Poller Not Running from Cron

Had a search and found the following;

root@02:/opt/librenms#  mysqladmin -p -u root version
Enter password:
mysqladmin  Ver 9.1 Distrib 10.1.44-MariaDB, for debian-linux-gnu on x86_64
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Server version          10.1.44-MariaDB-0ubuntu0.18.04.1
Protocol version        10
Connection              Localhost via UNIX socket
UNIX socket             /var/run/mysqld/mysqld.sock
Uptime:                 2 hours 46 min 21 sec

Threads: 35  Questions: 4980260  Slow queries: 0  Opens: 432  Flush tables: 1  Open 
tables: 426  Queries per second avg: 498.974

So I put the following as the Unix socket variable?

DB_SOCKET=/var/run/mysqld/mysqld.sock
$config['db_socket'] = '/var/run/mysqld/mysqld.sock';