Logstash, collectd and avoiding duplicated data in the ES

Hi
Architectural question here
I'm setting up an ELK environment
There are 2 logstash servers feeding into the ES cluster
Each of the Logstash will have a collectd instance plugin snmp polling the same devices for data redundancy.
I'm trying to work out how to setup the ELK environment to avoid duplicating that collectd polled data.
I see that in filebeat we can use HA concepts but having trouble working out a process with Collected from 2 logstash instances not duplicating polled SNMP data in the ES environment
Thanks