distribuited poller

I configured libre with a DB server, a web server with nginx, the memcached and RRDCACHED service (for images) and two pollers. I have a problem related to the cluster system (distributed poller) and I have read that I should use either the REDIS or the MEMCACHED is correct? I set using the MEMCACHED in the .env file only the entry CACHE_DRIVER = memcached, then in the config.php of the pollers I configured: $ config [‘distributed_poller’] = true;
$ config [‘distributed_poller_name’] = php_uname (‘n’);

$ config [‘distributed_poller_memcached_host’] = “x.x.x.x”;
$ config [‘distributed_poller_memcached_port’] = 11211;
The problem is that the system sees me as a cluster master server but I have a message that says “device unpolled”. If I debug with ./validate.php
[WARN] Using memcached for distributed locking, you should set CACHE_DRIVER = redis
[FAIL] Dispatcher service has not reported stats within the last poller window
Can someone explain to me if it is true that I have to use MEMCACHED as an alternative to REDIS and if my configurations are correct and why the devices are no longer monitored?

You should only be using one of the two. Either the dispatcher service or the cron jobs. Also, have you made sure that all pollers are set to the correct group? The default group is 0.