Nextcloud on Kubernetes with Redis cluster

ℹ️ Support
1

I’ve set up Nextcloud on Kubernetes with a standalone Redis instance.

Now, I’d like to set up a Redis cluster to have the whole setup high available.

Since the helm charts don’t directly support Redis clusters, I configured a custom PHP config as follows:

<?php
        $CONFIG = array (
          'memcache.distributed' => '\OC\Memcache\Redis',
          'memcache.locking' => '\OC\Memcache\Redis',

          'redis' => array(),
          'redis.cluster' => array (
            'seeds' => array(
              'nextcloud-redis-0.nextcloud-redis-headless:6379',
              'nextcloud-redis-1.nextcloud-redis-headless:6379',
              'nextcloud-redis-2.nextcloud-redis-headless:6379',


            ),
            'timeout' => 1.5,
            'read_timeout' => 1.5,
            'failover_mode' => \RedisCluster::FAILOVER_ERROR,
            'password' => getenv('REDIS_HOST_PASSWORD'),
          )
        );

The Nextcloud container starts with this configuration but eventually crashes without any meaningful errors in the container logs. The only thing logged is:

WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

The browser itself eventually reports a 504.

How can I get the Redis cluster to work or at least have a more verbose logging in the container?

2

What about the Nextcloud log?

The container log only logs web/SAPI level matters.

3

It depends on how the Redis cluster is configured. There are different error messages. I tried multi-master, replication and sentinel configuration and each time there are errors about either not being able to write into a read-only replica (even when directed directly to the master service) or not reaching the redis at all.

4

Please be more specific. We need to see actual error messages. Note, Redis Sentinel != Redis Cluster.

There is a support template for a reason. We’re all volunteers. Please respect our time and help us help you.

5

Did you manage to resolve issue with connectiion on redis cluster?

6

No, in the end I gave up and reverted to a standalone Redis pod. We can live with that for the moment.