[3.x]: Craft is not working when Redis server is down

[martinhellwagner]

What happened?

Description

We have the problem that Craft is not working when the Redis server is down. Is it possible that Craft is using the DB for caching as fallback when the Redis server is down?

Steps to reproduce

1. Redis server is down
2. Craft is not working

Expected behavior

Craft should use the DB for caching when the Redis server is down.

Actual behavior

Craft is not working.

Craft CMS version

3.7.27

PHP version

8.0

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

No response

[brandonkelly]

You could accomplish this by setting your cache component config to a callback function, which checks whether Redis is running, and if not, fallback to file (or DB) caching.

return [
    'components' => [
        'cache' => function() {
            try {
                Craft::$app->redis->open();
                $useRedis = true;
            } catch (yii\db\Exception $e) {
                $useRedis = false;
            }

            if ($useRedis) {
                $config = [
                    'class' => yii\redis\Cache::class,
                    'defaultDuration' => 86400,
                    'keyPrefix' => craft\helpers\App::env('APP_ID') ?: 'CraftCMS',
                ];
            } else {
                $config = craft\helpers\App::cacheConfig();
            }
            
            return Craft::createObject($config);
        },
    ],
];

[martinhellwagner]

That makes sense. I'll give it a try. Thank you! 🙂