Debug if output reaches elastic search from logstash

I have log stash configured to send output to both love beat and elastic search. On feeding log stash through filebeat, log stash sends output to love beat immediately, however i don't see the the data sent to elastic search being indexed when the output is of smaller size. How do i debug if output from log stash is reaching elastic search or not?

I guess its due to buffering happening at elastic search before the output from log stash is indexed. How do i change this setting to a lower value in elastic search?

Probably this -