Can I add loadbalance to filebeat config for hosts in logstash output?

Elastic Stack Beats
2

I don't understand. Can you post sample configs?

e.g.

filebeat:
  ...

  spool_size: 4096

...

output:
  logstash:
    hosts:
      - logstash1:5044
      - logstash2:5044
    loadbalance: true
    bulk_max_size: 2048
    worker: 1

will get you some lock-step load-balancing. For lock-step loadbalancing use spool_size = worker * #hosts * bulk_max_size. Having just one host one can do (2 load balance workers):

filebeat:
  ...

  spool_size: 4096

...

output:
  logstash:
    hosts:
      - logstash:5044
    loadbalance: true
    bulk_max_size: 2048
    worker: 2