I have a field called "eventid" that if it matches a certain value, for example, "2" then I tag it with "alert" and add [@metadata][...] to send to a Zabbix trapper.
The problem is when there is no input with that specific eventid then no data is sent to Zabbix.
Is it possible to send a value of "0" in a interval if there is no eventid=2 in Logstash filter. Mind that I will have to monitor other eventids in the future.