manual:config:triggers

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manual:config:triggers [2011/02/24 14:38]
Vedmak created
manual:config:triggers [2019/02/11 06:57] (current)
martins-v triggers are evaluated based on history only
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-~~DISCUSSION:​off~~+===== - #3 Triggers =====
  
-===== - #3 Triggers=====+=== Overview ​==
 + 
 +Triggers are logical expressions that "​evaluate"​ data gathered by items and represent the current system state.  
 + 
 +While items are used to gather system data, it is highly impractical to follow these data all the time waiting for a condition that is alarming or deserves attention. The job of "​evaluating"​ data can be left to trigger expressions.  
 + 
 +Trigger expressions allow to define a threshold of what state of data is "​acceptable"​. Therefore, should the incoming data surpass the acceptable state, a trigger is "​fired" ​or changes status to PROBLEM. 
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 +A trigger may have the following status: 
 + 
 +^VALUE ​ ^DESCRIPTION^ 
 +|OK     |This is a normal trigger state. Called FALSE in older Zabbix versions.| 
 +|PROBLEM|Normally means that something happened. For example, the processor load is too high. Called TRUE in older Zabbix versions.| 
 + 
 +Trigger status (the expression) is recalculated every time Zabbix server receives a new value that is part of the expression.  
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 +Triggers ​are evaluated based on [[:​manual/​config/​items/​history_and_trends|history]] data only; trend data are never considered. 
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 +If time-based functions (**nodata()**,​ **date()**, **dayofmonth()**,​ **dayofweek()**,​ **time()**, **now()**) are used in the expression, the trigger is recalculated every 30 seconds by a zabbix //timer// process. If both time-based and non-time-based functions are used in an expression, it is recalculated when a new value is received **and** every 30 seconds. 
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 +You can [[manual:​config:​triggers:​expression|build trigger expressions]] with different degrees of complexity.