Logstash warning

I am have metricbeat running on few systems. and getting this error message on and off.

can't put my fingure on about which event is generating this error.

is there a way to find out?

Basically metricbeat is running few hundred nodes and sending data to logstash.
logstash does some processing and saves to Elasticsearch

there are sending event per min.

[2021-02-24T15:36:16,435][WARN ][io.netty.channel.DefaultChannelPipeline] An exceptionCaught() event was fired, and it reached at the tail of the pipelin e. It usually means the last handler in the pipeline did not handle the exception.
java.io.IOException: Connection reset by peer

It could be a firewall in the network causing a disconnect?

There is no firewall involve as they all in same network

 systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)

# cat /etc/selinux/config

SELINUX=disabled

# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination