We had a DNS server go down due to overload. Our zabbix server didn't cause it, but it was one of the top 100 users of name services. I found that nscd wasn't running on the zabbix (RHEL) server. Starting nscd took it well out of the list of heavy users and greatly improved Zabbix performance. Our queue is smaller than ever.
Monitoring 200+ hosts, 300+ items per second.
Monitoring 200+ hosts, 300+ items per second.