Why are changing Zabbix's triggers status to unknown?

Question

In Zabbix I have an item which I create some triggers for that on below conditions:

1. {Server Template:mysql.slowqueries.last(0,1800)}>{Server Template:mysql.slowqueries.last(0)}
2. {Server Template:mysql.slowqueries.last(0,1800)}<{Server Template:mysql.slowqueries.last(0)}
3. {Server Template:mysql.slowqueries.avg(900)}=0
4. {Server Template:mysql.slowqueries.last(0,1800)}={Server Template:mysql.slowqueries.last(0)}

The first one's Severity is defined as disaster. When the trigger is run its status is UNLNOWN in Monitoring -> Events.

What is the problem? Why is it? And how to resolve it?

Answer 1

UNKNOWN status probably means that Zabbix could not calculate value of your item. Check "Monitoring" -> "Latest data" applying the host filter. To solve the issue you have to troubleshoot mysql.slowqueries items.