create aggregate trigger

[zhujian]

i have a question,once found 3 machine ports down, send an alarm ，what can i do ,use calculated item ?

[zhujian]

I mean three machines in a group are not sure which machine they are,i use this trigger：{Bigdata_Hbase_AlarmAggregate:grpsum["groupname","net.tcp.listen[60020]",last].count(1m,0)}>=3 ，But this configuration is not effective。