Hi All,
We are using elastic stack for monitoring our sflow ,suddenly this morning logstash failed and we were not getting any events to elasticsearch and couldnt see it in kibana.
Then i checked in logstash-plain.log i could see this
Please anyone help me how to fix this and how to approach going forward with these kind of errors,
and is there way to alert in email if the logstash got crashed or not processing the events
Any help would be really helpfull 
Thanks,
Raj