Hello there! I use logstash 6.1.0 with logstash-output-nagios-nsca plugin for sending Errors from my log to the nagios server. My config is: input { file { path => "/opt/mylog.log" start_position => "beginning" } } filter { grok { match => { "message" => " ERROR " } add_field => { "found" => "yes" } } } output { if [found] { nagios_nsca { id => "010101" codec => "plain" host => "nagios.server.com" port => 5667 send_nsca_bin => "/opt/nsca/send_nsca" send_nsca_config => "/o...