'/config_local.php')) {
    $loader->import('config_local.php');
}

Hi @heathdutton . I have been searching the net to find an example of how to setup Mautic with exactly this. I see this is from 2018.

I have gone ahead and setup MySQL replica on two ubuntu servers and am trying to see what is the best way to do what you have done here in this environment. I have asked chatGPT but not sure it is that correct.

Do you have any pointers?